diff --git a/types/aws-lambda/README.md b/types/aws-lambda/README.md
new file mode 100644
index 0000000000..135d7a7a57
--- /dev/null
+++ b/types/aws-lambda/README.md
@@ -0,0 +1,189 @@
+Types helpful for implementing handlers in the AWS Lambda NodeJS runtimes,
+the handler interface and types for AWS-defined trigger sources.
+
+Unrelated to the npm package `aws-lambda`, a CLI tool.
+
+## Contributing
+
+Follow all the rules for [modifying a type package](../../README.md#edit-an-existing-package),
+of course, but as this package has gotten quite large, please
+also follow the established conventions to keep things simple
+for future contributors:
+
+### Common types
+
+The main entry point, [index.d.ts]() simply does `export * from "..."`
+for all type declaration files in the package. Make sure if you are
+adding any files for new trigger sources that you add the
+re-export here; the user should only need to import from `"aws-lambda"`.
+
+Similarly, [aws-lambda-tests.ts]() has declarations for the common type and tests
+for [handler.d.ts](), while the actual service specific tests are all in [test/]()
+
+The mentioned [handler.d.ts]() contains definitions for `Handler<TEvent, TResult>`
+and its associated types like `Context` and `Callback<TResult>`,
+which describe the Lambda NodeJS runtime API.
+
+### Triggers
+
+Each trigger-specific event structure should have a separate file in [trigger/]() based
+on the service name and optionally the trigger type, if it's not a clear "default".
+
+If multiple triggers for a service share types, the common types
+should be in a file in [common/]() named for the containing service.
+
+For a service `foo` and trigger `bar`, there should ideally be
+a file `trigger/foo-bar.d.ts` containing something like:
+
+```ts
+import { Callback, Handler } from "../handler";
+
+import { FooCommonType } from "../common/foo";
+
+export type FooBarHandler = Handler<FooBarEvent, FooBarResult>;
+export type FooBarCallback = Callback<FooBarResult>;
+// or, if there is no FooBarResult:
+export type FooBarHandler = Handler<FooBarEvent, void>;
+
+export interface FooBarEvent {
+  // ...
+}
+
+export interface FooBarEventSpecificType {
+  // ...
+}
+
+export interface FooBarResult {
+  // ...
+}
+
+export interface FooBarResultSpecificType {
+    // ...
+}
+
+export interface FooBarCommonType {
+    // ...
+}
+
+// ...
+```
+
+As implied, all names are exported flat, try to ensure that it's clear what service
+or trigger a type is for. (Note that especially the earlier types are not always
+consistent with this)
+
+### Tests
+
+Each trigger should have a type test that exercises the type roughly as the user
+would, in particular reading properties from the event, and creating each
+valid result structure in general. When making any change: adding a property,
+to a new trigger, also add the change to the tests.
+
+Tests are grouped by each service in [test/](), and must also be explicitly
+added to `tsconfig.json`'s `files` list (use of `include` is banned by
+DefinitelyTyped at the moment).
+
+The test file for a service `foo` with two triggers `bar` and `baz` may look like:
+
+```ts
+import {
+    FooBarHandler,
+    FooBarResult,
+    // ...
+ } from "aws-lambda";
+
+const barHandler: FooBarHandler = async (event, context, callback) => {
+    // Check event type
+    // Declarations for e.g. strOrNull, bool are in aws-lambda-tests.ts
+    strOrNull = event.body;
+    str = event.headers[str];
+    str = event.multiValueHeaders[str][num];
+    str = event.httpMethod;
+    bool = event.isBase64Encoded;
+    // this property is of a named type, validate that:
+    let requestContext: FooBarEventRequestContext;
+    requestContext = event.requestContext;
+    // for each accessible property declared in FooBarEvent...
+
+    // recurse into each declared type
+    str = requestContext.accountId;
+    str = requestContext.apiId;
+    const authContext: AuthResponseContext | null | undefined = requestContext.authorizer;
+    numOrUndefined = requestContext.connectedAt;
+    strOrUndefined = requestContext.connectionId;
+    // ...
+
+
+    // Check result type
+    let result: FooBarResult;
+    // check minimally assignable case
+    result = {
+        statusCode: num,
+        body: str,
+    };
+    // check maximally assignable case
+    result = {
+        statusCode: num,
+        headers: {
+            [str]: str,
+            [str]: bool,
+            [str]: num,
+        },
+        multiValueHeaders: {
+            [str]: [str, bool, num],
+        },
+        isBase64Encoded: true,
+        body: str,
+    };
+
+    // check reasonable result-returning styles
+    callback(new Error());
+    callback(null, result);
+    return result;
+};
+
+const bazHandler: FooBazHandler = async (event, context, callback) => {
+    // ... as above, for each untested type
+
+    // for handlers without a result
+    callback();
+    callback(new Error());
+};
+
+...
+```
+
+Not that currently many tests have not been updated to this style.
+As always, PRs welcome, but simply adding your change in the new style
+is a start.
+
+Ideally the existing test should still pass with your new change: if it doesn't that
+implies that your change is incompatible with existing user code (if the
+test is done correctly) This isn't always the wrong thing to do, but be
+prepared to make a decently strong case for why this is an exception.
+
+## Future ideas
+
+* Adding JSDocs for types and properties (copied from AWS docs?). Many
+  triggers have unintuitive formats and requirements.
+
+* Splitting `import { Context, FooBarHandler, FooCommonType } from "aws-lambda"` into
+
+  * `import { Context } from "@aws-lambda/runtime"` and
+  * `import { BarHandler, CommonType } from "@aws-lambda/foo"`
+
+  With forwarding from the current package to preserve back-compat.
+  This would allow not only more fine-grained dependencies, but also
+  support backward-incompatible changes to triggers as they could be
+  independently major versioned.
+
+  It's a lot of busywork to do all that renaming though, and ensuring
+  compatibility is kept.
+
+* Possibly related to the above, migrating this to, or somehow in support of,
+  an npm package with runtime support for implementing handlers correctly.
+  For example, catching and formatting `ClientError` into an API Gateway
+  400 error, or parsing CloudWatch log payloads.
+
+  This one is much more fraught, as it by default loses all the existing
+  DefinitelyTyped tooling and community support (e.g. cross package typing).
diff --git a/types/aws-lambda/aws-lambda-tests.ts b/types/aws-lambda/aws-lambda-tests.ts
index 2403f1c63d..d055f28ed7 100644
--- a/types/aws-lambda/aws-lambda-tests.ts
+++ b/types/aws-lambda/aws-lambda-tests.ts
@@ -1,3 +1,9 @@
+// Declare a bunch of basic types up front. Since this file has no imports
+// or exports, typescript treats these as global declarations that can be
+// used in tests/* files.
+// Don't add declarations for service-specific types here; i.e. not from
+// common/ or trigger/, but handler.d.ts is fine. Those can be in the
+// service-specific tests in tests/{service}-tests.ts
 declare let str: string;
 declare let strOrNull: string | null;
 declare let strOrUndefined: string | undefined;
@@ -10,533 +16,15 @@ declare let bool: boolean;
 declare let boolOrUndefined: boolean | undefined;
 declare let boolOrNumOrStr: boolean | number | string;
 declare let numOrUndefined: number | undefined;
-declare let apiGwEvtReqCtx: AWSLambda.APIGatewayEventRequestContext;
-declare let apiGwEvtReqCtxOpt: AWSLambda.APIGatewayEventRequestContext | null | undefined;
-declare let apiGwEvt: AWSLambda.APIGatewayEvent;
-declare let albEvtReqCtx: AWSLambda.ALBEventRequestContext;
-declare let albEvt: AWSLambda.ALBEvent;
-declare let albRes: AWSLambda.ALBResult;
-declare let customAuthorizerEvt: AWSLambda.CustomAuthorizerEvent;
+
+// handler.d.ts types
+declare let context: AWSLambda.Context;
 declare let clientCtx: AWSLambda.ClientContext;
 declare let clientCtxOrUndefined: AWSLambda.ClientContext | undefined;
 declare let clientContextEnv: AWSLambda.ClientContextEnv;
 declare let clientContextClient: AWSLambda.ClientContextClient;
-declare let context: AWSLambda.Context;
 declare let identity: AWSLambda.CognitoIdentity;
 declare let identityOrUndefined: AWSLambda.CognitoIdentity | undefined;
-declare let proxyResult: AWSLambda.ProxyResult;
-declare let authResponse: AWSLambda.AuthResponse;
-declare let policyDocument: AWSLambda.PolicyDocument;
-declare let statement: AWSLambda.Statement;
-declare let authResponseContext: AWSLambda.AuthResponseContext;
-declare let authResponseContextOpt: AWSLambda.AuthResponseContext | null | undefined;
-declare let snsEvt: AWSLambda.SNSEvent;
-declare let snsEvtRecs: AWSLambda.SNSEventRecord[];
-declare let snsEvtRec: AWSLambda.SNSEventRecord;
-declare let snsMsg: AWSLambda.SNSMessage;
-declare let snsMsgAttr: AWSLambda.SNSMessageAttribute;
-declare let snsMsgAttrs: AWSLambda.SNSMessageAttributes;
-const S3EvtRec: AWSLambda.S3EventRecord = {
-    eventVersion: '2.1',
-    eventSource: 'aws:s3',
-    awsRegion: 'us-east-1',
-    eventTime: '1970-01-01T00:00:00.000Z',
-    eventName: 'ObjectRestore:Completed',
-    userIdentity: {
-        principalId: 'AIDAJDPLRKLG7UEXAMPLE',
-    },
-    requestParameters: {
-        sourceIPAddress: '127.0.0.1',
-    },
-    responseElements: {
-        'x-amz-request-id': 'C3D13FE58DE4C810',
-        'x-amz-id-2': 'FMyUVURIY8/IgAtTv8xRjskZQpcIZ9KG4V5Wp6S7S/JRWeUWerMUE5JgHvANOjpD',
-    },
-    s3: {
-        s3SchemaVersion: '1.0',
-        configurationId: 'testConfigRule',
-        bucket: {
-            name: 'mybucket',
-            ownerIdentity: {
-                principalId: 'A3NL1KOZZKExample',
-            },
-            arn: 'arn:aws:s3:::mybucket',
-        },
-        object: {
-            key: 'HappyFace.jpg',
-            size: 1024,
-            eTag: 'd41d8cd98f00b204e9800998ecf8427e',
-            versionId: '096fKKXTRTtl3on89fVO.nfljtsv6qko',
-            sequencer: '0055AED6DCD90281E5',
-        },
-    },
-    glacierEventData: {
-        restoreEventData: {
-            lifecycleRestorationExpiryTime: '1970-01-01T00:00:00.000Z',
-            lifecycleRestoreStorageClass: 'glacier-deep-archive',
-        },
-    },
-};
-
-const S3CreateEvent: AWSLambda.S3CreateEvent = {
-    Records: [S3EvtRec],
-};
-
-declare const cognitoUserPoolEvent: AWSLambda.CognitoUserPoolEvent;
-declare const cloudformationCustomResourceEvent: AWSLambda.CloudFormationCustomResourceEvent;
-declare const cloudformationCustomResourceResponse: AWSLambda.CloudFormationCustomResourceResponse;
-declare const cloudwatchLogsEvent: AWSLambda.CloudWatchLogsEvent;
-declare const cloudwatchLogsDecodedData: AWSLambda.CloudWatchLogsDecodedData;
-declare const scheduledEvent: AWSLambda.ScheduledEvent;
-
-/* API Gateway Event request context */
-str = apiGwEvtReqCtx.accountId;
-str = apiGwEvtReqCtx.apiId;
-authResponseContextOpt = apiGwEvtReqCtx.authorizer;
-numOrUndefined = apiGwEvtReqCtx.connectedAt;
-strOrUndefined = apiGwEvtReqCtx.connectionId;
-strOrUndefined = apiGwEvtReqCtx.domainName;
-strOrUndefined = apiGwEvtReqCtx.eventType;
-strOrUndefined = apiGwEvtReqCtx.extendedRequestId;
-str = apiGwEvtReqCtx.httpMethod;
-strOrNull = apiGwEvtReqCtx.identity.accessKey;
-strOrNull = apiGwEvtReqCtx.identity.accountId;
-strOrNull = apiGwEvtReqCtx.identity.apiKey;
-strOrNull = apiGwEvtReqCtx.identity.apiKeyId;
-strOrNull = apiGwEvtReqCtx.identity.caller;
-strOrNull = apiGwEvtReqCtx.identity.cognitoAuthenticationProvider;
-strOrNull = apiGwEvtReqCtx.identity.cognitoAuthenticationType;
-strOrNull = apiGwEvtReqCtx.identity.cognitoIdentityId;
-strOrNull = apiGwEvtReqCtx.identity.cognitoIdentityPoolId;
-strOrNull = apiGwEvtReqCtx.identity.principalOrgId;
-str = apiGwEvtReqCtx.identity.sourceIp;
-strOrNull = apiGwEvtReqCtx.identity.user;
-strOrNull = apiGwEvtReqCtx.identity.userAgent;
-strOrNull = apiGwEvtReqCtx.identity.userArn;
-strOrUndefined = apiGwEvtReqCtx.messageDirection;
-strOrUndefinedOrNull = apiGwEvtReqCtx.messageId;
-str = apiGwEvtReqCtx.path;
-str = apiGwEvtReqCtx.stage;
-str = apiGwEvtReqCtx.requestId;
-strOrUndefined = apiGwEvtReqCtx.requestTime;
-str = apiGwEvtReqCtx.resourceId;
-str = apiGwEvtReqCtx.resourcePath;
-strOrUndefined = apiGwEvtReqCtx.routeKey;
-
-/* API Gateway Event */
-strOrNull = apiGwEvt.body;
-str = apiGwEvt.headers['example'];
-str = apiGwEvt.multiValueHeaders['example'][0];
-str = apiGwEvt.httpMethod;
-bool = apiGwEvt.isBase64Encoded;
-str = apiGwEvt.path;
-str = apiGwEvt.pathParameters!['example'];
-str = apiGwEvt.queryStringParameters!['example'];
-str = apiGwEvt.multiValueQueryStringParameters!['example'][0];
-str = apiGwEvt.stageVariables!['example'];
-apiGwEvtReqCtx = apiGwEvt.requestContext;
-str = apiGwEvt.resource;
-
-/* Application Load Balancer Event Request Context */
-str = albEvtReqCtx.elb.targetGroupArn;
-
-/* Application Load Balancer Event */
-str = albEvt.httpMethod;
-str = albEvt.path;
-str = albEvt.queryStringParameters!['example'];
-str = albEvt.headers!['example'];
-str = albEvt.multiValueQueryStringParameters!['example'][0];
-str = albEvt.multiValueHeaders!['example'][0];
-strOrNull = albEvt.body;
-bool = albEvt.isBase64Encoded;
-
-/* Application Load Balancer Result */
-num = albRes.statusCode;
-str = albRes.statusDescription;
-boolOrNumOrStr = albRes.headers!['example'];
-boolOrNumOrStr = albRes.multiValueHeaders!['example'][0];
-strOrUndefined = albRes.body;
-bool = albRes.isBase64Encoded;
-
-/* API Gateway CustomAuthorizer Event */
-str = customAuthorizerEvt.type;
-str = customAuthorizerEvt.methodArn;
-strOrUndefined = customAuthorizerEvt.authorizationToken;
-strOrUndefined = customAuthorizerEvt.resource;
-strOrUndefined = customAuthorizerEvt.path;
-strOrUndefined = customAuthorizerEvt.httpMethod;
-str = customAuthorizerEvt.headers!['example'];
-str = customAuthorizerEvt.multiValueHeaders!['example'][0];
-str = customAuthorizerEvt.pathParameters!['example'];
-str = customAuthorizerEvt.queryStringParameters!['example'];
-str = customAuthorizerEvt.multiValueQueryStringParameters!['example'][0];
-str = customAuthorizerEvt.stageVariables!['example'];
-apiGwEvtReqCtxOpt = customAuthorizerEvt.requestContext;
-strOrUndefined = customAuthorizerEvt.domainName;
-strOrUndefined = customAuthorizerEvt.apiId;
-
-/* DynamoDB Stream Event */
-const dynamoDBStreamEvent: AWSLambda.DynamoDBStreamEvent = {
-    Records: [
-        {
-            eventID: '1',
-            eventVersion: '1.0',
-            dynamodb: {
-                Keys: {
-                    Id: {
-                        N: '101',
-                    },
-                },
-                NewImage: {
-                    Message: {
-                        S: 'New item!',
-                    },
-                    Id: {
-                        N: '101',
-                    },
-                },
-                StreamViewType: 'NEW_AND_OLD_IMAGES',
-                SequenceNumber: '111',
-                SizeBytes: 26,
-            },
-            awsRegion: 'us-west-2',
-            eventName: 'INSERT',
-            eventSourceARN:
-                'arn:aws:dynamodb:us-west-2:account-id:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899',
-            eventSource: 'aws:dynamodb',
-        },
-        {
-            eventID: '2',
-            eventVersion: '1.0',
-            dynamodb: {
-                OldImage: {
-                    Message: {
-                        S: 'New item!',
-                    },
-                    Id: {
-                        N: '101',
-                    },
-                },
-                SequenceNumber: '222',
-                Keys: {
-                    Id: {
-                        N: '101',
-                    },
-                },
-                SizeBytes: 59,
-                NewImage: {
-                    Message: {
-                        S: 'This item has changed',
-                    },
-                    Id: {
-                        N: '101',
-                    },
-                },
-                StreamViewType: 'NEW_AND_OLD_IMAGES',
-            },
-            awsRegion: 'us-west-2',
-            eventName: 'MODIFY',
-            eventSourceARN:
-                'arn:aws:dynamodb:us-west-2:account-id:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899',
-            eventSource: 'aws:dynamodb',
-        },
-        {
-            eventID: '3',
-            eventVersion: '1.0',
-            dynamodb: {
-                Keys: {
-                    Id: {
-                        N: '101',
-                    },
-                },
-                SizeBytes: 38,
-                SequenceNumber: '333',
-                OldImage: {
-                    Message: {
-                        S: 'This item has changed',
-                    },
-                    Id: {
-                        N: '101',
-                    },
-                },
-                StreamViewType: 'NEW_AND_OLD_IMAGES',
-            },
-            awsRegion: 'us-west-2',
-            eventName: 'REMOVE',
-            eventSourceARN:
-                'arn:aws:dynamodb:us-west-2:account-id:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899',
-            eventSource: 'aws:dynamodb',
-        },
-    ],
-};
-
-/* SNS Event */
-snsEvtRecs = snsEvt.Records;
-
-str = snsEvtRec.EventSource;
-str = snsEvtRec.EventSubscriptionArn;
-str = snsEvtRec.EventVersion;
-snsMsg = snsEvtRec.Sns;
-
-str = snsMsg.SignatureVersion;
-str = snsMsg.Timestamp;
-str = snsMsg.Signature;
-str = snsMsg.SigningCertUrl;
-str = snsMsg.MessageId;
-str = snsMsg.Message;
-snsMsgAttrs = snsMsg.MessageAttributes;
-str = snsMsg.Type;
-str = snsMsg.UnsubscribeUrl;
-str = snsMsg.TopicArn;
-str = snsMsg.Subject;
-
-snsMsgAttrs['example'] = snsMsgAttr;
-
-str = snsMsgAttr.Type;
-str = snsMsgAttr.Value;
-
-/* Lambda Proxy Result */
-num = proxyResult.statusCode;
-proxyResult.headers!['example'] = str;
-proxyResult.headers!['example'] = bool;
-proxyResult.headers!['example'] = num;
-proxyResult.multiValueHeaders!['example'][0] = str;
-proxyResult.multiValueHeaders!['example'][0] = bool;
-proxyResult.multiValueHeaders!['example'][0] = num;
-boolOrUndefined = proxyResult.isBase64Encoded;
-str = proxyResult.body;
-
-/* API Gateway CustomAuthorizer AuthResponse */
-authResponseContext = {
-    stringKey: str,
-    numberKey: num,
-    booleanKey: bool,
-};
-
-statement = {
-    Action: str,
-    Effect: str,
-    Resource: str,
-};
-
-// $ExpectError
-statement = { Effect: str, Action: str, Principal: 123, };
-
-// Bad Resource
-// $ExpectError
-statement = { Effect: str, Action: str, Resource: 123, };
-
-// Bad Resource with valid Principal
-// $ExpectError
-statement = { Effect: str, Action: str, Principal: { Service: str }, Resource: 123, };
-
-// Bad principal with valid Resource
-// $ExpectError
-statement = { Effect: str, Action: str, Principal: 123, Resource: str, };
-
-// No Effect
-// $ExpectError
-statement = {
-    Action: str,
-    Principal: str,
-};
-
-statement = {
-    Sid: str,
-    Action: [str, str],
-    Effect: str,
-    Resource: [str, str],
-    Condition: {
-        condition1: { key: 'value' },
-        condition2: [
-            {
-                key1: 'value',
-                key2: 'value',
-            },
-            {
-                key3: 'value',
-            },
-        ],
-    },
-    Principal: [str, str],
-    NotPrincipal: [str, str],
-};
-
-statement = {
-    Action: str,
-    Principal: str,
-    Effect: str,
-};
-
-statement = {
-    Action: str,
-    NotPrincipal: {
-        Service: str,
-    },
-    Effect: str,
-};
-
-statement = {
-    Effect: str,
-    NotAction: str,
-    NotResource: str,
-};
-
-policyDocument = {
-    Version: str,
-    Statement: [statement],
-};
-
-policyDocument = {
-    Version: str,
-    Statement: [statement, statement],
-};
-
-authResponse = {
-    principalId: str,
-    policyDocument,
-    context: authResponseContext,
-};
-
-authResponse = {
-    principalId: str,
-    policyDocument,
-};
-
-// CognitoUserPoolEvent
-num = cognitoUserPoolEvent.version;
-cognitoUserPoolEvent.triggerSource === 'PreSignUp_SignUp';
-cognitoUserPoolEvent.triggerSource === 'PreSignUp_ExternalProvider';
-cognitoUserPoolEvent.triggerSource === 'PostConfirmation_ConfirmSignUp';
-cognitoUserPoolEvent.triggerSource === 'PreAuthentication_Authentication';
-cognitoUserPoolEvent.triggerSource === 'PostAuthentication_Authentication';
-cognitoUserPoolEvent.triggerSource === 'CustomMessage_SignUp';
-cognitoUserPoolEvent.triggerSource === 'CustomMessage_AdminCreateUser';
-cognitoUserPoolEvent.triggerSource === 'CustomMessage_ResendCode';
-cognitoUserPoolEvent.triggerSource === 'CustomMessage_ForgotPassword';
-cognitoUserPoolEvent.triggerSource === 'CustomMessage_UpdateUserAttribute';
-cognitoUserPoolEvent.triggerSource === 'CustomMessage_VerifyUserAttribute';
-cognitoUserPoolEvent.triggerSource === 'CustomMessage_Authentication';
-cognitoUserPoolEvent.triggerSource === 'DefineAuthChallenge_Authentication';
-cognitoUserPoolEvent.triggerSource === 'CreateAuthChallenge_Authentication';
-cognitoUserPoolEvent.triggerSource === 'VerifyAuthChallengeResponse_Authentication';
-cognitoUserPoolEvent.triggerSource === 'PreSignUp_AdminCreateUser';
-cognitoUserPoolEvent.triggerSource === 'PostConfirmation_ConfirmForgotPassword';
-cognitoUserPoolEvent.triggerSource === 'TokenGeneration_HostedAuth';
-cognitoUserPoolEvent.triggerSource === 'TokenGeneration_Authentication';
-cognitoUserPoolEvent.triggerSource === 'TokenGeneration_NewPasswordChallenge';
-cognitoUserPoolEvent.triggerSource === 'TokenGeneration_AuthenticateDevice';
-cognitoUserPoolEvent.triggerSource === 'TokenGeneration_RefreshTokens';
-cognitoUserPoolEvent.triggerSource === 'UserMigration_Authentication';
-cognitoUserPoolEvent.triggerSource === 'UserMigration_ForgotPassword';
-str = cognitoUserPoolEvent.region;
-str = cognitoUserPoolEvent.userPoolId;
-strOrUndefined = cognitoUserPoolEvent.userName;
-str = cognitoUserPoolEvent.callerContext.awsSdkVersion;
-str = cognitoUserPoolEvent.callerContext.clientId;
-str = cognitoUserPoolEvent.request.userAttributes['email'];
-str = cognitoUserPoolEvent.request.validationData!['k1'];
-strOrUndefined = cognitoUserPoolEvent.request.codeParameter;
-strOrUndefined = cognitoUserPoolEvent.request.linkParameter;
-strOrUndefined = cognitoUserPoolEvent.request.usernameParameter;
-boolOrUndefined = cognitoUserPoolEvent.request.newDeviceUsed;
-cognitoUserPoolEvent.request.session![0].challengeName === 'CUSTOM_CHALLENGE';
-cognitoUserPoolEvent.request.session![0].challengeName === 'PASSWORD_VERIFIER';
-cognitoUserPoolEvent.request.session![0].challengeName === 'SMS_MFA';
-cognitoUserPoolEvent.request.session![0].challengeName === 'DEVICE_SRP_AUTH';
-cognitoUserPoolEvent.request.session![0].challengeName === 'DEVICE_PASSWORD_VERIFIER';
-cognitoUserPoolEvent.request.session![0].challengeName === 'ADMIN_NO_SRP_AUTH';
-bool = cognitoUserPoolEvent.request.session![0].challengeResult;
-strOrUndefined = cognitoUserPoolEvent.request.session![0].challengeMetadata;
-strOrUndefined = cognitoUserPoolEvent.request.challengeName;
-str = cognitoUserPoolEvent.request.privateChallengeParameters!['answer'];
-str = cognitoUserPoolEvent.request.challengeAnswer!;
-strOrUndefined = cognitoUserPoolEvent.request.password;
-boolOrUndefined = cognitoUserPoolEvent.response.answerCorrect;
-strOrUndefined = cognitoUserPoolEvent.response.smsMessage;
-strOrUndefined = cognitoUserPoolEvent.response.emailMessage;
-strOrUndefined = cognitoUserPoolEvent.response.emailSubject;
-strOrUndefined = cognitoUserPoolEvent.response.challengeName;
-boolOrUndefined = cognitoUserPoolEvent.response.issueTokens;
-boolOrUndefined = cognitoUserPoolEvent.response.failAuthentication;
-str = cognitoUserPoolEvent.response.publicChallengeParameters!['captchaUrl'];
-str = cognitoUserPoolEvent.response.privateChallengeParameters!['answer'];
-strOrUndefined = cognitoUserPoolEvent.response.challengeMetadata;
-boolOrUndefined = cognitoUserPoolEvent.response.answerCorrect;
-str = cognitoUserPoolEvent.response.userAttributes!['username'];
-cognitoUserPoolEvent.response.finalUserStatus === 'CONFIRMED';
-cognitoUserPoolEvent.response.finalUserStatus === 'RESET_REQUIRED';
-cognitoUserPoolEvent.response.messageAction === 'SUPPRESS';
-cognitoUserPoolEvent.response.desiredDeliveryMediums === ['EMAIL'];
-cognitoUserPoolEvent.response.desiredDeliveryMediums === ['SMS'];
-cognitoUserPoolEvent.response.desiredDeliveryMediums === ['SMS', 'EMAIL'];
-boolOrUndefined = cognitoUserPoolEvent.response.forceAliasCreation;
-// From AWS examples
-cognitoUserPoolEvent.response = {
-    claimsOverrideDetails: {
-        claimsToAddOrOverride: {
-            attribute_key2: 'attribute_value2',
-            attribute_key: 'attribute_value',
-        },
-        claimsToSuppress: ['email'],
-    },
-};
-cognitoUserPoolEvent.response = {
-    claimsOverrideDetails: {
-        claimsToAddOrOverride: {
-            attribute_key2: 'attribute_value2',
-            attribute_key: 'attribute_value',
-        },
-        claimsToSuppress: ['email'],
-        groupOverrideDetails: {
-            groupsToOverride: ['group-A', 'group-B', 'group-C'],
-            iamRolesToOverride: [
-                'arn:aws:iam::XXXXXXXXXXXX:role/sns_callerA',
-                'arn:aws:iam::XXXXXXXXX:role/sns_callerB',
-                'arn:aws:iam::XXXXXXXXXX:role/sns_callerC',
-            ],
-            preferredRole: 'arn:aws:iam::XXXXXXXXXXX:role/sns_caller',
-        },
-    },
-};
-cognitoUserPoolEvent.response.claimsOverrideDetails!.groupOverrideDetails = null;
-
-// CloudFormation Custom Resource
-switch (cloudformationCustomResourceEvent.RequestType) {
-    case 'Create':
-        str = cloudformationCustomResourceEvent.LogicalResourceId;
-        str = cloudformationCustomResourceEvent.RequestId;
-        anyObj = cloudformationCustomResourceEvent.ResourceProperties;
-        str = cloudformationCustomResourceEvent.ResourceProperties.ServiceToken;
-        str = cloudformationCustomResourceEvent.ResourceType;
-        str = cloudformationCustomResourceEvent.ResponseURL;
-        str = cloudformationCustomResourceEvent.ServiceToken;
-        str = cloudformationCustomResourceEvent.StackId;
-        break;
-    case 'Update':
-        anyObj = cloudformationCustomResourceEvent.OldResourceProperties;
-        break;
-    case 'Delete':
-        str = cloudformationCustomResourceEvent.PhysicalResourceId;
-        break;
-}
-anyObj = cloudformationCustomResourceResponse.Data;
-str = cloudformationCustomResourceResponse.LogicalResourceId;
-str = cloudformationCustomResourceResponse.PhysicalResourceId;
-strOrUndefined = cloudformationCustomResourceResponse.Reason;
-str = cloudformationCustomResourceResponse.RequestId;
-str = cloudformationCustomResourceResponse.StackId;
-str = cloudformationCustomResourceResponse.Status;
-boolOrUndefined = cloudformationCustomResourceResponse.NoEcho;
-
-/* ScheduledEvent */
-str = scheduledEvent.account;
-anyObj = scheduledEvent.detail;
-str = scheduledEvent.id;
-str = scheduledEvent.region;
-str = scheduledEvent.resources[0];
-str = scheduledEvent.source;
-str = scheduledEvent.time;
 
 /* Context */
 bool = context.callbackWaitsForEmptyEventLoop;
@@ -550,23 +38,9 @@ str = context.logStreamName;
 identityOrUndefined = context.identity;
 clientCtxOrUndefined = context.clientContext;
 
-/* CognitoIdentity */
 str = identity.cognitoIdentityId;
 str = identity.cognitoIdentityPoolId;
 
-/* CloudWatch Logs */
-str = cloudwatchLogsEvent.awslogs.data;
-
-str = cloudwatchLogsDecodedData.owner;
-str = cloudwatchLogsDecodedData.logGroup;
-str = cloudwatchLogsDecodedData.logStream;
-str = cloudwatchLogsDecodedData.subscriptionFilters[0];
-str = cloudwatchLogsDecodedData.messageType;
-str = cloudwatchLogsDecodedData.logEvents[0].id;
-num = cloudwatchLogsDecodedData.logEvents[0].timestamp;
-str = cloudwatchLogsDecodedData.logEvents[0].message;
-str = cloudwatchLogsDecodedData.logEvents[0].extractedFields!['example'];
-
 /* ClientContext */
 clientContextClient = clientCtx.client;
 anyObj = clientCtx.Custom;
@@ -586,304 +60,35 @@ str = clientContextClient.appVersionCode;
 str = clientContextClient.appVersionName;
 str = clientContextClient.installationId;
 
-/* Callback */
-function callback(cb: AWSLambda.Callback) {
-    cb();
-    cb(null);
-    cb(error);
-    cb(str); // https://docs.aws.amazon.com/apigateway/latest/developerguide/handle-errors-in-lambda-integration.html
-    cb(null, anyObj);
-    cb(null, bool);
-    cb(null, str);
-    cb(null, num);
-}
+declare const untypedCallback: AWSLambda.Callback;
+untypedCallback();
+untypedCallback(undefined);
+untypedCallback(null);
+untypedCallback(error);
+untypedCallback(str); // https://docs.aws.amazon.com/apigateway/latest/developerguide/handle-errors-in-lambda-integration.html
+untypedCallback(null, anyObj);
+untypedCallback(undefined, bool);
+untypedCallback(null, bool);
+untypedCallback(null, str);
+untypedCallback(null, num);
+untypedCallback(null, { foo: 123 });
+untypedCallback(null, { bar: 123 });
+// $ExpectError
+untypedCallback(null, anyObj, anyObj);
 
-/* Proxy Callback */
-function proxyCallback(cb: AWSLambda.ProxyCallback) {
-    cb();
-    cb(null);
-    cb(error);
-    cb(null, proxyResult);
-}
-
-/* CustomAuthorizerCallback */
-function customAuthorizerCallback(cb: AWSLambda.CustomAuthorizerCallback) {
-    cb();
-    cb(null);
-    cb(error);
-    cb(null, authResponse);
-}
-
-/* CodePipeline events https://docs.aws.amazon.com/codepipeline/latest/userguide/actions-invoke-lambda-function.html#actions-invoke-lambda-function-json-event-example */
-const CodePipelineEvent: AWSLambda.CodePipelineEvent = {
-    'CodePipeline.job': {
-        id: '11111111-abcd-1111-abcd-111111abcdef',
-        accountId: '111111111111',
-        data: {
-            actionConfiguration: {
-                configuration: {
-                    FunctionName: 'MyLambdaFunctionForAWSCodePipeline',
-                    UserParameters: 'some-input-such-as-a-URL',
-                },
-            },
-            inputArtifacts: [
-                {
-                    location: {
-                        s3Location: {
-                            bucketName:
-                                'the name of the bucket configured as the pipeline artifact store in Amazon S3, for example codepipeline-us-east-2-1234567890',
-                            objectKey: 'the name of the application, for example CodePipelineDemoApplication.zip',
-                        },
-                        type: 'S3',
-                    },
-                    revision: null,
-                    name: 'ArtifactName',
-                },
-            ],
-            outputArtifacts: [],
-            artifactCredentials: {
-                secretAccessKey: 'wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY',
-                sessionToken: `MIICiTCCAfICCQD6m7oRw0uXOjANBgkqhkiG9w
- 0BAQUFADCBiDELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAldBMRAwDgYDVQQHEwdTZ
- WF0dGxlMQ8wDQYDVQQKEwZBbWF6b24xFDASBgNVBAsTC0lBTSBDb25zb2xlMRIw
- EAYDVQQDEwlUZXN0Q2lsYWMxHzAdBgkqhkiG9w0BCQEWEG5vb25lQGFtYXpvbi5
- jb20wHhcNMTEwNDI1MjA0NTIxWhcNMTIwNDI0MjA0NTIxWjCBiDELMAkGA1UEBh
- MCVVMxCzAJBgNVBAgTAldBMRAwDgYDVQQHEwdTZWF0dGxlMQ8wDQYDVQQKEwZBb
- WF6b24xFDASBgNVBAsTC0lBTSBDb25zb2xlMRIwEAYDVQQDEwlUZXN0Q2lsYWMx
- HzAdBgkqhkiG9w0BCQEWEG5vb25lQGFtYXpvbi5jb20wgZ8wDQYJKoZIhvcNAQE
- BBQADgY0AMIGJAoGBAMaK0dn+a4GmWIWJ21uUSfwfEvySWtC2XADZ4nB+BLYgVI
- k60CpiwsZ3G93vUEIO3IyNoH/f0wYK8m9TrDHudUZg3qX4waLG5M43q7Wgc/MbQ
- ITxOUSQv7c7ugFFDzQGBzZswY6786m86gpEIbb3OhjZnzcvQAaRHhdlQWIMm2nr
- AgMBAAEwDQYJKoZIhvcNAQEFBQADgYEAtCu4nUhVVxYUntneD9+h8Mg9q6q+auN
- KyExzyLwaxlAoo7TJHidbtS4J5iNmZgXL0FkbFFBjvSfpJIlJ00zbhNYS5f6Guo
- EDmFJl0ZxBHjJnyp378OD8uTs7fLvjx79LjSTbNYiytVbZPQUQ5Yaxu2jXnimvw
- 3rrszlaEXAMPLE=`,
-                accessKeyId: 'AKIAIOSFODNN7EXAMPLE',
-            },
-            continuationToken: 'A continuation token if continuing job',
-        },
-    },
-};
-
-CodePipelineEvent['CodePipeline.job'].data.encryptionKey = { type: 'KMS', id: 'key' };
-
-/* CodePipeline CloudWatch Events
- * see https://docs.aws.amazon.com/codepipeline/latest/userguide/detect-state-changes-cloudwatch-events.html
- * Their documentation says that detail.version is a string, but it is actually an integer
- */
-const CodePipelineCloudWatchEvent: AWSLambda.CodePipelineCloudWatchEvent = {
-    version: '0',
-    id: 'event_Id',
-    'detail-type': 'CodePipeline Pipeline Execution State Change',
-    source: 'aws.codepipeline',
-    account: 'Pipeline_Account',
-    time: 'TimeStamp',
-    region: 'us-east-1',
-    resources: ['arn:aws:codepipeline:us-east-1:account_ID:myPipeline'],
-    detail: {
-        pipeline: 'myPipeline',
-        version: 1,
-        state: 'STARTED',
-        'execution-id': 'execution_Id',
-    },
-};
-
-/* CloudFront events, see http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html */
-const CloudFrontRequestWithCustomOriginEvent: AWSLambda.CloudFrontRequestEvent = {
-    Records: [
-        {
-            cf: {
-                config: {
-                    distributionDomainName: 'd123.cloudfront.net',
-                    distributionId: 'EDFDVBD6EXAMPLE',
-                    eventType: 'viewer-request',
-                    requestId: 'MRVMF7KydIvxMWfJIglgwHQwZsbG2IhRJ07sn9AkKUFSHS9EXAMPLE==',
-                },
-                request: {
-                    body: {
-                        action: 'read-only',
-                        data: 'eyJ1c2VybmFtZSI6IkxhbWJkYUBFZGdlIiwiY29tbWVudCI6IlRoaXMgaXMgcmVxdWVzdCBib2R5In0=',
-                        encoding: 'base64',
-                        inputTruncated: false,
-                    },
-                    clientIp: '2001:0db8:85a3:0:0:8a2e:0370:7334',
-                    querystring: 'size=large',
-                    uri: '/picture.jpg',
-                    method: 'GET',
-                    headers: {
-                        host: [
-                            {
-                                key: 'Host',
-                                value: 'd111111abcdef8.cloudfront.net',
-                            },
-                        ],
-                        'user-agent': [
-                            {
-                                key: 'User-Agent',
-                                value: 'curl/7.51.0',
-                            },
-                        ],
-                    },
-                    origin: {
-                        custom: {
-                            customHeaders: {
-                                'my-origin-custom-header': [
-                                    {
-                                        key: 'My-Origin-Custom-Header',
-                                        value: 'Test',
-                                    },
-                                ],
-                            },
-                            domainName: 'example.com',
-                            keepaliveTimeout: 5,
-                            path: '/custom_path',
-                            port: 443,
-                            protocol: 'https',
-                            readTimeout: 5,
-                            sslProtocols: ['TLSv1', 'TLSv1.1'],
-                        },
-                    },
-                },
-            },
-        },
-    ],
-};
-
-const CloudFrontRequestWithS3OriginEvent: AWSLambda.CloudFrontRequestEvent = {
-    Records: [
-        {
-            cf: {
-                config: {
-                    distributionDomainName: 'd123.cloudfront.net',
-                    distributionId: 'EDFDVBD6EXAMPLE',
-                    eventType: 'viewer-request',
-                    requestId: 'MRVMF7KydIvxMWfJIglgwHQwZsbG2IhRJ07sn9AkKUFSHS9EXAMPLE==',
-                },
-                request: {
-                    body: {
-                        action: 'read-only',
-                        data: 'eyJ1c2VybmFtZSI6IkxhbWJkYUBFZGdlIiwiY29tbWVudCI6IlRoaXMgaXMgcmVxdWVzdCBib2R5In0=',
-                        encoding: 'base64',
-                        inputTruncated: false,
-                    },
-                    clientIp: '2001:0db8:85a3:0:0:8a2e:0370:7334',
-                    querystring: 'size=large',
-                    uri: '/picture.jpg',
-                    method: 'GET',
-                    headers: {
-                        host: [
-                            {
-                                key: 'Host',
-                                value: 'd111111abcdef8.cloudfront.net',
-                            },
-                        ],
-                        'user-agent': [
-                            {
-                                key: 'User-Agent',
-                                value: 'curl/7.51.0',
-                            },
-                        ],
-                    },
-                    origin: {
-                        s3: {
-                            authMethod: 'origin-access-identity',
-                            customHeaders: {
-                                'my-origin-custom-header': [
-                                    {
-                                        key: 'My-Origin-Custom-Header',
-                                        value: 'Test',
-                                    },
-                                ],
-                            },
-                            domainName: 'my-bucket.s3.amazonaws.com',
-                            path: '/s3_path',
-                            region: 'us-east-1',
-                        },
-                    },
-                },
-            },
-        },
-    ],
-};
-
-const CloudFrontResponseEvent: AWSLambda.CloudFrontResponseEvent = {
-    Records: [
-        {
-            cf: {
-                config: {
-                    distributionDomainName: 'd123.cloudfront.net',
-                    distributionId: 'EDFDVBD6EXAMPLE',
-                    eventType: 'viewer-response',
-                    requestId: 'xGN7KWpVEmB9Dp7ctcVFQC4E-nrcOcEKS3QyAez--06dV7TEXAMPLE==',
-                },
-                request: {
-                    clientIp: '2001:0db8:85a3:0:0:8a2e:0370:7334',
-                    method: 'GET',
-                    uri: '/picture.jpg',
-                    querystring: 'size=large',
-                    headers: {
-                        host: [
-                            {
-                                key: 'Host',
-                                value: 'd111111abcdef8.cloudfront.net',
-                            },
-                        ],
-                        'user-agent': [
-                            {
-                                key: 'User-Agent',
-                                value: 'curl/7.18.1',
-                            },
-                        ],
-                    },
-                },
-                response: {
-                    status: '200',
-                    statusDescription: 'OK',
-                    headers: {
-                        server: [
-                            {
-                                key: 'Server',
-                                value: 'MyCustomOrigin',
-                            },
-                        ],
-                        'set-cookie': [
-                            {
-                                key: 'Set-Cookie',
-                                value: 'theme=light',
-                            },
-                            {
-                                key: 'Set-Cookie',
-                                value: 'sessionToken=abc123; Expires=Wed, 09 Jun 2021 10:18:14 GMT',
-                            },
-                        ],
-                    },
-                },
-            },
-        },
-    ],
-};
-
-/* Kinesis Data Stream Events */
-declare let kinesisStreamEvent: AWSLambda.KinesisStreamEvent;
-declare let kinesisStreamRecord: AWSLambda.KinesisStreamRecord;
-declare let kinesisStreamRecordPayload: AWSLambda.KinesisStreamRecordPayload;
-
-kinesisStreamRecord = kinesisStreamEvent.Records[0];
-
-str = kinesisStreamRecord.awsRegion;
-str = kinesisStreamRecord.eventID;
-str = kinesisStreamRecord.eventName;
-str = kinesisStreamRecord.eventSource;
-str = kinesisStreamRecord.eventSourceARN;
-str = kinesisStreamRecord.eventVersion;
-str = kinesisStreamRecord.invokeIdentityArn;
-kinesisStreamRecordPayload = kinesisStreamRecord.kinesis;
-
-num = kinesisStreamRecordPayload.approximateArrivalTimestamp;
-str = kinesisStreamRecordPayload.data;
-str = kinesisStreamRecordPayload.kinesisSchemaVersion;
-str = kinesisStreamRecordPayload.partitionKey;
-str = kinesisStreamRecordPayload.sequenceNumber;
+interface TestResult { foo: number; }
+declare const typedCallback: AWSLambda.Callback<TestResult>;
+typedCallback();
+typedCallback(undefined);
+typedCallback(null);
+typedCallback(error);
+typedCallback(str); // https://docs.aws.amazon.com/apigateway/latest/developerguide/handle-errors-in-lambda-integration.html
+typedCallback(null, anyObj);
+typedCallback(null, { foo: 123 });
+// $ExpectError
+typedCallback(null, str);
+// $ExpectError
+typedCallback(null, { bar: 123 });
 
 /* Compatibility functions */
 context.done();
@@ -895,231 +100,6 @@ context.succeed(str, anyObj);
 context.fail(error);
 context.fail(str);
 
-/* Handler */
-const handler: AWSLambda.Handler = (event: any, context: AWSLambda.Context, cb: AWSLambda.Callback) => {};
-
-/* In node8.10 runtime, handlers may return a promise for the result value, so existing async
- * handlers that return Promise<void> before calling the callback will now have a `null` result.
- * Be safe and make that badly typed with a major verson bump to 8.10 so users expect the breaking change,
- * since the upgrade effort should be pretty low in most cases, and it points them at a nicer solution.
- */
-// $ExpectError
-const legacyAsyncHandler: AWSLambda.APIGatewayProxyHandler = async (
-    event: AWSLambda.APIGatewayProxyEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<AWSLambda.APIGatewayProxyResult>,
-) => {
-    cb(null, { statusCode: 200, body: 'No longer valid' });
-};
-
-const node8AsyncHandler: AWSLambda.APIGatewayProxyHandler = async (
-    event: AWSLambda.APIGatewayProxyEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<AWSLambda.APIGatewayProxyResult>,
-) => {
-    return { statusCode: 200, body: 'Is now valid!' };
-};
-
-const inferredHandler: AWSLambda.S3Handler = (event, context, cb) => {
-    // $ExpectType S3Event
-    event;
-    str = event.Records[0].eventName;
-    // $ExpectType Context
-    context;
-    str = context.functionName;
-    // $ExpectType Callback<void>
-    cb;
-    cb();
-    cb(null);
-    cb(new Error());
-    // $ExpectError
-    cb(null, {});
-};
-
-// Test using default Callback type still works.
-const defaultCallbackHandler: AWSLambda.APIGatewayProxyHandler = (
-    event: AWSLambda.APIGatewayEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback,
-) => {};
-
-const albSyncHandler: AWSLambda.ALBHandler = (
-    event: AWSLambda.ALBEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.ALBCallback,
-) => {
-    cb(null, {
-        statusCode: 200,
-        statusDescription: '200 OK',
-        headers: {},
-        body: '',
-        isBase64Encoded: false,
-    });
-};
-const albAsyncHandler: AWSLambda.ALBHandler = async (
-    event: AWSLambda.ALBEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.ALBCallback,
-) => {
-    return {
-        statusCode: 200,
-        statusDescription: '200 OK',
-        headers: {},
-        body: '',
-        isBase64Encoded: false,
-    };
-};
-
-// Specific types
-let s3Handler: AWSLambda.S3Handler = (
-    event: AWSLambda.S3Event,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-// Test old name
-const s3CreateHandler: AWSLambda.S3Handler = (
-    event: AWSLambda.S3CreateEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-s3Handler = s3CreateHandler;
-
-const dynamoDBStreamHandler: AWSLambda.DynamoDBStreamHandler = (
-    event: AWSLambda.DynamoDBStreamEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-const snsHandler: AWSLambda.SNSHandler = (
-    event: AWSLambda.SNSEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-const cognitoUserPoolHandler: AWSLambda.CognitoUserPoolTriggerHandler = (
-    event: AWSLambda.CognitoUserPoolEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-const cloudFormationCustomResourceHandler: AWSLambda.CloudFormationCustomResourceHandler = (
-    event: AWSLambda.CloudFormationCustomResourceEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-const cloudWatchLogsHandler: AWSLambda.CloudWatchLogsHandler = (
-    event: AWSLambda.CloudWatchLogsEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-const scheduledHandler: AWSLambda.ScheduledHandler = (
-    event: AWSLambda.ScheduledEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-let apiGtwProxyHandler: AWSLambda.APIGatewayProxyHandler = (
-    event: AWSLambda.APIGatewayProxyEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.APIGatewayProxyCallback,
-) => {};
-// Test old names
-const proxyHandler: AWSLambda.ProxyHandler = (
-    event: AWSLambda.APIGatewayEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.ProxyCallback,
-) => {};
-apiGtwProxyHandler = proxyHandler;
-
-const codePipelineHandler: AWSLambda.CodePipelineHandler = (
-    event: AWSLambda.CodePipelineEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-const cloudFrontRequestHandler: AWSLambda.CloudFrontRequestHandler = (
-    event: AWSLambda.CloudFrontRequestEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.CloudFrontRequestCallback,
-) => {
-    event = CloudFrontRequestWithCustomOriginEvent;
-    // $ExpectType CloudFrontRequestEvent
-    event;
-    let request = event.Records[0].cf.request;
-
-    let s3Origin: AWSLambda.CloudFrontS3Origin = {
-        authMethod: 'none',
-        customHeaders: {},
-        domainName: 'example.com',
-        path: '/',
-        region: 'us-east-1',
-    };
-
-    if (request.origin && request.origin.custom) {
-        request.origin.custom.domainName;
-        request.origin.custom.domainName = 'example2.com';
-
-        // $ExpectError
-        s3Origin = request.origin.s3;
-
-        // $ExpectError
-        request.origin.s3.path = '/';
-    }
-
-    let customOrigin: AWSLambda.CloudFrontCustomOrigin = {
-        customHeaders: {},
-        domainName: 'example.com',
-        keepaliveTimeout: 60,
-        path: '/',
-        port: 80,
-        protocol: 'http',
-        readTimeout: 30,
-        sslProtocols: [],
-    };
-
-    event = CloudFrontRequestWithS3OriginEvent;
-    // $ExpectType CloudFrontRequestEvent
-    event;
-    request = event.Records[0].cf.request;
-    if (request.origin && request.origin.s3) {
-        request.origin.s3.path;
-        request.origin.s3.path = '/new_path';
-
-        // $ExpectError
-        customOrigin = request.origin.custom;
-
-        // $ExpectError
-        request.origin.custom.path = '/';
-    }
-
-    cb();
-    cb(null);
-    cb(new Error(''));
-    cb(null, { clientIp: str, method: str, uri: str, querystring: str, headers: {} });
-    cb(null, { status: str });
-    // $ExpectError
-    cb(null, {});
-};
-
-const cloudFrontResponseHandler: AWSLambda.CloudFrontResponseHandler = (
-    event: AWSLambda.CloudFrontResponseEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.CloudFrontResponseCallback,
-) => {};
-
-const cloudFrontHeaders: AWSLambda.CloudFrontHeaders = {
-    'content-type': [{ value: 'text/plain' }],
-    'x-foo-bar': [{ key: 'X-Foo-Bar', value: 'example' }],
-};
-
-const customAuthorizerHandler: AWSLambda.CustomAuthorizerHandler = (
-    event: AWSLambda.CustomAuthorizerEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.CustomAuthorizerCallback,
-) => {};
-
 interface CustomEvent {
     eventString: string;
     eventBool: boolean;
@@ -1128,281 +108,89 @@ interface CustomResult {
     resultString: string;
     resultBool?: boolean;
 }
+type CustomHandler = AWSLambda.Handler<CustomEvent, CustomResult>;
 type CustomCallback = AWSLambda.Callback<CustomResult>;
-const customHandler: AWSLambda.Handler<CustomEvent, CustomResult> = (event, context, cb) => {
-    // $ExpectType CustomEvent
+
+// Untyped handlers should work
+const untypedAsyncHandler: AWSLambda.Handler = async (event, context, cb) => {
+    // $ExpectType any
     event;
-    str = event.eventString;
-    bool = event.eventBool;
     // $ExpectType Context
     context;
-    // $ExpectType Callback<CustomResult>
+    // $ExpectType Callback<any>
     cb;
-    cb(null, { resultString: str, resultBool: bool });
-    // $ExpectError
+    // Can still use callback
+    cb(null, { resultString: str });
+    if (bool) {
+        // Uncaught error
+        return { resultString: bool };
+    }
+    return { resultString: str };
+};
+
+const untypedCallbackHandler: AWSLambda.Handler = (event, context, cb) => {
+    // $ExpectType any
+    event;
+    // $ExpectType Context
+    context;
+    // $ExpectType Callback<any>
+    cb;
+    cb(null, { resultString: str });
+    // Uncaught error
     cb(null, { resultString: bool });
 };
 
-const kinesisStreamHandler: AWSLambda.KinesisStreamHandler = (
-    event: AWSLambda.KinesisStreamEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
+/* In node8.10 runtime, handlers may return a promise for the result value, so existing async
+ * handlers that return Promise<void> before calling the callback will now have a `null` result.
+ * Be safe and make that badly typed with a major verson bump to 8.10 so users expect the breaking change,
+ * since the upgrade effort should be pretty low in most cases, and it points them at a nicer solution.
+ */
 
-const SQSMessageHandler: AWSLambda.SQSHandler = (
-    event: AWSLambda.SQSEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {};
-
-// See https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-sqs
-const SQSEvent: AWSLambda.SQSEvent = {
-    Records: [
-        {
-            messageId: 'c80e8021-a70a-42c7-a470-796e1186f753',
-            receiptHandle: 'AQEBJQ+/u6NsnT5t8Q/VbVxgdUl4TMKZ5FqhksRdIQvLBhwNvADoBxYSOVeCBXdnS9P+',
-            body: '{"foo":"bar"}',
-            attributes: {
-                ApproximateReceiveCount: '3',
-                SentTimestamp: '1529104986221',
-                SenderId: '594035263019',
-                ApproximateFirstReceiveTimestamp: '1529104986230',
-            },
-            messageAttributes: {
-                testAttr: {
-                    stringValue: '100',
-                    binaryValue: 'base64Str',
-                    stringListValues: [],
-                    binaryListValues: [],
-                    dataType: 'Number',
-                },
-            },
-            md5OfBody: '9bb58f26192e4ba00f01e2e7b136bbd8',
-            eventSource: 'aws:sqs',
-            eventSourceARN: 'arn:aws:sqs:us-west-2:594035263019:NOTFIFOQUEUE',
-            awsRegion: 'us-west-2',
-        },
-    ],
+// Test we get error for unsafe old style
+// $ExpectError
+const unsafeAsyncHandler: CustomHandler = async (event, context, cb) => {
+    cb(null, { resultString: 'No longer valid' });
 };
 
-const SQSMessageLegacyAsyncHandler: AWSLambda.SQSHandler = async (
-    event: AWSLambda.SQSEvent,
-    context: AWSLambda.Context,
-    cb: AWSLambda.Callback<void>,
-) => {
-    // $ExpectType SQSEvent
+// Test safe old style still works
+const typedCallbackHandler: CustomHandler = (event, context, cb) => {
+    // $ExpectType CustomEvent
     event;
-    str = event.Records[0].messageId;
-    anyObj = event.Records[0].body;
+    str = event.eventString;
     // $ExpectType Context
     context;
     str = context.functionName;
-    // $ExpectType Callback<void>
+    // $ExpectType Callback<CustomResult>
     cb;
     cb();
     cb(null);
     cb(new Error());
+    // $ExpectError
+    cb(null, {});
+    cb(null, { resultString: str });
+    // $ExpectError
+    cb(null, { resultString: bool });
 };
 
-const SQSMessageNode8AsyncHandler: AWSLambda.SQSHandler = async (
-    event: AWSLambda.SQSEvent,
+// Test preferred new type
+const typedAsyncHandler: CustomHandler = async (event, context, cb) => {
+    // $ExpectType CustomEvent
+    event;
+    // $ExpectType Context
+    context;
+    // $ExpectType Callback<CustomResult>
+    cb;
+    // Can still use callback
+    cb(null, { resultString: str });
+    return { resultString: 'Is now valid!' };
+};
+
+// $ExpectError
+const badTypedAsyncHandler: CustomHandler = async (event, context, cb) => ({ resultString: bool });
+
+// Test using untyped Callback type still works.
+const mixedUntypedCallbackTypedHandler: CustomHandler = (
+    event: CustomEvent,
     context: AWSLambda.Context,
-) => {
-    // $ExpectType SQSEvent
-    event;
-    str = event.Records[0].messageId;
-    anyObj = event.Records[0].body;
-    strOrUndefined = event.Records[0].messageAttributes.testAttr.stringValue;
-    strOrUndefined = event.Records[0].messageAttributes.testAttr.binaryValue;
-    str = event.Records[0].messageAttributes.testAttr.dataType;
-
-    // $ExpectType Context
-    context;
-    str = context.functionName;
-    return;
-};
-
-const firehoseEventHandler: AWSLambda.FirehoseTransformationHandler = (
-    event: AWSLambda.FirehoseTransformationEvent,
-    context: AWSLambda.Context,
-    callback: AWSLambda.FirehoseTransformationCallback,
-) => {
-    // $ExpectType FirehoseTransformationEvent
-    event;
-    str = event.records[0].recordId;
-
-    // $ExpectType Context
-    context;
-    str = context.functionName;
-    callback(null, {
-        records: [
-            {
-                recordId: event.records[0].recordId,
-                result: 'Ok' as AWSLambda.FirehoseRecordTransformationStatus,
-                data: 'eyJmb28iOiJiYXIifQ==',
-            },
-        ],
-    });
-};
-
-declare let lexEvent: AWSLambda.LexEvent;
-lexEvent = {
-    currentIntent: {
-        name: 'intent-name',
-        slots: {
-            slot1: null,
-            slot2: 'value2',
-        },
-        slotDetails: {
-            slot1: {
-                resolutions: [{ value: 'value1' }],
-                originalValue: 'originalValue',
-            },
-        },
-        confirmationStatus: 'None',
-    },
-    bot: {
-        name: 'bot name',
-        alias: 'bot alias',
-        version: 'bot version',
-    },
-    userId: 'User ID specified in the POST request to Amazon Lex.',
-    inputTranscript: 'Text used to process the request',
-    invocationSource: 'FulfillmentCodeHook',
-    outputDialogMode: 'Text',
-    messageVersion: '1.0',
-    sessionAttributes: {
-        key1: 'value1',
-        key2: 'value2',
-    },
-    requestAttributes: {
-        key1: 'value1',
-        key2: 'value2',
-    },
-};
-
-declare let lexResult: AWSLambda.LexResult;
-declare let lexDialogAction: AWSLambda.LexDialogAction;
-declare let lexDialogActionBase: AWSLambda.LexDialogActionBase;
-declare let lexDialogActionClose: AWSLambda.LexDialogActionClose;
-declare let lexDialogActionConfirmIntent: AWSLambda.LexDialogActionConfirmIntent;
-declare let lexDialogActionDelegate: AWSLambda.LexDialogActionDelegate;
-declare let lexDialogActionElicitIntent: AWSLambda.LexDialogActionElicitIntent;
-declare let lexDialogActionElicitSlot: AWSLambda.LexDialogActionElicitSlot;
-declare let lexGenericAttachment: AWSLambda.LexGenericAttachment;
-
-lexResult = {
-    sessionAttributes: {
-        attrib1: 'Value One',
-    },
-    dialogAction: {
-        type: 'Close',
-        fulfillmentState: 'Failed',
-    },
-};
-
-str = lexGenericAttachment.title;
-str = lexGenericAttachment.subTitle;
-str = lexGenericAttachment.imageUrl;
-str = lexGenericAttachment.attachmentLinkUrl;
-str = lexGenericAttachment.buttons[0].text;
-str = lexGenericAttachment.buttons[0].value;
-
-lexDialogAction.type === 'Close';
-lexDialogAction.type === 'ConfirmIntent';
-lexDialogAction.type === 'Delegate';
-lexDialogAction.type === 'ElicitIntent';
-lexDialogAction.type === 'ElicitSlot';
-
-lexDialogActionBase.message!.contentType === 'CustomPayload';
-lexDialogActionBase.message!.contentType === 'PlainText';
-lexDialogActionBase.message!.contentType === 'SSML';
-str = lexDialogActionBase.message!.content;
-num = lexDialogActionBase.responseCard!.version;
-lexDialogActionBase.responseCard!.contentType === 'application/vnd.amazonaws.card.generic';
-// $ExpectType LexGenericAttachment
-lexDialogActionBase.responseCard!.genericAttachments[0];
-
-lexDialogActionClose.type === 'Close';
-lexDialogActionClose.fulfillmentState === 'Failed';
-lexDialogActionClose.fulfillmentState === 'Fulfilled';
-
-lexDialogActionConfirmIntent.type === 'ConfirmIntent';
-str = lexDialogActionConfirmIntent.intentName;
-strOrNull = lexDialogActionConfirmIntent.slots['example'];
-
-lexDialogActionDelegate.type === 'Delegate';
-strOrNull = lexDialogActionDelegate.slots['example'];
-
-lexDialogActionElicitIntent.type === 'ElicitIntent';
-lexDialogActionElicitSlot.type === 'ElicitSlot';
-strOrNull = lexDialogActionElicitSlot.slots['example'];
-str = lexDialogActionElicitSlot.slotToElicit;
-str = lexDialogActionElicitSlot.intentName;
-
-const lexEventHandler: AWSLambda.LexHandler = async (event: AWSLambda.LexEvent, context: AWSLambda.Context) => {
-    // $ExpectType LexEvent
-    event;
-
-    // $ExpectType Context
-    context;
-    str = context.functionName;
-    return lexResult;
-};
-
-/**
- * S3 Batch Operations event
- * https://docs.aws.amazon.com/AmazonS3/latest/dev/batch-ops-invoke-lambda.html
- */
-const S3BatchEvent: AWSLambda.S3BatchEvent = {
-    invocationSchemaVersion: '1.0',
-    invocationId: 'foo_invocation_id',
-    job: { id: 'foo_job_id' },
-    tasks: [
-        {
-            taskId: '11111',
-            s3Key: 'example.json',
-            s3BucketArn: 'arn:aws:s3:::foo-bucket',
-            s3VersionId: null,
-        },
-        {
-            taskId: '11111',
-            s3Key: 'example.json',
-            s3BucketArn: 'arn:aws:s3:::foo-bucket',
-            s3VersionId: 'asdf',
-        },
-    ],
-};
-
-const S3BatchResult: AWSLambda.S3BatchResult = {
-    invocationSchemaVersion: '1.0',
-    treatMissingKeysAs: 'PermanentFailure',
-    invocationId: 'foo_invocation_id',
-    results: [
-        {
-            taskId: '11111',
-            resultCode: 'Succeeded',
-            resultString: 'foo',
-        },
-        {
-            taskId: '22222',
-            resultCode: 'TemporaryFailure',
-            resultString: 'Error: failure',
-        },
-        {
-            taskId: '33333',
-            resultCode: 'PermanentFailure',
-            resultString: 'Error: failure',
-        },
-    ],
-};
-
-const S3BatchHandler: AWSLambda.S3BatchHandler = async (event: AWSLambda.S3BatchEvent, context: AWSLambda.Context) => {
-    // $ExpectType S3BatchEvent
-    event;
-
-    // $ExpectType Context
-    context;
-    str = context.functionName;
-    return S3BatchResult;
-};
+    cb: AWSLambda.Callback,
+) => {};
diff --git a/types/aws-lambda/common/api-gateway.d.ts b/types/aws-lambda/common/api-gateway.d.ts
new file mode 100644
index 0000000000..f031f4c74a
--- /dev/null
+++ b/types/aws-lambda/common/api-gateway.d.ts
@@ -0,0 +1,46 @@
+// Used by both APIGatewayPraxyEvent and APIGatewayAuthorizerEvent
+export interface APIGatewayEventRequestContext {
+    accountId: string;
+    apiId: string;
+    authorizer?: AuthResponseContext | null;
+    connectedAt?: number;
+    connectionId?: string;
+    domainName?: string;
+    domainPrefix?: string;
+    eventType?: string;
+    extendedRequestId?: string;
+    httpMethod: string;
+    identity: {
+        accessKey: string | null;
+        accountId: string | null;
+        apiKey: string | null;
+        apiKeyId: string | null;
+        caller: string | null;
+        cognitoAuthenticationProvider: string | null;
+        cognitoAuthenticationType: string | null;
+        cognitoIdentityId: string | null;
+        cognitoIdentityPoolId: string | null;
+        principalOrgId: string | null;
+        sourceIp: string;
+        user: string | null;
+        userAgent: string | null;
+        userArn: string | null;
+    };
+    messageDirection?: string;
+    messageId?: string | null;
+    path: string;
+    stage: string;
+    requestId: string;
+    requestTime?: string;
+    requestTimeEpoch: number;
+    resourceId: string;
+    resourcePath: string;
+    routeKey?: string;
+}
+
+/**
+ * http://docs.aws.amazon.com/apigateway/latest/developerguide/use-custom-authorizer.html#api-gateway-custom-authorizer-output
+ */
+export interface AuthResponseContext {
+    [name: string]: any;
+}
diff --git a/types/aws-lambda/common/cloudfront.d.ts b/types/aws-lambda/common/cloudfront.d.ts
new file mode 100644
index 0000000000..f0ebbae8f5
--- /dev/null
+++ b/types/aws-lambda/common/cloudfront.d.ts
@@ -0,0 +1,79 @@
+/**
+ * CloudFront events
+ * http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html
+ * Bear in mind that the "example" event structure in the page above includes
+ * both an S3 and a Custom origin, which is not strictly allowed. Only one
+ * of these per event may be present.
+ */
+export interface CloudFrontHeaders {
+    [name: string]: Array<{
+        key?: string;
+        value: string;
+    }>;
+}
+
+export type CloudFrontOrigin =
+    | { s3: CloudFrontS3Origin; custom?: never }
+    | { custom: CloudFrontCustomOrigin; s3?: never };
+
+export interface CloudFrontCustomOrigin {
+    customHeaders: CloudFrontHeaders;
+    domainName: string;
+    keepaliveTimeout: number;
+    path: string;
+    port: number;
+    protocol: 'http' | 'https';
+    readTimeout: number;
+    sslProtocols: string[];
+}
+
+export interface CloudFrontS3Origin {
+    authMethod: 'origin-access-identity' | 'none';
+    customHeaders: CloudFrontHeaders;
+    domainName: string;
+    path: string;
+    region: string;
+}
+
+export interface CloudFrontResponse {
+    status: string;
+    statusDescription: string;
+    headers: CloudFrontHeaders;
+}
+
+export interface CloudFrontRequest {
+    body?: {
+        action: 'read-only' | 'replace';
+        data: string;
+        encoding: 'base64' | 'text';
+        readonly inputTruncated: boolean;
+    };
+    readonly clientIp: string;
+    readonly method: string;
+    uri: string;
+    querystring: string;
+    headers: CloudFrontHeaders;
+    origin?: CloudFrontOrigin;
+}
+
+export interface CloudFrontEvent {
+    config: {
+        readonly distributionDomainName: string;
+        readonly distributionId: string;
+    } & (
+        | { readonly eventType: 'origin-request' | 'origin-response' }
+        | { readonly eventType: 'viewer-request' | 'viewer-response'; readonly requestId: string });
+}
+
+/**
+ * Generated HTTP response in viewer request event or origin request event
+ *
+ * https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-generating-http-responses-in-requests.html#lambda-generating-http-responses-object
+ */
+export interface CloudFrontResultResponse {
+    status: string;
+    statusDescription?: string;
+    headers?: CloudFrontHeaders;
+    bodyEncoding?: 'text' | 'base64';
+    body?: string;
+}
diff --git a/types/aws-lambda/hander.d.ts b/types/aws-lambda/hander.d.ts
new file mode 100644
index 0000000000..54c270a246
--- /dev/null
+++ b/types/aws-lambda/hander.d.ts
@@ -0,0 +1,171 @@
+/**
+ * The interface that AWS Lambda will invoke your handler with.
+ * There are more specialized types for many cases where AWS services
+ * invoke your lambda, but you can directly use this type for when you are invoking
+ * your lambda directly.
+ *
+ * See tme {@link http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-handler.html AWS documentation}
+ * for more information about the runtime behavior, and the
+ * {@link https://aws.amazon.com/blogs/compute/node-js-8-10-runtime-now-available-in-aws-lambda/ AWS Blog post}
+ * introducing the async handler behavior in the 8.10 runtime.
+ *
+ * @example <caption>Defining a custom handler type</caption>
+ * import { Handler } from 'aws-lambda'
+ *
+ * interface NameEvent {
+ *     fullName: string
+ * }
+ * interface NameResult {
+ *     firstName: string
+ *     middleNames: string
+ *     lastName: string
+ * }
+ * type PersonHandler = Handler<NameEvent, NameResult>
+ *
+ * export const handler: PersonHandler = async (event) => {
+ *   const names = event.fullName.split(' ')
+ *   const firstName = names.shift()
+ *   const lastName = names.pop()
+ *   return { firstName, middleNames: names, lastName }
+ * }
+ *
+ * @example <caption>Logs the contents of the event object and returns the location of the logs</caption>
+ * import { Handler } from 'aws-lambda'
+ *
+ * export const handler: Handler = async (event, context) => {
+ *   console.log("EVENT: \n" + JSON.stringify(event, null, 2))
+ *   return context.logStreamName
+ * }
+ *
+ * @example <caption>AWS SDK with Async Function and Promises</caption>
+ * import { Handler } from 'aws-lambda'
+ * import AWS from 'aws-sdk'
+ *
+ * const s3 = new AWS.S3()
+ *
+ * export const handler: Handler = async (event) => {
+ *   const response = await s3.listBuckets().promise()
+ *   return response?.Buckets.map((bucket) => bucket.Name)
+ * }
+ *
+ * @example <caption>HTTP Request with Callback</caption>
+ * import { Handler } from 'aws-lambda'
+ * import https from 'https'
+ *
+ * let url = "https://docs.aws.amazon.com/lambda/latest/dg/welcome.html"
+ *
+ * export const handler: Handler<void, number> = (event, context, callback) => {
+ *  https.get(url, (res) => {
+ *    callback(null, res.statusCode)
+ *  }).on('error', (e) => {
+ *    callback(Error(e))
+ *  })
+ * }
+ *
+ * @param event
+ *      Parsed JSON data in the lambda request payload. For an AWS service triggered
+ *      lambda this should be in the format of a type ending in Event, for example the
+ *      S3Handler receives an event of type S3Event.
+ * @param context
+ *      Runtime contextual information of the current invocation, for example the caller
+ *      identity, available memory and time remaining, legacy completion callbacks, and
+ *      a mutable property controlling when the lambda execution completes.
+ * @param callback
+ *      NodeJS-style completion callback that the AWS Lambda runtime will provide that can
+ *      be used to provide the lambda result payload value, or any execution error. Can
+ *      instead return a promise that resolves with the result payload value or rejects
+ *      with the execution error.
+ * @return
+ *      A promise that resolves with the lambda result payload value, or rejects with the
+ *      execution error. Note that if you implement your handler as an async function,
+ *      you will automatically return a promise that will resolve with a returned value,
+ *      or reject with a thrown value.
+ */
+export type Handler<TEvent = any, TResult = any> = (
+    event: TEvent,
+    context: Context,
+    callback: Callback<TResult>,
+) => void | Promise<TResult>;
+
+/**
+ * {@link Handler} context parameter.
+ * See {@link https://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-context.html AWS documentation}.
+ */
+export interface Context {
+    callbackWaitsForEmptyEventLoop: boolean;
+    functionName: string;
+    functionVersion: string;
+    invokedFunctionArn: string;
+    memoryLimitInMB: string;
+    awsRequestId: string;
+    logGroupName: string;
+    logStreamName: string;
+    identity?: CognitoIdentity;
+    clientContext?: ClientContext;
+
+    getRemainingTimeInMillis(): number;
+
+    // Functions for compatibility with earlier Node.js Runtime v0.10.42
+    // No longer documented, so they are deprecated, but they still work
+    // as of the 12.x runtime, so they are not removed from the types.
+
+    /** @deprecated Use handler callback or promise result */
+    done(error?: Error, result?: any): void;
+    /** @deprecated Use handler callback with first argument or reject a promise result */
+    fail(error: Error | string): void;
+    /** @deprecated Use handler callback with second argument or resolve a promise result */
+    succeed(messageOrObject: any): void;
+    // Unclear what behavior this is supposed to have, I couldn't find any still extant reference,
+    // and it behaves like the above, ignoring the object parameter.
+    /** @deprecated Use handler callback or promise result */
+    succeed(message: string, object: any): void;
+}
+
+export interface CognitoIdentity {
+    cognitoIdentityId: string;
+    cognitoIdentityPoolId: string;
+}
+
+export interface ClientContext {
+    client: ClientContextClient;
+    Custom?: any;
+    env: ClientContextEnv;
+}
+
+export interface ClientContextClient {
+    installationId: string;
+    appTitle: string;
+    appVersionName: string;
+    appVersionCode: string;
+    appPackageName: string;
+}
+
+export interface ClientContextEnv {
+    platformVersion: string;
+    platform: string;
+    make: string;
+    model: string;
+    locale: string;
+}
+
+/**
+ * NodeJS-style callback parameter for the {@link Handler} type.
+ * Can be used instead of returning a promise, see the
+ * {@link https://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-handler.html AWS documentation}
+ * for the handler programming model.
+ *
+ * @param error
+ *   Parameter to use to provide the error payload for a failed lambda execution.
+ *   See {@link https://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-mode-exceptions.html AWS documentation}
+ *   for error handling.
+ *   If an Error instance is passed, the error payload uses the `name` property as the `errorType`,
+ *   the `message` property as the `errorMessage`, and parses the `stack` property string into
+ *   the `trace` array.
+ *   For other values, the `errorType` is `typeof value`, the `errorMessage` is `String(value)`, and
+ *   `trace` is an empty array.
+ *
+ * @param result
+ *   Parameter to use to provide the result payload for a successful lambda execution.
+ *   Pass `null` or `undefined` for the `error` parameter to use this parameter.
+ */
+export type Callback<TResult = any> = (error?: Error | string | null, result?: TResult) => void;
diff --git a/types/aws-lambda/index.d.ts b/types/aws-lambda/index.d.ts
index dc0262f046..58a9c7379d 100644
--- a/types/aws-lambda/index.d.ts
+++ b/types/aws-lambda/index.d.ts
@@ -1,8 +1,8 @@
 // Type definitions for AWS Lambda 8.10
 // Project: http://docs.aws.amazon.com/lambda
-// Definitions by: James Darbyshire <https://github.com/darbio/aws-lambda-typescript>
+// Definitions by: James Darbyshire <https://github.com/darbio>
 //                 Michael Skarum <https://github.com/skarum>
-//                 Stef Heyenrath <https://github.com/StefH/DefinitelyTyped>
+//                 Stef Heyenrath <https://github.com/StefH>
 //                 Toby Hede <https://github.com/tobyhede>
 //                 Rich Buggy <https://github.com/buggy>
 //                 Yoriki Yamaguchi <https://github.com/y13i>
@@ -36,1170 +36,40 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 
-// API Gateway "event" request context
-export interface APIGatewayEventRequestContext {
-    accountId: string;
-    apiId: string;
-    authorizer?: AuthResponseContext | null;
-    connectedAt?: number;
-    connectionId?: string;
-    domainName?: string;
-    domainPrefix?: string;
-    eventType?: string;
-    extendedRequestId?: string;
-    httpMethod: string;
-    identity: {
-        accessKey: string | null;
-        accountId: string | null;
-        apiKey: string | null;
-        apiKeyId: string | null;
-        caller: string | null;
-        cognitoAuthenticationProvider: string | null;
-        cognitoAuthenticationType: string | null;
-        cognitoIdentityId: string | null;
-        cognitoIdentityPoolId: string | null;
-        principalOrgId: string | null;
-        sourceIp: string;
-        user: string | null;
-        userAgent: string | null;
-        userArn: string | null;
-    };
-    messageDirection?: string;
-    messageId?: string | null;
-    path: string;
-    stage: string;
-    requestId: string;
-    requestTime?: string;
-    requestTimeEpoch: number;
-    resourceId: string;
-    resourcePath: string;
-    routeKey?: string;
-}
-
-// API Gateway "event"
-export interface APIGatewayProxyEvent {
-    body: string | null;
-    headers: { [name: string]: string };
-    multiValueHeaders: { [name: string]: string[] };
-    httpMethod: string;
-    isBase64Encoded: boolean;
-    path: string;
-    pathParameters: { [name: string]: string } | null;
-    queryStringParameters: { [name: string]: string } | null;
-    multiValueQueryStringParameters: { [name: string]: string[] } | null;
-    stageVariables: { [name: string]: string } | null;
-    requestContext: APIGatewayEventRequestContext;
-    resource: string;
-}
-export type APIGatewayEvent = APIGatewayProxyEvent; // Old name
-
-// https://docs.aws.amazon.com/elasticloadbalancing/latest/application/lambda-functions.html
-export interface ALBEventRequestContext {
-    elb: {
-        targetGroupArn: string;
-    };
-}
-export interface ALBEvent {
-    requestContext: ALBEventRequestContext;
-    httpMethod: string;
-    path: string;
-    queryStringParameters?: { [parameter: string]: string }; // URL encoded
-    headers?: { [header: string]: string };
-    multiValueQueryStringParameters?: { [parameter: string]: string[] }; // URL encoded
-    multiValueHeaders?: { [header: string]: string[] };
-    body: string | null;
-    isBase64Encoded: boolean;
-}
-
-// API Gateway CustomAuthorizer "event"
-export interface CustomAuthorizerEvent {
-    type: string;
-    methodArn: string;
-    authorizationToken?: string;
-    resource?: string;
-    path?: string;
-    httpMethod?: string;
-    headers?: { [name: string]: string };
-    multiValueHeaders?: { [name: string]: string[] };
-    pathParameters?: { [name: string]: string } | null;
-    queryStringParameters?: { [name: string]: string } | null;
-    multiValueQueryStringParameters?: { [name: string]: string[] } | null;
-    stageVariables?: { [name: string]: string };
-    requestContext?: APIGatewayEventRequestContext;
-    domainName?: string;
-    apiId?: string;
-}
-
-// Context
-// http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_streams_AttributeValue.html
-export interface AttributeValue {
-    B?: string;
-    BS?: string[];
-    BOOL?: boolean;
-    L?: AttributeValue[];
-    M?: { [id: string]: AttributeValue };
-    N?: string;
-    NS?: string[];
-    NULL?: boolean;
-    S?: string;
-    SS?: string[];
-}
-
-// Context
-// http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_streams_StreamRecord.html
-export interface StreamRecord {
-    ApproximateCreationDateTime?: number;
-    Keys?: { [key: string]: AttributeValue };
-    NewImage?: { [key: string]: AttributeValue };
-    OldImage?: { [key: string]: AttributeValue };
-    SequenceNumber?: string;
-    SizeBytes?: number;
-    StreamViewType?: 'KEYS_ONLY' | 'NEW_IMAGE' | 'OLD_IMAGE' | 'NEW_AND_OLD_IMAGES';
-}
-
-// Context
-// http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_streams_Record.html
-export interface DynamoDBRecord {
-    awsRegion?: string;
-    dynamodb?: StreamRecord;
-    eventID?: string;
-    eventName?: 'INSERT' | 'MODIFY' | 'REMOVE';
-    eventSource?: string;
-    eventSourceARN?: string;
-    eventVersion?: string;
-    userIdentity?: any;
-}
-
-// AWS Lambda Stream event
-// Context
-// http://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-ddb-update
-export interface DynamoDBStreamEvent {
-    Records: DynamoDBRecord[];
-}
-
-// SNS "event"
-export interface SNSMessageAttribute {
-    Type: string;
-    Value: string;
-}
-
-export interface SNSMessageAttributes {
-    [name: string]: SNSMessageAttribute;
-}
-
-export interface SNSMessage {
-    SignatureVersion: string;
-    Timestamp: string;
-    Signature: string;
-    SigningCertUrl: string;
-    MessageId: string;
-    Message: string;
-    MessageAttributes: SNSMessageAttributes;
-    Type: string;
-    UnsubscribeUrl: string;
-    TopicArn: string;
-    Subject: string;
-}
-
-export interface SNSEventRecord {
-    EventVersion: string;
-    EventSubscriptionArn: string;
-    EventSource: string;
-    Sns: SNSMessage;
-}
-
-export interface SNSEvent {
-    Records: SNSEventRecord[];
-}
-
-/**
- * S3Create event
- * https://docs.aws.amazon.com/AmazonS3/latest/dev/notification-content-structure.html
- */
-
-export interface S3EventRecordGlacierRestoreEventData {
-    lifecycleRestorationExpiryTime: string;
-    lifecycleRestoreStorageClass: string;
-}
-
-export interface S3EventRecordGlacierEventData {
-    restoreEventData: S3EventRecordGlacierRestoreEventData;
-}
-
-export interface S3EventRecord {
-    eventVersion: string;
-    eventSource: string;
-    awsRegion: string;
-    eventTime: string;
-    eventName: string;
-    userIdentity: {
-        principalId: string;
-    };
-    requestParameters: {
-        sourceIPAddress: string;
-    };
-    responseElements: {
-        'x-amz-request-id': string;
-        'x-amz-id-2': string;
-    };
-    s3: {
-        s3SchemaVersion: string;
-        configurationId: string;
-        bucket: {
-            name: string;
-            ownerIdentity: {
-                principalId: string;
-            };
-            arn: string;
-        };
-        object: {
-            key: string;
-            size: number;
-            eTag: string;
-            versionId?: string;
-            sequencer: string;
-        };
-    };
-    glacierEventData?: S3EventRecordGlacierEventData;
-}
-
-export interface S3Event {
-    Records: S3EventRecord[];
-}
-
-export type S3CreateEvent = S3Event; // old name
-
-/**
- * S3 Batch Operations event
- * https://docs.aws.amazon.com/AmazonS3/latest/dev/batch-ops-invoke-lambda.html
- */
-
-export interface S3BatchEvent {
-    invocationSchemaVersion: string;
-    invocationId: string;
-    job: S3BatchEventJob;
-    tasks: S3BatchEventTask[];
-}
-
-export interface S3BatchEventJob {
-    id: string;
-}
-
-export interface S3BatchEventTask {
-    taskId: string;
-    s3Key: string;
-    s3VersionId: string | null;
-    s3BucketArn: string;
-}
-
-export interface S3BatchResult {
-    invocationSchemaVersion: string;
-    treatMissingKeysAs: S3BatchResultResultCode;
-    invocationId: string;
-    results: S3BatchResultResult[];
-}
-
-export type S3BatchResultResultCode = 'Succeeded' | 'TemporaryFailure' | 'PermanentFailure';
-
-export interface S3BatchResultResult {
-    taskId: string;
-    resultCode: S3BatchResultResultCode;
-    resultString: string;
-}
-
-/**
- * Cognito User Pool event
- * http://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-identity-pools-working-with-aws-lambda-triggers.html
- */
-export interface CognitoUserPoolTriggerEvent {
-    version: number;
-    triggerSource:
-        | 'PreSignUp_SignUp'
-        | 'PreSignUp_ExternalProvider'
-        | 'PostConfirmation_ConfirmSignUp'
-        | 'PreAuthentication_Authentication'
-        | 'PostAuthentication_Authentication'
-        | 'CustomMessage_SignUp'
-        | 'CustomMessage_AdminCreateUser'
-        | 'CustomMessage_ResendCode'
-        | 'CustomMessage_ForgotPassword'
-        | 'CustomMessage_UpdateUserAttribute'
-        | 'CustomMessage_VerifyUserAttribute'
-        | 'CustomMessage_Authentication'
-        | 'DefineAuthChallenge_Authentication'
-        | 'CreateAuthChallenge_Authentication'
-        | 'VerifyAuthChallengeResponse_Authentication'
-        | 'PreSignUp_AdminCreateUser'
-        | 'PostConfirmation_ConfirmForgotPassword'
-        | 'TokenGeneration_HostedAuth'
-        | 'TokenGeneration_Authentication'
-        | 'TokenGeneration_NewPasswordChallenge'
-        | 'TokenGeneration_AuthenticateDevice'
-        | 'TokenGeneration_RefreshTokens'
-        | 'UserMigration_Authentication'
-        | 'UserMigration_ForgotPassword';
-    region: string;
-    userPoolId: string;
-    userName?: string;
-    callerContext: {
-        awsSdkVersion: string;
-        clientId: string;
-    };
-    request: {
-        userAttributes: { [key: string]: string };
-        validationData?: { [key: string]: string };
-        codeParameter?: string;
-        linkParameter?: string;
-        usernameParameter?: string;
-        newDeviceUsed?: boolean;
-        session?: Array<{
-            challengeName:
-                | 'CUSTOM_CHALLENGE'
-                | 'PASSWORD_VERIFIER'
-                | 'SMS_MFA'
-                | 'DEVICE_SRP_AUTH'
-                | 'DEVICE_PASSWORD_VERIFIER'
-                | 'ADMIN_NO_SRP_AUTH';
-            challengeResult: boolean;
-            challengeMetadata?: string;
-        }>;
-        challengeName?: string;
-        privateChallengeParameters?: { [key: string]: string };
-        challengeAnswer?: string;
-        password?: string;
-    };
-    response: {
-        autoConfirmUser?: boolean;
-        autoVerifyPhone?: boolean;
-        autoVerifyEmail?: boolean;
-        smsMessage?: string;
-        emailMessage?: string;
-        emailSubject?: string;
-        challengeName?: string;
-        issueTokens?: boolean;
-        failAuthentication?: boolean;
-        publicChallengeParameters?: { [key: string]: string };
-        privateChallengeParameters?: { [key: string]: string };
-        challengeMetadata?: string;
-        answerCorrect?: boolean;
-        userAttributes?: { [key: string]: string };
-        finalUserStatus?: 'CONFIRMED' | 'RESET_REQUIRED';
-        messageAction?: 'SUPPRESS';
-        desiredDeliveryMediums?: Array<'EMAIL' | 'SMS'>;
-        forceAliasCreation?: boolean;
-        claimsOverrideDetails?: {
-            claimsToAddOrOverride?: { [key: string]: string };
-            claimsToSuppress?: string[];
-            groupOverrideDetails?: null | {
-                groupsToOverride?: string[];
-                iamRolesToOverride?: string[];
-                preferredRole?: string;
-            };
-        };
-    };
-}
-export type CognitoUserPoolEvent = CognitoUserPoolTriggerEvent;
-
-/**
- * CloudFormation Custom Resource event and response
- * http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/crpg-ref.html
- */
-export interface CloudFormationCustomResourceEventCommon {
-    ServiceToken: string;
-    ResponseURL: string;
-    StackId: string;
-    RequestId: string;
-    LogicalResourceId: string;
-    ResourceType: string;
-    ResourceProperties: {
-        ServiceToken: string;
-        [Key: string]: any;
-    };
-}
-
-export interface CloudFormationCustomResourceCreateEvent extends CloudFormationCustomResourceEventCommon {
-    RequestType: 'Create';
-}
-
-export interface CloudFormationCustomResourceUpdateEvent extends CloudFormationCustomResourceEventCommon {
-    RequestType: 'Update';
-    PhysicalResourceId: string;
-    OldResourceProperties: {
-        [Key: string]: any;
-    };
-}
-
-export interface CloudFormationCustomResourceDeleteEvent extends CloudFormationCustomResourceEventCommon {
-    RequestType: 'Delete';
-    PhysicalResourceId: string;
-}
-
-export type CloudFormationCustomResourceEvent =
-    | CloudFormationCustomResourceCreateEvent
-    | CloudFormationCustomResourceUpdateEvent
-    | CloudFormationCustomResourceDeleteEvent;
-
-export interface CloudFormationCustomResourceResponseCommon {
-    PhysicalResourceId: string;
-    StackId: string;
-    RequestId: string;
-    LogicalResourceId: string;
-    Data?: {
-        [Key: string]: any;
-    };
-    NoEcho?: boolean;
-}
-
-export interface CloudFormationCustomResourceSuccessResponse extends CloudFormationCustomResourceResponseCommon {
-    Status: 'SUCCESS';
-    Reason?: string;
-}
-
-export interface CloudFormationCustomResourceFailedResponse extends CloudFormationCustomResourceResponseCommon {
-    Status: 'FAILED';
-    Reason: string;
-}
-
-export type CloudFormationCustomResourceResponse =
-    | CloudFormationCustomResourceSuccessResponse
-    | CloudFormationCustomResourceFailedResponse;
-
-/**
- * See https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-scheduled-event
- */
-export interface ScheduledEvent {
-    account: string;
-    region: string;
-    detail: any;
-    'detail-type': string;
-    source: string;
-    time: string;
-    id: string;
-    resources: string[];
-}
-
-/**
- * See http://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-cloudwatch-logs
- */
-export interface CloudWatchLogsEvent {
-    awslogs: CloudWatchLogsEventData;
-}
-
-export interface CloudWatchLogsEventData {
-    data: string;
-}
-
-export interface CloudWatchLogsDecodedData {
-    owner: string;
-    logGroup: string;
-    logStream: string;
-    subscriptionFilters: string[];
-    messageType: string;
-    logEvents: CloudWatchLogsLogEvent[];
-}
-
-/**
- * See http://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/SubscriptionFilters.html#LambdaFunctionExample
- */
-export interface CloudWatchLogsLogEvent {
-    id: string;
-    timestamp: number;
-    message: string;
-    extractedFields?: { [key: string]: string };
-}
-
-// Context
-// http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-context.html
-export interface Context {
-    // Properties
-    callbackWaitsForEmptyEventLoop: boolean;
-    functionName: string;
-    functionVersion: string;
-    invokedFunctionArn: string;
-    memoryLimitInMB: string;
-    awsRequestId: string;
-    logGroupName: string;
-    logStreamName: string;
-    identity?: CognitoIdentity;
-    clientContext?: ClientContext;
-
-    // Functions
-    getRemainingTimeInMillis(): number;
-
-    // Functions for compatibility with earlier Node.js Runtime v0.10.42
-    // For more details see http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-using-old-runtime.html#nodejs-prog-model-oldruntime-context-methods
-    done(error?: Error, result?: any): void;
-    fail(error: Error | string): void;
-    succeed(messageOrObject: any): void;
-    succeed(message: string, object: any): void;
-}
-
-export interface CognitoIdentity {
-    cognitoIdentityId: string;
-    cognitoIdentityPoolId: string;
-}
-
-export interface ClientContext {
-    client: ClientContextClient;
-    Custom?: any;
-    env: ClientContextEnv;
-}
-
-export interface ClientContextClient {
-    installationId: string;
-    appTitle: string;
-    appVersionName: string;
-    appVersionCode: string;
-    appPackageName: string;
-}
-
-export interface ClientContextEnv {
-    platformVersion: string;
-    platform: string;
-    make: string;
-    model: string;
-    locale: string;
-}
-
-export interface APIGatewayProxyResult {
-    statusCode: number;
-    headers?: {
-        [header: string]: boolean | number | string;
-    };
-    multiValueHeaders?: {
-        [header: string]: Array<boolean | number | string>;
-    };
-    body: string;
-    isBase64Encoded?: boolean;
-}
-export type ProxyResult = APIGatewayProxyResult; // Old name
-
-export interface ALBResult {
-    statusCode: number;
-    statusDescription: string;
-    headers?: { [header: string]: boolean | number | string };
-    multiValueHeaders?: { [header: string]: Array<boolean | number | string> };
-    body?: string;
-    isBase64Encoded: boolean;
-}
-
-/**
- * API Gateway CustomAuthorizer AuthResponse.
- * http://docs.aws.amazon.com/apigateway/latest/developerguide/use-custom-authorizer.html#api-gateway-custom-authorizer-output
- */
-export interface CustomAuthorizerResult {
-    principalId: string;
-    policyDocument: PolicyDocument;
-    context?: AuthResponseContext;
-    usageIdentifierKey?: string;
-}
-export type AuthResponse = CustomAuthorizerResult;
-
-/**
- * API Gateway CustomAuthorizer AuthResponse.PolicyDocument.
- * https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-lambda-authorizer-output.html
- * https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html#Condition
- */
-export interface PolicyDocument {
-    Version: string;
-    Id?: string;
-    Statement: Statement[];
-}
-
-/**
- * API Gateway CustomAuthorizer AuthResponse.PolicyDocument.Condition.
- * https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-control-access-policy-language-overview.html
- * https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html
- */
-export interface ConditionBlock {
-    [condition: string]: Condition | Condition[];
-}
-
-export interface Condition {
-    [key: string]: string | string[];
-}
-
-/**
- * API Gateway CustomAuthorizer AuthResponse.PolicyDocument.Statement.
- * https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-control-access-policy-language-overview.html
- * https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html
- */
-export type Statement = BaseStatement & StatementAction & (StatementResource | StatementPrincipal);
-
-export interface BaseStatement {
-    Effect: string;
-    Sid?: string;
-    Condition?: ConditionBlock;
-}
-
-export type PrincipalValue = { [key: string]: string | string[] } | string | string[];
-export interface MaybeStatementPrincipal {
-    Principal?: PrincipalValue;
-    NotPrincipal?: PrincipalValue;
-}
-export interface MaybeStatementResource {
-    Resource?: string | string[];
-    NotResource?: string | string[];
-}
-export type StatementAction = { Action: string | string[] } | { NotAction: string | string[] };
-export type StatementResource = MaybeStatementPrincipal &
-    ({ Resource: string | string[] } | { NotResource: string | string[] });
-export type StatementPrincipal = MaybeStatementResource &
-    ({ Principal: PrincipalValue } | { NotPrincipal: PrincipalValue });
-/**
- * API Gateway CustomAuthorizer AuthResponse.PolicyDocument.Statement.
- * http://docs.aws.amazon.com/apigateway/latest/developerguide/use-custom-authorizer.html#api-gateway-custom-authorizer-output
- */
-export interface AuthResponseContext {
-    [name: string]: any;
-}
-
-/**
- * CodePipeline events
- * https://docs.aws.amazon.com/codepipeline/latest/userguide/actions-invoke-lambda-function.html
- */
-export interface S3ArtifactLocation {
-    bucketName: string;
-    objectKey: string;
-}
-export interface S3ArtifactStore {
-    type: 'S3';
-    s3Location: S3ArtifactLocation;
-}
-
-export type ArtifactLocation = S3ArtifactStore;
-
-export interface Artifact {
-    name: string;
-    revision: string | null;
-    location: ArtifactLocation;
-}
-
-export interface Credentials {
-    accessKeyId: string;
-    secretAccessKey: string;
-    sessionToken?: string;
-}
-
-export interface EncryptionKey {
-    type: string;
-    id: string;
-}
-
-export interface CodePipelineEvent {
-    'CodePipeline.job': {
-        id: string;
-        accountId: string;
-        data: {
-            actionConfiguration: {
-                configuration: {
-                    FunctionName: string;
-                    UserParameters: string;
-                };
-            };
-            inputArtifacts: Artifact[];
-            outputArtifacts: Artifact[];
-            artifactCredentials: Credentials;
-            encryptionKey?: EncryptionKey & { type: 'KMS' };
-            continuationToken?: string;
-        };
-    };
-}
-
-/**
- * CodePipeline CloudWatch Events
- * https://docs.aws.amazon.com/codepipeline/latest/userguide/detect-state-changes-cloudwatch-events.html
- *
- * The above CodePipelineEvent is when a lambda is invoked by a CodePipeline.
- * These events are when you subscribe to CodePipeline events in CloudWatch.
- *
- * Their documentation says that detail.version is a string, but it is actually an integer
- */
-export type CodePipelineState = 'STARTED' | 'SUCCEEDED' | 'RESUMED' | 'FAILED' | 'CANCELED' | 'SUPERSEDED';
-
-export type CodePipelineStageState = 'STARTED' | 'SUCCEEDED' | 'RESUMED' | 'FAILED' | 'CANCELED';
-
-export type CodePipelineActionState = 'STARTED' | 'SUCCEEDED' | 'FAILED' | 'CANCELED';
-
-export interface CodePipelineCloudWatchPipelineEvent {
-    version: string;
-    id: string;
-    'detail-type': 'CodePipeline Pipeline Execution State Change';
-    source: 'aws.codepipeline';
-    account: string;
-    time: string;
-    region: string;
-    resources: string[];
-    detail: {
-        pipeline: string;
-        version: number;
-        state: CodePipelineState;
-        'execution-id': string;
-    };
-}
-
-export interface CodePipelineCloudWatchStageEvent {
-    version: string;
-    id: string;
-    'detail-type': 'CodePipeline Stage Execution State Change';
-    source: 'aws.codepipeline';
-    account: string;
-    time: string;
-    region: string;
-    resources: string[];
-    detail: {
-        pipeline: string;
-        version: number;
-        'execution-id': string;
-        stage: string;
-        state: CodePipelineStageState;
-    };
-}
-
-export type CodePipelineActionCategory = 'Approval' | 'Build' | 'Deploy' | 'Invoke' | 'Source' | 'Test';
-
-export interface CodePipelineCloudWatchActionEvent {
-    version: string;
-    id: string;
-    'detail-type': 'CodePipeline Action Execution State Change';
-    source: 'aws.codepipeline';
-    account: string;
-    time: string;
-    region: string;
-    resources: string[];
-    detail: {
-        pipeline: string;
-        version: number;
-        'execution-id': string;
-        stage: string;
-        action: string;
-        state: CodePipelineActionState;
-        type: {
-            owner: 'AWS' | 'Custom' | 'ThirdParty';
-            category: CodePipelineActionCategory;
-            provider: string;
-            version: number;
-        };
-    };
-}
-
-export type CodePipelineCloudWatchEvent =
-    | CodePipelineCloudWatchPipelineEvent
-    | CodePipelineCloudWatchStageEvent
-    | CodePipelineCloudWatchActionEvent;
-
-/**
- * CloudFront events
- * http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html
- * Bear in mind that the "example" event structure in the page above includes
- * both an S3 and a Custom origin, which is not strictly allowed. Only one
- * of these per event may be present.
- */
-export interface CloudFrontHeaders {
-    [name: string]: Array<{
-        key?: string;
-        value: string;
-    }>;
-}
-
-export type CloudFrontOrigin =
-    | { s3: CloudFrontS3Origin; custom?: never }
-    | { custom: CloudFrontCustomOrigin; s3?: never };
-
-export interface CloudFrontCustomOrigin {
-    customHeaders: CloudFrontHeaders;
-    domainName: string;
-    keepaliveTimeout: number;
-    path: string;
-    port: number;
-    protocol: 'http' | 'https';
-    readTimeout: number;
-    sslProtocols: string[];
-}
-
-export interface CloudFrontS3Origin {
-    authMethod: 'origin-access-identity' | 'none';
-    customHeaders: CloudFrontHeaders;
-    domainName: string;
-    path: string;
-    region: string;
-}
-
-export interface CloudFrontResponse {
-    status: string;
-    statusDescription: string;
-    headers: CloudFrontHeaders;
-}
-
-export interface CloudFrontRequest {
-    body?: {
-        action: 'read-only' | 'replace';
-        data: string;
-        encoding: 'base64' | 'text';
-        readonly inputTruncated: boolean;
-    };
-    readonly clientIp: string;
-    readonly method: string;
-    uri: string;
-    querystring: string;
-    headers: CloudFrontHeaders;
-    origin?: CloudFrontOrigin;
-}
-
-export interface CloudFrontEvent {
-    config: {
-        readonly distributionDomainName: string;
-        readonly distributionId: string;
-    } & (
-        | { readonly eventType: 'origin-request' | 'origin-response' }
-        | { readonly eventType: 'viewer-request' | 'viewer-response'; readonly requestId: string });
-}
-
-/**
- * Generated HTTP response in viewer request event or origin request event
- *
- * https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-generating-http-responses-in-requests.html#lambda-generating-http-responses-object
- */
-export interface CloudFrontResultResponse {
-    status: string;
-    statusDescription?: string;
-    headers?: CloudFrontHeaders;
-    bodyEncoding?: 'text' | 'base64';
-    body?: string;
-}
-
-/**
- * CloudFront viewer response or origin response event
- *
- * https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html#lambda-event-structure-response
- */
-export interface CloudFrontResponseEvent {
-    Records: Array<{
-        cf: CloudFrontEvent & {
-            readonly request: Pick<CloudFrontRequest, Exclude<keyof CloudFrontRequest, 'body'>>;
-            response: CloudFrontResponse;
-        };
-    }>;
-}
-
-export type CloudFrontRequestResult = undefined | null | CloudFrontResultResponse | CloudFrontRequest;
-
-/**
- * CloudFront viewer request or origin request event
- *
- * https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html#lambda-event-structure-request
- */
-export interface CloudFrontRequestEvent {
-    Records: Array<{
-        cf: CloudFrontEvent & {
-            request: CloudFrontRequest;
-        };
-    }>;
-}
-
-export type CloudFrontResponseResult = undefined | null | CloudFrontResultResponse;
-
-// Kinesis Streams
-// https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-kinesis-streams
-export interface KinesisStreamRecordPayload {
-    approximateArrivalTimestamp: number;
-    data: string;
-    kinesisSchemaVersion: string;
-    partitionKey: string;
-    sequenceNumber: string;
-}
-
-export interface KinesisStreamRecord {
-    awsRegion: string;
-    eventID: string;
-    eventName: string;
-    eventSource: string;
-    eventSourceARN: string;
-    eventVersion: string;
-    invokeIdentityArn: string;
-    kinesis: KinesisStreamRecordPayload;
-}
-
-export interface KinesisStreamEvent {
-    Records: KinesisStreamRecord[];
-}
-
-// Kinesis Data Firehose Event
-// https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-kinesis-firehose
-// https://docs.aws.amazon.com/firehose/latest/dev/data-transformation.html
-// https://aws.amazon.com/blogs/compute/amazon-kinesis-firehose-data-transformation-with-aws-lambda/
-// Examples in the lambda blueprints
-export interface FirehoseTransformationEvent {
-    invocationId: string;
-    deliveryStreamArn: string;
-    region: string;
-    records: FirehoseTransformationEventRecord[];
-}
-
-export interface FirehoseTransformationEventRecord {
-    recordId: string;
-    approximateArrivalTimestamp: number;
-    /** Base64 encoded */
-    data: string;
-    kinesisRecordMetadata?: FirehoseRecordMetadata;
-}
-
-export interface FirehoseRecordMetadata {
-    shardId: string;
-    partitionKey: string;
-    approximateArrivalTimestamp: string;
-    sequenceNumber: string;
-    subsequenceNumber: string;
-}
-
-export type FirehoseRecordTransformationStatus = 'Ok' | 'Dropped' | 'ProcessingFailed';
-
-export interface FirehoseTransformationResultRecord {
-    recordId: string;
-    result: FirehoseRecordTransformationStatus;
-    /** Encode in Base64 */
-    data: string;
-}
-
-export interface FirehoseTransformationResult {
-    records: FirehoseTransformationResultRecord[];
-}
-
-// SQS
-// https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html#supported-event-source-sqs
-export interface SQSRecord {
-    messageId: string;
-    receiptHandle: string;
-    body: string;
-    attributes: SQSRecordAttributes;
-    messageAttributes: SQSMessageAttributes;
-    md5OfBody: string;
-    eventSource: string;
-    eventSourceARN: string;
-    awsRegion: string;
-}
-
-export interface SQSEvent {
-    Records: SQSRecord[];
-}
-
-export interface SQSRecordAttributes {
-    ApproximateReceiveCount: string;
-    SentTimestamp: string;
-    SenderId: string;
-    ApproximateFirstReceiveTimestamp: string;
-}
-
-export type SQSMessageAttributeDataType = 'String' | 'Number' | 'Binary' | string;
-
-export interface SQSMessageAttribute {
-    stringValue?: string;
-    binaryValue?: string;
-    stringListValues: never[]; // Not implemented. Reserved for future use.
-    binaryListValues: never[]; // Not implemented. Reserved for future use.
-    dataType: SQSMessageAttributeDataType;
-}
-
-export interface SQSMessageAttributes {
-    [name: string]: SQSMessageAttribute;
-}
-
-// Lex
-// https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html#supported-event-source-lex
-export interface LexEvent {
-    currentIntent: {
-        name: string;
-        slots: { [name: string]: string | null };
-        slotDetails: LexSlotDetails;
-        confirmationStatus: 'None' | 'Confirmed' | 'Denied';
-    };
-    bot: {
-        name: string;
-        alias: string;
-        version: string;
-    };
-    userId: string;
-    inputTranscript: string;
-    invocationSource: 'DialogCodeHook' | 'FulfillmentCodeHook';
-    outputDialogMode: 'Text' | 'Voice';
-    messageVersion: '1.0';
-    sessionAttributes: { [key: string]: string };
-    requestAttributes: { [key: string]: string } | null;
-}
-
-export interface LexSlotResolution {
-    value: string;
-}
-
-export interface LexSlotDetails {
-    [name: string]: {
-        // The following line only works in TypeScript Version: 3.0, The array should have at least 1 and no more than 5 items
-        // resolutions: [LexSlotResolution, LexSlotResolution?, LexSlotResolution?, LexSlotResolution?, LexSlotResolution?];
-        resolutions: LexSlotResolution[];
-        originalValue: string;
-    };
-}
-
-export interface LexGenericAttachment {
-    title: string;
-    subTitle: string;
-    imageUrl: string;
-    attachmentLinkUrl: string;
-    buttons: Array<{
-        text: string;
-        value: string;
-    }>;
-}
-
-export interface LexDialogActionBase {
-    type: 'Close' | 'ElicitIntent' | 'ElicitSlot' | 'ConfirmIntent';
-    message?: {
-        contentType: 'PlainText' | 'SSML' | 'CustomPayload';
-        content: string;
-    };
-    responseCard?: {
-        version: number;
-        contentType: 'application/vnd.amazonaws.card.generic';
-        genericAttachments: LexGenericAttachment[];
-    };
-}
-
-export interface LexDialogActionClose extends LexDialogActionBase {
-    type: 'Close';
-    fulfillmentState: 'Fulfilled' | 'Failed';
-}
-
-export interface LexDialogActionElicitIntent extends LexDialogActionBase {
-    type: 'ElicitIntent';
-}
-
-export interface LexDialogActionElicitSlot extends LexDialogActionBase {
-    type: 'ElicitSlot';
-    intentName: string;
-    slots: { [name: string]: string | null };
-    slotToElicit: string;
-}
-
-export interface LexDialogActionConfirmIntent extends LexDialogActionBase {
-    type: 'ConfirmIntent';
-    intentName: string;
-    slots: { [name: string]: string | null };
-}
-
-export interface LexDialogActionDelegate {
-    type: 'Delegate';
-    slots: { [name: string]: string | null };
-}
-
-export type LexDialogAction =
-    | LexDialogActionClose
-    | LexDialogActionElicitIntent
-    | LexDialogActionElicitSlot
-    | LexDialogActionConfirmIntent
-    | LexDialogActionDelegate;
-
-export interface LexResult {
-    sessionAttributes?: { [key: string]: string };
-    dialogAction: LexDialogAction;
-}
-
-/**
- * AWS Lambda handler function.
- * http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-handler.html
- *
- * @param event – event data.
- * @param context – runtime information of the Lambda function that is executing.
- * @param callback – optional callback to return information to the caller, otherwise return value is null.
- * @return In the node8.10 runtime, a promise for the lambda result.
- */
-export type Handler<TEvent = any, TResult = any> = (
-    event: TEvent,
-    context: Context,
-    callback: Callback<TResult>,
-) => void | Promise<TResult>;
-
-/**
- * Optional callback parameter.
- * http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-handler.html
- *
- * @param error – an optional parameter that you can use to provide results of the failed Lambda function execution.
- *                It can be a string for Lambda Proxy Integrations
- *                https://docs.aws.amazon.com/apigateway/latest/developerguide/handle-errors-in-lambda-integration.html
- * @param result – an optional parameter that you can use to provide the result of a successful function execution. The result provided must be JSON.stringify compatible.
- */
-export type Callback<TResult = any> = (error?: Error | null | string, result?: TResult) => void;
-
-// Begin defining Handler and Callback types for each API trigger type.
-// Ordered by https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html
-// though that list is incomplete.
-
-export type S3Handler = Handler<S3Event, void>;
-
-export type DynamoDBStreamHandler = Handler<DynamoDBStreamEvent, void>;
-
-export type SNSHandler = Handler<SNSEvent, void>;
-
-// No SESHandler: SES event source is delivered as SNS notifications
-// https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html#supported-event-source-ses
-
-// Result type is weird: docs and samples say to return the mutated event, but it only requires an object
-// with a "response" field, the type of which is specific to the event.triggerType. Leave as any for now.
-export type CognitoUserPoolTriggerHandler = Handler<CognitoUserPoolTriggerEvent>;
-// TODO: Different event/handler types for each event trigger so we can type the result?
-
-export type SQSHandler = Handler<SQSEvent, void>;
-
-// TODO: CognitoSync
-
-export type CloudFormationCustomResourceHandler = Handler<CloudFormationCustomResourceEvent, void>;
-
-// TODO: CloudWatchEvents
-
-export type CloudWatchLogsHandler = Handler<CloudWatchLogsEvent, void>;
-
-// TODO: CodeCommit
-
-export type ScheduledHandler = Handler<ScheduledEvent, void>;
-
-// TODO: AWS Config
-
-// TODO: Alexa
-
-export type LexHandler = Handler<LexEvent, LexResult>;
-export type LexCallback = Callback<LexResult>;
-
-export type APIGatewayProxyHandler = Handler<APIGatewayProxyEvent, APIGatewayProxyResult>;
-export type APIGatewayProxyCallback = Callback<APIGatewayProxyResult>;
-export type ProxyHandler = APIGatewayProxyHandler; // Old name
-export type ProxyCallback = APIGatewayProxyCallback; // Old name
-
-export type ALBHandler = Handler<ALBEvent, ALBResult>;
-export type ALBCallback = Callback<ALBResult>;
-
-// TODO: IoT
-
-export type CodePipelineHandler = Handler<CodePipelineEvent, void>;
-
-export type CodePipelineCloudWatchHandler = Handler<CodePipelineCloudWatchEvent, void>;
-export type CodePipelineCloudWatchPipelineHandler = Handler<CodePipelineCloudWatchPipelineEvent, void>;
-export type CodePipelineCloudWatchStageHandler = Handler<CodePipelineCloudWatchStageEvent, void>;
-export type CodePipelineCloudWatchActionHandler = Handler<CodePipelineCloudWatchActionEvent, void>;
-
-export type CloudFrontRequestHandler = Handler<CloudFrontRequestEvent, CloudFrontRequestResult>;
-export type CloudFrontRequestCallback = Callback<CloudFrontRequestResult>;
-
-export type CloudFrontResponseHandler = Handler<CloudFrontResponseEvent, CloudFrontResponseResult>;
-export type CloudFrontResponseCallback = Callback<CloudFrontResponseResult>;
-
-export type KinesisStreamHandler = Handler<KinesisStreamEvent, void>;
-
-export type FirehoseTransformationCallback = Callback<FirehoseTransformationResult>;
-export type FirehoseTransformationHandler = Handler<FirehoseTransformationEvent, FirehoseTransformationResult>;
-
-export type CustomAuthorizerHandler = Handler<CustomAuthorizerEvent, CustomAuthorizerResult>;
-export type CustomAuthorizerCallback = Callback<CustomAuthorizerResult>;
-
-export type S3BatchHandler = Handler<S3BatchEvent, S3BatchResult>;
-export type S3BatchCallback = Callback<S3BatchResult>;
+export * from "./hander";
+export * from "./common/api-gateway";
+export * from "./common/cloudfront";
+export * from "./trigger/alb";
+// TODO: export * from "./trigger/alexa";
+export * from "./trigger/api-gateway-authorizer";
+export * from "./trigger/api-gateway-proxy";
+// CloudTrail section just describes using S3 to trigger on cloudtrail changes.
+export * from "./trigger/cloudformation-custom-resource";
+export * from "./trigger/cloudfront-request";
+export * from "./trigger/cloudfront-response";
+export * from "./trigger/cloudwatch-events";
+export * from "./trigger/cloudwatch-logs";
+// TODO: export * from "./trigger/codecommit";
+export * from "./trigger/codepipeline";
+export * from "./trigger/codepipeline-cloudwatch";
+export * from "./trigger/codepipeline-cloudwatch-action";
+export * from "./trigger/codepipeline-cloudwatch-pipeline";
+export * from "./trigger/codepipeline-cloudwatch-stage";
+// TODO: export * from "./trigger/cognito-sync";
+export * from "./trigger/cognito-user-pool-trigger";
+// TODO: export * from "./trigger/config";
+export * from "./trigger/dynamodb-stream";
+// ElastiCache section just describes using lambdas in an ElastiCache context (VPC issues, etc.)
+// EC2 events are delivered using cloudwatch events...
+// TODO: export * from "./trigger/iot"; for "IoT Events"
+export * from "./trigger/kinesis-firehose-transformation";
+export * from "./trigger/kinesis-stream";
+export * from "./trigger/lex";
+// RDS events are delivered using SNS events...
+export * from "./trigger/s3";
+export * from "./trigger/s3-batch";
+// SES events are delivered using SNS events...
+export * from "./trigger/sns";
+export * from "./trigger/sqs";
 
 export as namespace AWSLambda;
diff --git a/types/aws-lambda/test/alb-tests.ts b/types/aws-lambda/test/alb-tests.ts
new file mode 100644
index 0000000000..ceeea83fa6
--- /dev/null
+++ b/types/aws-lambda/test/alb-tests.ts
@@ -0,0 +1,30 @@
+import { ALBHandler, ALBResult } from "aws-lambda";
+
+const handler: ALBHandler = async (event, context, callback) => {
+    str = event.httpMethod;
+    str = event.path;
+    str = event.queryStringParameters![str];
+    str = event.headers![str];
+    str = event.multiValueQueryStringParameters![str][num];
+    str = event.multiValueHeaders![str][num];
+    strOrNull = event.body;
+    bool = event.isBase64Encoded;
+    str = event.requestContext.elb.targetGroupArn;
+
+    let result: ALBResult = {
+        statusCode: num,
+        statusDescription: str,
+        isBase64Encoded: bool,
+    };
+    result = {
+        statusCode: num,
+        statusDescription: str,
+        headers: { [str]: boolOrNumOrStr },
+        multiValueHeaders: { [str]: [boolOrNumOrStr] },
+        body: str,
+        isBase64Encoded: bool,
+    };
+    callback(new Error());
+    callback(null, result);
+    return result;
+};
diff --git a/types/aws-lambda/test/api-gateway-tests.ts b/types/aws-lambda/test/api-gateway-tests.ts
new file mode 100644
index 0000000000..2ae90a6b4c
--- /dev/null
+++ b/types/aws-lambda/test/api-gateway-tests.ts
@@ -0,0 +1,186 @@
+import {
+    APIGatewayEvent,
+    APIGatewayEventRequestContext,
+    APIGatewayProxyHandler,
+    APIGatewayProxyResult,
+    AuthResponseContext,
+    Context,
+    CustomAuthorizerHandler,
+    CustomAuthorizerResult,
+    PolicyDocument,
+    ProxyHandler,
+    ProxyCallback,
+    Statement,
+} from "aws-lambda";
+
+let proxyHandler: APIGatewayProxyHandler = async (event, context, callback) => {
+    strOrNull = event.body;
+    str = event.headers['example'];
+    str = event.multiValueHeaders['example'][0];
+    str = event.httpMethod;
+    bool = event.isBase64Encoded;
+    str = event.path;
+    str = event.pathParameters!['example'];
+    str = event.queryStringParameters!['example'];
+    str = event.multiValueQueryStringParameters!['example'][0];
+    str = event.stageVariables!['example'];
+    let requestContext: APIGatewayEventRequestContext;
+    requestContext = event.requestContext;
+    str = event.resource;
+
+    str = requestContext.accountId;
+    str = requestContext.apiId;
+    const authContext: AuthResponseContext | null | undefined = requestContext.authorizer;
+    numOrUndefined = requestContext.connectedAt;
+    strOrUndefined = requestContext.connectionId;
+    strOrUndefined = requestContext.domainName;
+    strOrUndefined = requestContext.eventType;
+    strOrUndefined = requestContext.extendedRequestId;
+    str = requestContext.httpMethod;
+    strOrNull = requestContext.identity.accessKey;
+    strOrNull = requestContext.identity.accountId;
+    strOrNull = requestContext.identity.apiKey;
+    strOrNull = requestContext.identity.apiKeyId;
+    strOrNull = requestContext.identity.caller;
+    strOrNull = requestContext.identity.cognitoAuthenticationProvider;
+    strOrNull = requestContext.identity.cognitoAuthenticationType;
+    strOrNull = requestContext.identity.cognitoIdentityId;
+    strOrNull = requestContext.identity.cognitoIdentityPoolId;
+    strOrNull = requestContext.identity.principalOrgId;
+    str = requestContext.identity.sourceIp;
+    strOrNull = requestContext.identity.user;
+    strOrNull = requestContext.identity.userAgent;
+    strOrNull = requestContext.identity.userArn;
+    strOrUndefined = requestContext.messageDirection;
+    strOrUndefinedOrNull = requestContext.messageId;
+    str = requestContext.path;
+    str = requestContext.stage;
+    str = requestContext.requestId;
+    strOrUndefined = requestContext.requestTime;
+    str = requestContext.resourceId;
+    str = requestContext.resourcePath;
+    strOrUndefined = requestContext.routeKey;
+
+    let result: APIGatewayProxyResult = {
+        statusCode: num,
+        body: str,
+    };
+    result = {
+        statusCode: num,
+        headers: {
+            [str]: str,
+            [str]: bool,
+            [str]: num,
+        },
+        multiValueHeaders: {
+            [str]: [str, bool, num],
+        },
+        isBase64Encoded: true,
+        body: str,
+    };
+
+    callback(new Error());
+    callback(null, result);
+    return result;
+};
+
+const authorizerHandler: CustomAuthorizerHandler = async (event, context, callback) => {
+    str = event.type;
+    str = event.methodArn;
+    strOrUndefined = event.authorizationToken;
+    strOrUndefined = event.resource;
+    strOrUndefined = event.path;
+    strOrUndefined = event.httpMethod;
+    str = event.headers![str];
+    str = event.multiValueHeaders![str][num];
+    str = event.pathParameters![str];
+    str = event.queryStringParameters![str];
+    str = event.multiValueQueryStringParameters![str][num];
+    str = event.stageVariables![str];
+    let requestContext: APIGatewayEventRequestContext;
+    requestContext = event.requestContext!;
+    strOrUndefined = event.domainName;
+    strOrUndefined = event.apiId;
+
+    let statement: Statement = {
+        Action: str,
+        Effect: str,
+        Resource: str,
+    };
+
+    // $ExpectError
+    statement = { Effect: str, Action: str, Principal: 123, };
+
+    // Bad Resource
+    // $ExpectError
+    statement = { Effect: str, Action: str, Resource: 123, };
+
+    // Bad Resource with valid Principal
+    // $ExpectError
+    statement = { Effect: str, Action: str, Principal: { Service: str }, Resource: 123, };
+
+    // Bad principal with valid Resource
+    // $ExpectError
+    statement = { Effect: str, Action: str, Principal: 123, Resource: str, };
+
+    // No Effect
+    // $ExpectError
+    statement = { Action: str, Principal: str };
+
+    statement = {
+        Sid: str,
+        Action: [str, str],
+        Effect: str,
+        Resource: [str, str],
+        Condition: {
+            condition1: { key: 'value' },
+            condition2: [
+                {
+                    key1: 'value',
+                    key2: 'value',
+                },
+                {
+                    key3: 'value',
+                },
+            ],
+        },
+        Principal: [str, str],
+        NotPrincipal: [str, str],
+    };
+
+    statement = { Action: str, Principal: str, Effect: str };
+
+    statement = { Action: str, NotPrincipal: { Service: str }, Effect: str };
+
+    statement = { Effect: str, NotAction: str, NotResource: str };
+
+    let policyDocument: PolicyDocument = { Version: str, Statement: [statement] };
+
+    policyDocument = { Version: str, Statement: [statement, statement] };
+
+    const authResponseContext: AuthResponseContext = {
+        stringKey: str,
+        numberKey: num,
+        booleanKey: bool,
+    };
+
+    let result: CustomAuthorizerResult = {
+        principalId: str,
+        policyDocument,
+        context: authResponseContext,
+    };
+
+    result = {
+        principalId: str,
+        policyDocument,
+    };
+
+    callback(new Error());
+    callback(null, result);
+    return result;
+};
+
+// Test old names
+const oldNameProxyHandler: ProxyHandler = (event: APIGatewayEvent, context: Context, cb: ProxyCallback) => {};
+
+proxyHandler = oldNameProxyHandler;
diff --git a/types/aws-lambda/test/cloudformation-tests.ts b/types/aws-lambda/test/cloudformation-tests.ts
new file mode 100644
index 0000000000..ffcceca2d0
--- /dev/null
+++ b/types/aws-lambda/test/cloudformation-tests.ts
@@ -0,0 +1,74 @@
+import {
+    CloudFormationCustomResourceFailedResponse,
+    CloudFormationCustomResourceHandler,
+    CloudFormationCustomResourceResponse, CloudFormationCustomResourceSuccessResponse,
+} from "aws-lambda";
+
+const handler: CloudFormationCustomResourceHandler = async (event, context, callback) => {
+    switch (event.RequestType) {
+        case 'Create':
+            str = event.LogicalResourceId;
+            str = event.RequestId;
+            anyObj = event.ResourceProperties;
+            str = event.ResourceProperties.ServiceToken;
+            str = event.ResourceType;
+            str = event.ResponseURL;
+            str = event.ServiceToken;
+            str = event.StackId;
+            break;
+        case 'Update':
+            anyObj = event.OldResourceProperties;
+            break;
+        case 'Delete':
+            str = event.PhysicalResourceId;
+            break;
+    }
+
+    let response: CloudFormationCustomResourceResponse;
+    response = {
+        Data: {
+            [str]: anyObj,
+        },
+        LogicalResourceId: str,
+        PhysicalResourceId: str,
+        Reason: strOrUndefined,
+        RequestId: str,
+        StackId: str,
+        Status: "SUCCESS",
+        NoEcho: boolOrUndefined,
+    };
+
+    let successResponse: CloudFormationCustomResourceSuccessResponse;
+    let failedResponse: CloudFormationCustomResourceFailedResponse;
+    successResponse = {
+        LogicalResourceId: str,
+        PhysicalResourceId: str,
+        RequestId: str,
+        StackId: str,
+        Status: "SUCCESS",
+    };
+    successResponse = {
+        Data: anyObj,
+        LogicalResourceId: str,
+        PhysicalResourceId: str,
+        Reason: strOrUndefined,
+        RequestId: str,
+        StackId: str,
+        Status: "SUCCESS",
+        NoEcho: boolOrUndefined,
+    };
+    failedResponse = {
+        Data: anyObj,
+        LogicalResourceId: str,
+        PhysicalResourceId: str,
+        Reason: str,
+        RequestId: str,
+        StackId: str,
+        Status: "FAILED",
+    };
+    response = successResponse;
+    response = failedResponse;
+
+    callback();
+    callback(new Error());
+};
diff --git a/types/aws-lambda/test/cloudfront-tests.ts b/types/aws-lambda/test/cloudfront-tests.ts
new file mode 100644
index 0000000000..5b141ae205
--- /dev/null
+++ b/types/aws-lambda/test/cloudfront-tests.ts
@@ -0,0 +1,279 @@
+import {
+    CloudFrontHeaders,
+    CloudFrontRequestEvent,
+    CloudFrontRequestHandler,
+    CloudFrontRequestResult,
+    CloudFrontResponseEvent,
+    CloudFrontResponseHandler,
+    CloudFrontResponseResult,
+    CloudFrontS3Origin,
+    CloudFrontCustomOrigin,
+} from "aws-lambda";
+
+// TODO: Update test to read all event properties, and write all result
+//       properties, like the user will.
+
+const cloudFrontHeaders: CloudFrontHeaders = {
+    'content-type': [{ value: 'text/plain' }],
+    'x-foo-bar': [{ key: 'X-Foo-Bar', value: 'example' }],
+};
+
+const requestHandler: CloudFrontRequestHandler = async (event, context, cb) => {
+    event = requestWithCustomOriginEvent;
+    // $ExpectType CloudFrontRequestEvent
+    event;
+    let request = event.Records[0].cf.request;
+
+    let s3Origin: CloudFrontS3Origin = {
+        authMethod: 'none',
+        customHeaders: {},
+        domainName: 'example.com',
+        path: '/',
+        region: 'us-east-1',
+    };
+
+    if (request.origin && request.origin.custom) {
+        request.origin.custom.domainName;
+        request.origin.custom.domainName = 'example2.com';
+
+        // $ExpectError
+        s3Origin = request.origin.s3;
+
+        // $ExpectError
+        request.origin.s3.path = '/';
+    }
+
+    let customOrigin: CloudFrontCustomOrigin = {
+        customHeaders: {},
+        domainName: 'example.com',
+        keepaliveTimeout: 60,
+        path: '/',
+        port: 80,
+        protocol: 'http',
+        readTimeout: 30,
+        sslProtocols: [],
+    };
+
+    event = requestWithS3OriginEvent;
+    // $ExpectType CloudFrontRequestEvent
+    event;
+    request = event.Records[0].cf.request;
+    if (request.origin && request.origin.s3) {
+        request.origin.s3.path;
+        request.origin.s3.path = '/new_path';
+
+        // $ExpectError
+        customOrigin = request.origin.custom;
+
+        // $ExpectError
+        request.origin.custom.path = '/';
+    }
+
+    let result: CloudFrontRequestResult;
+    // Result can be either nullish (use current request), a replaced request, or an immediate response
+    result = undefined;
+    result = null;
+    result = { clientIp: str, method: str, uri: str, querystring: str, headers: cloudFrontHeaders };
+    result = { status: str };
+    result = { status: str, statusDescription: str, headers: cloudFrontHeaders, bodyEncoding: "text", body: str };
+    // $ExpectError
+    result = {};
+
+    cb(new Error());
+    cb(null, result);
+    return result;
+};
+
+const responseHandler: CloudFrontResponseHandler = async (event, context, callback) => {
+    let result: CloudFrontResponseResult;
+    // Result can be either nullish (use current response) or a replaced response, but not a request
+    result = undefined;
+    result = null;
+    result = { status: str };
+    // $ExpectError
+    result = { clientIp: str, method: str, uri: str, querystring: str, headers: cloudFrontHeaders };
+    result = { status: str, statusDescription: str, headers: cloudFrontHeaders, bodyEncoding: "text", body: str };
+    result = { status: str, bodyEncoding: "base64", body: str };
+    // $ExpectError
+    result = { status: str, bodyEncoding: "invalid-encoding", body: str };
+
+    callback(new Error());
+    callback(null, result);
+    return result;
+};
+
+/* CloudFront events, see http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html */
+
+const requestWithCustomOriginEvent: CloudFrontRequestEvent = {
+    Records: [
+        {
+            cf: {
+                config: {
+                    distributionDomainName: 'd123.cloudfront.net',
+                    distributionId: 'EDFDVBD6EXAMPLE',
+                    eventType: 'viewer-request',
+                    requestId: 'MRVMF7KydIvxMWfJIglgwHQwZsbG2IhRJ07sn9AkKUFSHS9EXAMPLE==',
+                },
+                request: {
+                    body: {
+                        action: 'read-only',
+                        data: 'eyJ1c2VybmFtZSI6IkxhbWJkYUBFZGdlIiwiY29tbWVudCI6IlRoaXMgaXMgcmVxdWVzdCBib2R5In0=',
+                        encoding: 'base64',
+                        inputTruncated: false,
+                    },
+                    clientIp: '2001:0db8:85a3:0:0:8a2e:0370:7334',
+                    querystring: 'size=large',
+                    uri: '/picture.jpg',
+                    method: 'GET',
+                    headers: {
+                        host: [
+                            {
+                                key: 'Host',
+                                value: 'd111111abcdef8.cloudfront.net',
+                            },
+                        ],
+                        'user-agent': [
+                            {
+                                key: 'User-Agent',
+                                value: 'curl/7.51.0',
+                            },
+                        ],
+                    },
+                    origin: {
+                        custom: {
+                            customHeaders: {
+                                'my-origin-custom-header': [
+                                    {
+                                        key: 'My-Origin-Custom-Header',
+                                        value: 'Test',
+                                    },
+                                ],
+                            },
+                            domainName: 'example.com',
+                            keepaliveTimeout: 5,
+                            path: '/custom_path',
+                            port: 443,
+                            protocol: 'https',
+                            readTimeout: 5,
+                            sslProtocols: ['TLSv1', 'TLSv1.1'],
+                        },
+                    },
+                },
+            },
+        },
+    ],
+};
+
+const requestWithS3OriginEvent: CloudFrontRequestEvent = {
+    Records: [
+        {
+            cf: {
+                config: {
+                    distributionDomainName: 'd123.cloudfront.net',
+                    distributionId: 'EDFDVBD6EXAMPLE',
+                    eventType: 'viewer-request',
+                    requestId: 'MRVMF7KydIvxMWfJIglgwHQwZsbG2IhRJ07sn9AkKUFSHS9EXAMPLE==',
+                },
+                request: {
+                    body: {
+                        action: 'read-only',
+                        data: 'eyJ1c2VybmFtZSI6IkxhbWJkYUBFZGdlIiwiY29tbWVudCI6IlRoaXMgaXMgcmVxdWVzdCBib2R5In0=',
+                        encoding: 'base64',
+                        inputTruncated: false,
+                    },
+                    clientIp: '2001:0db8:85a3:0:0:8a2e:0370:7334',
+                    querystring: 'size=large',
+                    uri: '/picture.jpg',
+                    method: 'GET',
+                    headers: {
+                        host: [
+                            {
+                                key: 'Host',
+                                value: 'd111111abcdef8.cloudfront.net',
+                            },
+                        ],
+                        'user-agent': [
+                            {
+                                key: 'User-Agent',
+                                value: 'curl/7.51.0',
+                            },
+                        ],
+                    },
+                    origin: {
+                        s3: {
+                            authMethod: 'origin-access-identity',
+                            customHeaders: {
+                                'my-origin-custom-header': [
+                                    {
+                                        key: 'My-Origin-Custom-Header',
+                                        value: 'Test',
+                                    },
+                                ],
+                            },
+                            domainName: 'my-bucket.s3.amazonaws.com',
+                            path: '/s3_path',
+                            region: 'us-east-1',
+                        },
+                    },
+                },
+            },
+        },
+    ],
+};
+
+const responseEvent: CloudFrontResponseEvent = {
+    Records: [
+        {
+            cf: {
+                config: {
+                    distributionDomainName: 'd123.cloudfront.net',
+                    distributionId: 'EDFDVBD6EXAMPLE',
+                    eventType: 'viewer-response',
+                    requestId: 'xGN7KWpVEmB9Dp7ctcVFQC4E-nrcOcEKS3QyAez--06dV7TEXAMPLE==',
+                },
+                request: {
+                    clientIp: '2001:0db8:85a3:0:0:8a2e:0370:7334',
+                    method: 'GET',
+                    uri: '/picture.jpg',
+                    querystring: 'size=large',
+                    headers: {
+                        host: [
+                            {
+                                key: 'Host',
+                                value: 'd111111abcdef8.cloudfront.net',
+                            },
+                        ],
+                        'user-agent': [
+                            {
+                                key: 'User-Agent',
+                                value: 'curl/7.18.1',
+                            },
+                        ],
+                    },
+                },
+                response: {
+                    status: '200',
+                    statusDescription: 'OK',
+                    headers: {
+                        server: [
+                            {
+                                key: 'Server',
+                                value: 'MyCustomOrigin',
+                            },
+                        ],
+                        'set-cookie': [
+                            {
+                                key: 'Set-Cookie',
+                                value: 'theme=light',
+                            },
+                            {
+                                key: 'Set-Cookie',
+                                value: 'sessionToken=abc123; Expires=Wed, 09 Jun 2021 10:18:14 GMT',
+                            },
+                        ],
+                    },
+                },
+            },
+        },
+    ],
+};
diff --git a/types/aws-lambda/test/cloudwatch-tests.ts b/types/aws-lambda/test/cloudwatch-tests.ts
new file mode 100644
index 0000000000..815d2bc61c
--- /dev/null
+++ b/types/aws-lambda/test/cloudwatch-tests.ts
@@ -0,0 +1,45 @@
+/// <reference types="node" />
+
+import {
+    CloudWatchLogsDecodedData,
+    CloudWatchLogsHandler,
+    CloudWatchLogsLogEvent,
+    ScheduledHandler,
+} from "aws-lambda";
+
+import { gunzipSync } from "zlib";
+
+const logsHandler: CloudWatchLogsHandler = async (event, context, callback) => {
+    const data: CloudWatchLogsDecodedData = JSON.parse(
+        gunzipSync(Buffer.from(event.awslogs.data, "base64")).toString()
+    );
+
+    str = data.owner;
+    str = data.logGroup;
+    str = data.logStream;
+    str = data.subscriptionFilters[0];
+    str = data.messageType;
+
+    const logEvent: CloudWatchLogsLogEvent = data.logEvents[0];
+    str = logEvent.id;
+    num = logEvent.timestamp;
+    str = logEvent.message;
+    str = logEvent.extractedFields!['example'];
+
+    callback();
+    callback(new Error());
+};
+
+// Technically part of cloudwatch
+const scheduledHandler: ScheduledHandler = async (event, context, callback) => {
+    str = event.account;
+    anyObj = event.detail;
+    str = event.id;
+    str = event.region;
+    str = event.resources[0];
+    str = event.source;
+    str = event.time;
+
+    callback();
+    callback(new Error());
+};
diff --git a/types/aws-lambda/test/codepipeline-tests.ts b/types/aws-lambda/test/codepipeline-tests.ts
new file mode 100644
index 0000000000..7d481dd9a0
--- /dev/null
+++ b/types/aws-lambda/test/codepipeline-tests.ts
@@ -0,0 +1,77 @@
+import { CodePipelineCloudWatchEvent, CodePipelineEvent } from "aws-lambda";
+
+// TODO
+
+/* CodePipeline events https://docs.aws.amazon.com/codepipeline/latest/userguide/actions-invoke-lambda-function.html#actions-invoke-lambda-function-json-event-example */
+const CodePipelineEvent: CodePipelineEvent = {
+    'CodePipeline.job': {
+        id: '11111111-abcd-1111-abcd-111111abcdef',
+        accountId: '111111111111',
+        data: {
+            actionConfiguration: {
+                configuration: {
+                    FunctionName: 'MyLambdaFunctionForAWSCodePipeline',
+                    UserParameters: 'some-input-such-as-a-URL',
+                },
+            },
+            inputArtifacts: [
+                {
+                    location: {
+                        s3Location: {
+                            bucketName:
+                                'the name of the bucket configured as the pipeline artifact store in Amazon S3, for example codepipeline-us-east-2-1234567890',
+                            objectKey: 'the name of the application, for example CodePipelineDemoApplication.zip',
+                        },
+                        type: 'S3',
+                    },
+                    revision: null,
+                    name: 'ArtifactName',
+                },
+            ],
+            outputArtifacts: [],
+            artifactCredentials: {
+                secretAccessKey: 'wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY',
+                sessionToken: `MIICiTCCAfICCQD6m7oRw0uXOjANBgkqhkiG9w
+ 0BAQUFADCBiDELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAldBMRAwDgYDVQQHEwdTZ
+ WF0dGxlMQ8wDQYDVQQKEwZBbWF6b24xFDASBgNVBAsTC0lBTSBDb25zb2xlMRIw
+ EAYDVQQDEwlUZXN0Q2lsYWMxHzAdBgkqhkiG9w0BCQEWEG5vb25lQGFtYXpvbi5
+ jb20wHhcNMTEwNDI1MjA0NTIxWhcNMTIwNDI0MjA0NTIxWjCBiDELMAkGA1UEBh
+ MCVVMxCzAJBgNVBAgTAldBMRAwDgYDVQQHEwdTZWF0dGxlMQ8wDQYDVQQKEwZBb
+ WF6b24xFDASBgNVBAsTC0lBTSBDb25zb2xlMRIwEAYDVQQDEwlUZXN0Q2lsYWMx
+ HzAdBgkqhkiG9w0BCQEWEG5vb25lQGFtYXpvbi5jb20wgZ8wDQYJKoZIhvcNAQE
+ BBQADgY0AMIGJAoGBAMaK0dn+a4GmWIWJ21uUSfwfEvySWtC2XADZ4nB+BLYgVI
+ k60CpiwsZ3G93vUEIO3IyNoH/f0wYK8m9TrDHudUZg3qX4waLG5M43q7Wgc/MbQ
+ ITxOUSQv7c7ugFFDzQGBzZswY6786m86gpEIbb3OhjZnzcvQAaRHhdlQWIMm2nr
+ AgMBAAEwDQYJKoZIhvcNAQEFBQADgYEAtCu4nUhVVxYUntneD9+h8Mg9q6q+auN
+ KyExzyLwaxlAoo7TJHidbtS4J5iNmZgXL0FkbFFBjvSfpJIlJ00zbhNYS5f6Guo
+ EDmFJl0ZxBHjJnyp378OD8uTs7fLvjx79LjSTbNYiytVbZPQUQ5Yaxu2jXnimvw
+ 3rrszlaEXAMPLE=`,
+                accessKeyId: 'AKIAIOSFODNN7EXAMPLE',
+            },
+            continuationToken: 'A continuation token if continuing job',
+        },
+    },
+};
+
+CodePipelineEvent['CodePipeline.job'].data.encryptionKey = { type: 'KMS', id: 'key' };
+
+/* CodePipeline CloudWatch Events
+ * see https://docs.aws.amazon.com/codepipeline/latest/userguide/detect-state-changes-cloudwatch-events.html
+ * Their documentation says that detail.version is a string, but it is actually an integer
+ */
+const CodePipelineCloudWatchEvent: CodePipelineCloudWatchEvent = {
+    version: '0',
+    id: 'event_Id',
+    'detail-type': 'CodePipeline Pipeline Execution State Change',
+    source: 'aws.codepipeline',
+    account: 'Pipeline_Account',
+    time: 'TimeStamp',
+    region: 'us-east-1',
+    resources: ['arn:aws:codepipeline:us-east-1:account_ID:myPipeline'],
+    detail: {
+        pipeline: 'myPipeline',
+        version: 1,
+        state: 'STARTED',
+        'execution-id': 'execution_Id',
+    },
+};
diff --git a/types/aws-lambda/test/cognito-tests.ts b/types/aws-lambda/test/cognito-tests.ts
new file mode 100644
index 0000000000..cab5581bc8
--- /dev/null
+++ b/types/aws-lambda/test/cognito-tests.ts
@@ -0,0 +1,114 @@
+// TODO: Update test to read all event properties, and write all result
+//       properties, like the user will.
+
+import { CognitoUserPoolTriggerHandler } from "aws-lambda";
+
+const handler: CognitoUserPoolTriggerHandler = async (event, context, callback) => {
+    num = event.version;
+    event.triggerSource === 'PreSignUp_SignUp';
+    event.triggerSource === 'PreSignUp_ExternalProvider';
+    event.triggerSource === 'PostConfirmation_ConfirmSignUp';
+    event.triggerSource === 'PreAuthentication_Authentication';
+    event.triggerSource === 'PostAuthentication_Authentication';
+    event.triggerSource === 'CustomMessage_SignUp';
+    event.triggerSource === 'CustomMessage_AdminCreateUser';
+    event.triggerSource === 'CustomMessage_ResendCode';
+    event.triggerSource === 'CustomMessage_ForgotPassword';
+    event.triggerSource === 'CustomMessage_UpdateUserAttribute';
+    event.triggerSource === 'CustomMessage_VerifyUserAttribute';
+    event.triggerSource === 'CustomMessage_Authentication';
+    event.triggerSource === 'DefineAuthChallenge_Authentication';
+    event.triggerSource === 'CreateAuthChallenge_Authentication';
+    event.triggerSource === 'VerifyAuthChallengeResponse_Authentication';
+    event.triggerSource === 'PreSignUp_AdminCreateUser';
+    event.triggerSource === 'PostConfirmation_ConfirmForgotPassword';
+    event.triggerSource === 'TokenGeneration_HostedAuth';
+    event.triggerSource === 'TokenGeneration_Authentication';
+    event.triggerSource === 'TokenGeneration_NewPasswordChallenge';
+    event.triggerSource === 'TokenGeneration_AuthenticateDevice';
+    event.triggerSource === 'TokenGeneration_RefreshTokens';
+    event.triggerSource === 'UserMigration_Authentication';
+    event.triggerSource === 'UserMigration_ForgotPassword';
+    // $ExpectError
+    event.triggerSource === 'NoSuch_Trigger';
+
+    str = event.region;
+    str = event.userPoolId;
+    strOrUndefined = event.userName;
+    str = event.callerContext.awsSdkVersion;
+    str = event.callerContext.clientId;
+    str = event.request.userAttributes['email'];
+    str = event.request.validationData!['k1'];
+    strOrUndefined = event.request.codeParameter;
+    strOrUndefined = event.request.linkParameter;
+    strOrUndefined = event.request.usernameParameter;
+    boolOrUndefined = event.request.newDeviceUsed;
+    event.request.session![0].challengeName === 'CUSTOM_CHALLENGE';
+    event.request.session![0].challengeName === 'PASSWORD_VERIFIER';
+    event.request.session![0].challengeName === 'SMS_MFA';
+    event.request.session![0].challengeName === 'DEVICE_SRP_AUTH';
+    event.request.session![0].challengeName === 'DEVICE_PASSWORD_VERIFIER';
+    event.request.session![0].challengeName === 'ADMIN_NO_SRP_AUTH';
+    bool = event.request.session![0].challengeResult;
+    strOrUndefined = event.request.session![0].challengeMetadata;
+    strOrUndefined = event.request.challengeName;
+    str = event.request.privateChallengeParameters!['answer'];
+    str = event.request.challengeAnswer!;
+    strOrUndefined = event.request.password;
+    boolOrUndefined = event.response.answerCorrect;
+    strOrUndefined = event.response.smsMessage;
+    strOrUndefined = event.response.emailMessage;
+    strOrUndefined = event.response.emailSubject;
+    strOrUndefined = event.response.challengeName;
+    boolOrUndefined = event.response.issueTokens;
+    boolOrUndefined = event.response.failAuthentication;
+    str = event.response.publicChallengeParameters!['captchaUrl'];
+    str = event.response.privateChallengeParameters!['answer'];
+    strOrUndefined = event.response.challengeMetadata;
+    boolOrUndefined = event.response.answerCorrect;
+    str = event.response.userAttributes!['username'];
+    event.response.finalUserStatus === 'CONFIRMED';
+    event.response.finalUserStatus === 'RESET_REQUIRED';
+    event.response.messageAction === 'SUPPRESS';
+    event.response.desiredDeliveryMediums === ['EMAIL'];
+    event.response.desiredDeliveryMediums === ['SMS'];
+    event.response.desiredDeliveryMediums === ['SMS', 'EMAIL'];
+    boolOrUndefined = event.response.forceAliasCreation;
+
+    // From AWS examples
+    event.response = {
+        claimsOverrideDetails: {
+            claimsToAddOrOverride: {
+                attribute_key2: 'attribute_value2',
+                attribute_key: 'attribute_value',
+            },
+            claimsToSuppress: ['email'],
+        },
+    };
+    event.response = {
+        claimsOverrideDetails: {
+            claimsToAddOrOverride: {
+                attribute_key2: 'attribute_value2',
+                attribute_key: 'attribute_value',
+            },
+            claimsToSuppress: ['email'],
+            groupOverrideDetails: {
+                groupsToOverride: ['group-A', 'group-B', 'group-C'],
+                iamRolesToOverride: [
+                    'arn:aws:iam::XXXXXXXXXXXX:role/sns_callerA',
+                    'arn:aws:iam::XXXXXXXXX:role/sns_callerB',
+                    'arn:aws:iam::XXXXXXXXXX:role/sns_callerC',
+                ],
+                preferredRole: 'arn:aws:iam::XXXXXXXXXXX:role/sns_caller',
+            },
+        },
+    };
+    event.response.claimsOverrideDetails!.groupOverrideDetails = null;
+
+    callback(new Error());
+    callback(null, event);
+    callback(null, {
+        response: event.response,
+    });
+    return event;
+};
diff --git a/types/aws-lambda/test/dynamodb-tests.ts b/types/aws-lambda/test/dynamodb-tests.ts
new file mode 100644
index 0000000000..9f043de9ce
--- /dev/null
+++ b/types/aws-lambda/test/dynamodb-tests.ts
@@ -0,0 +1,98 @@
+import { DynamoDBStreamEvent } from "aws-lambda";
+
+// TODO: Update test to read all event properties, and write all result
+//       properties, like the user will.
+
+const event: DynamoDBStreamEvent = {
+    Records: [
+        {
+            eventID: '1',
+            eventVersion: '1.0',
+            dynamodb: {
+                Keys: {
+                    Id: {
+                        N: '101',
+                    },
+                },
+                NewImage: {
+                    Message: {
+                        S: 'New item!',
+                    },
+                    Id: {
+                        N: '101',
+                    },
+                },
+                StreamViewType: 'NEW_AND_OLD_IMAGES',
+                SequenceNumber: '111',
+                SizeBytes: 26,
+            },
+            awsRegion: 'us-west-2',
+            eventName: 'INSERT',
+            eventSourceARN:
+                'arn:aws:dynamodb:us-west-2:account-id:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899',
+            eventSource: 'aws:dynamodb',
+        },
+        {
+            eventID: '2',
+            eventVersion: '1.0',
+            dynamodb: {
+                OldImage: {
+                    Message: {
+                        S: 'New item!',
+                    },
+                    Id: {
+                        N: '101',
+                    },
+                },
+                SequenceNumber: '222',
+                Keys: {
+                    Id: {
+                        N: '101',
+                    },
+                },
+                SizeBytes: 59,
+                NewImage: {
+                    Message: {
+                        S: 'This item has changed',
+                    },
+                    Id: {
+                        N: '101',
+                    },
+                },
+                StreamViewType: 'NEW_AND_OLD_IMAGES',
+            },
+            awsRegion: 'us-west-2',
+            eventName: 'MODIFY',
+            eventSourceARN:
+                'arn:aws:dynamodb:us-west-2:account-id:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899',
+            eventSource: 'aws:dynamodb',
+        },
+        {
+            eventID: '3',
+            eventVersion: '1.0',
+            dynamodb: {
+                Keys: {
+                    Id: {
+                        N: '101',
+                    },
+                },
+                SizeBytes: 38,
+                SequenceNumber: '333',
+                OldImage: {
+                    Message: {
+                        S: 'This item has changed',
+                    },
+                    Id: {
+                        N: '101',
+                    },
+                },
+                StreamViewType: 'NEW_AND_OLD_IMAGES',
+            },
+            awsRegion: 'us-west-2',
+            eventName: 'REMOVE',
+            eventSourceARN:
+                'arn:aws:dynamodb:us-west-2:account-id:table/ExampleTableWithStream/stream/2015-06-27T00:48:05.899',
+            eventSource: 'aws:dynamodb',
+        },
+    ],
+};
diff --git a/types/aws-lambda/test/kinesis-tests.ts b/types/aws-lambda/test/kinesis-tests.ts
new file mode 100644
index 0000000000..f04dc17a6a
--- /dev/null
+++ b/types/aws-lambda/test/kinesis-tests.ts
@@ -0,0 +1,50 @@
+import {
+    FirehoseRecordTransformationStatus,
+    FirehoseTransformationHandler, FirehoseTransformationResult,
+    KinesisStreamHandler,
+    KinesisStreamRecord,
+    KinesisStreamRecordPayload,
+} from "aws-lambda";
+
+const handler: KinesisStreamHandler = async (event, context, callback) => {
+    let kinesisStreamRecord: KinesisStreamRecord;
+    let kinesisStreamRecordPayload: KinesisStreamRecordPayload;
+
+    kinesisStreamRecord = event.Records[num];
+
+    str = kinesisStreamRecord.awsRegion;
+    str = kinesisStreamRecord.eventID;
+    str = kinesisStreamRecord.eventName;
+    str = kinesisStreamRecord.eventSource;
+    str = kinesisStreamRecord.eventSourceARN;
+    str = kinesisStreamRecord.eventVersion;
+    str = kinesisStreamRecord.invokeIdentityArn;
+    kinesisStreamRecordPayload = kinesisStreamRecord.kinesis;
+
+    num = kinesisStreamRecordPayload.approximateArrivalTimestamp;
+    str = kinesisStreamRecordPayload.data;
+    str = kinesisStreamRecordPayload.kinesisSchemaVersion;
+    str = kinesisStreamRecordPayload.partitionKey;
+    str = kinesisStreamRecordPayload.sequenceNumber;
+
+    callback();
+    callback(new Error());
+};
+
+const firehoseHandler: FirehoseTransformationHandler = async (event, context, callback) => {
+    str = event.records[0].recordId;
+
+    const result: FirehoseTransformationResult = {
+        records: [
+            {
+                recordId: event.records[0].recordId,
+                result: 'Ok' as FirehoseRecordTransformationStatus,
+                data: 'eyJmb28iOiJiYXIifQ==',
+            },
+        ],
+    };
+
+    callback(new Error());
+    callback(null, result);
+    return result;
+};
diff --git a/types/aws-lambda/test/lex-tests.ts b/types/aws-lambda/test/lex-tests.ts
new file mode 100644
index 0000000000..408bf451a0
--- /dev/null
+++ b/types/aws-lambda/test/lex-tests.ts
@@ -0,0 +1,122 @@
+import {
+    LexDialogAction,
+    LexDialogActionBase,
+    LexDialogActionClose,
+    LexDialogActionConfirmIntent,
+    LexDialogActionDelegate,
+    LexDialogActionElicitIntent,
+    LexDialogActionElicitSlot,
+    LexEvent,
+    LexGenericAttachment,
+    LexHandler,
+    LexResult,
+} from "aws-lambda";
+
+// TODO: Update test to read all event properties, and write all result
+//       properties, like the user will.
+
+const handler: LexHandler = async (event, context, callback) => {
+    lexEvent = event;
+
+    let result: LexResult;
+    result = {
+        dialogAction: lexDialogAction,
+    };
+    result = {
+        sessionAttributes: {
+            attrib1: 'Value One',
+        },
+        dialogAction: {
+            type: 'Close',
+            fulfillmentState: 'Failed',
+        },
+    };
+
+    callback(new Error());
+    callback(null, result);
+    return result;
+};
+
+declare let lexEvent: LexEvent;
+lexEvent = {
+    currentIntent: {
+        name: 'intent-name',
+        slots: {
+            slot1: null,
+            slot2: 'value2',
+        },
+        slotDetails: {
+            slot1: {
+                resolutions: [{ value: 'value1' }],
+                originalValue: 'originalValue',
+            },
+        },
+        confirmationStatus: 'None',
+    },
+    bot: {
+        name: 'bot name',
+        alias: 'bot alias',
+        version: 'bot version',
+    },
+    userId: 'User ID specified in the POST request to Amazon Lex.',
+    inputTranscript: 'Text used to process the request',
+    invocationSource: 'FulfillmentCodeHook',
+    outputDialogMode: 'Text',
+    messageVersion: '1.0',
+    sessionAttributes: {
+        key1: 'value1',
+        key2: 'value2',
+    },
+    requestAttributes: {
+        key1: 'value1',
+        key2: 'value2',
+    },
+};
+
+declare let lexDialogAction: LexDialogAction;
+declare let lexDialogActionBase: LexDialogActionBase;
+declare let lexDialogActionClose: LexDialogActionClose;
+declare let lexDialogActionConfirmIntent: LexDialogActionConfirmIntent;
+declare let lexDialogActionDelegate: LexDialogActionDelegate;
+declare let lexDialogActionElicitIntent: LexDialogActionElicitIntent;
+declare let lexDialogActionElicitSlot: LexDialogActionElicitSlot;
+declare let lexGenericAttachment: LexGenericAttachment;
+
+str = lexGenericAttachment.title;
+str = lexGenericAttachment.subTitle;
+str = lexGenericAttachment.imageUrl;
+str = lexGenericAttachment.attachmentLinkUrl;
+str = lexGenericAttachment.buttons[0].text;
+str = lexGenericAttachment.buttons[0].value;
+
+lexDialogAction.type === 'Close';
+lexDialogAction.type === 'ConfirmIntent';
+lexDialogAction.type === 'Delegate';
+lexDialogAction.type === 'ElicitIntent';
+lexDialogAction.type === 'ElicitSlot';
+
+lexDialogActionBase.message!.contentType === 'CustomPayload';
+lexDialogActionBase.message!.contentType === 'PlainText';
+lexDialogActionBase.message!.contentType === 'SSML';
+str = lexDialogActionBase.message!.content;
+num = lexDialogActionBase.responseCard!.version;
+lexDialogActionBase.responseCard!.contentType === 'application/vnd.amazonaws.card.generic';
+// $ExpectType LexGenericAttachment
+lexDialogActionBase.responseCard!.genericAttachments[0];
+
+lexDialogActionClose.type === 'Close';
+lexDialogActionClose.fulfillmentState === 'Failed';
+lexDialogActionClose.fulfillmentState === 'Fulfilled';
+
+lexDialogActionConfirmIntent.type === 'ConfirmIntent';
+str = lexDialogActionConfirmIntent.intentName;
+strOrNull = lexDialogActionConfirmIntent.slots['example'];
+
+lexDialogActionDelegate.type === 'Delegate';
+strOrNull = lexDialogActionDelegate.slots['example'];
+
+lexDialogActionElicitIntent.type === 'ElicitIntent';
+lexDialogActionElicitSlot.type === 'ElicitSlot';
+strOrNull = lexDialogActionElicitSlot.slots['example'];
+str = lexDialogActionElicitSlot.slotToElicit;
+str = lexDialogActionElicitSlot.intentName;
diff --git a/types/aws-lambda/test/s3-tests.ts b/types/aws-lambda/test/s3-tests.ts
new file mode 100644
index 0000000000..65cfa9b78d
--- /dev/null
+++ b/types/aws-lambda/test/s3-tests.ts
@@ -0,0 +1,102 @@
+import { Callback, Context, S3BatchEvent, S3BatchResult, S3CreateEvent, S3EventRecord, S3Handler } from "aws-lambda";
+
+// TODO: Update test to read event properties, like the user will
+let handler: S3Handler = async (event, context, callback) => {
+    callback(new Error());
+};
+
+// Test old event name
+handler = (event: S3CreateEvent, context: Context, cb: Callback<void>) => {};
+
+const record: S3EventRecord = {
+    eventVersion: '2.1',
+    eventSource: 'aws:s3',
+    awsRegion: 'us-east-1',
+    eventTime: '1970-01-01T00:00:00.000Z',
+    eventName: 'ObjectRestore:Completed',
+    userIdentity: {
+        principalId: 'AIDAJDPLRKLG7UEXAMPLE',
+    },
+    requestParameters: {
+        sourceIPAddress: '127.0.0.1',
+    },
+    responseElements: {
+        'x-amz-request-id': 'C3D13FE58DE4C810',
+        'x-amz-id-2': 'FMyUVURIY8/IgAtTv8xRjskZQpcIZ9KG4V5Wp6S7S/JRWeUWerMUE5JgHvANOjpD',
+    },
+    s3: {
+        s3SchemaVersion: '1.0',
+        configurationId: 'testConfigRule',
+        bucket: {
+            name: 'mybucket',
+            ownerIdentity: {
+                principalId: 'A3NL1KOZZKExample',
+            },
+            arn: 'arn:aws:s3:::mybucket',
+        },
+        object: {
+            key: 'HappyFace.jpg',
+            size: 1024,
+            eTag: 'd41d8cd98f00b204e9800998ecf8427e',
+            versionId: '096fKKXTRTtl3on89fVO.nfljtsv6qko',
+            sequencer: '0055AED6DCD90281E5',
+        },
+    },
+    glacierEventData: {
+        restoreEventData: {
+            lifecycleRestorationExpiryTime: '1970-01-01T00:00:00.000Z',
+            lifecycleRestoreStorageClass: 'glacier-deep-archive',
+        },
+    },
+};
+
+const event: S3CreateEvent = {
+    Records: [record],
+};
+
+/**
+ * S3 Batch Operations event
+ * https://docs.aws.amazon.com/AmazonS3/latest/dev/batch-ops-invoke-lambda.html
+ */
+const batchEvent: S3BatchEvent = {
+    invocationSchemaVersion: '1.0',
+    invocationId: 'foo_invocation_id',
+    job: { id: 'foo_job_id' },
+    tasks: [
+        {
+            taskId: '11111',
+            s3Key: 'example.json',
+            s3BucketArn: 'arn:aws:s3:::foo-bucket',
+            s3VersionId: null,
+        },
+        {
+            taskId: '11111',
+            s3Key: 'example.json',
+            s3BucketArn: 'arn:aws:s3:::foo-bucket',
+            s3VersionId: 'asdf',
+        },
+    ],
+};
+
+const batchResult: S3BatchResult = {
+    invocationSchemaVersion: '1.0',
+    treatMissingKeysAs: 'PermanentFailure',
+    invocationId: 'foo_invocation_id',
+    results: [
+        {
+            taskId: '11111',
+            resultCode: 'Succeeded',
+            resultString: 'foo',
+        },
+        {
+            taskId: '22222',
+            resultCode: 'TemporaryFailure',
+            resultString: 'Error: failure',
+        },
+        {
+            taskId: '33333',
+            resultCode: 'PermanentFailure',
+            resultString: 'Error: failure',
+        },
+    ],
+};
diff --git a/types/aws-lambda/test/sns-tests.ts b/types/aws-lambda/test/sns-tests.ts
new file mode 100644
index 0000000000..9235de7cff
--- /dev/null
+++ b/types/aws-lambda/test/sns-tests.ts
@@ -0,0 +1,29 @@
+import { SNSEventRecord, SNSHandler, SNSMessage, SNSMessageAttribute, SNSMessageAttributes } from "aws-lambda";
+
+const handler: SNSHandler = async (event, context, callback) => {
+    const record: SNSEventRecord = event.Records[num];
+
+    str = record.EventSource;
+    str = record.EventSubscriptionArn;
+    str = record.EventVersion;
+    const message: SNSMessage = record.Sns;
+
+    str = message.SignatureVersion;
+    str = message.Timestamp;
+    str = message.Signature;
+    str = message.SigningCertUrl;
+    str = message.MessageId;
+    str = message.Message;
+    const attributes: SNSMessageAttributes = message.MessageAttributes;
+    str = message.Type;
+    str = message.UnsubscribeUrl;
+    str = message.TopicArn;
+    str = message.Subject;
+
+    const attribute: SNSMessageAttribute = attributes[str];
+    str = attribute.Type;
+    str = attribute.Value;
+
+    callback();
+    callback(new Error());
+};
diff --git a/types/aws-lambda/test/sqs-tests.ts b/types/aws-lambda/test/sqs-tests.ts
new file mode 100644
index 0000000000..302ac03f9a
--- /dev/null
+++ b/types/aws-lambda/test/sqs-tests.ts
@@ -0,0 +1,44 @@
+import { SQSEvent, SQSHandler } from "aws-lambda";
+
+// TODO: Update test to read all event properties, like the user will.
+
+const handler: SQSHandler = async (event, context, callback) => {
+    str = event.Records[0].messageId;
+    anyObj = event.Records[0].body;
+    strOrUndefined = event.Records[0].messageAttributes.testAttr.stringValue;
+    strOrUndefined = event.Records[0].messageAttributes.testAttr.binaryValue;
+    str = event.Records[0].messageAttributes.testAttr.dataType;
+
+    callback();
+    callback(new Error());
+};
+
+// See https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-sqs
+const event: SQSEvent = {
+    Records: [
+        {
+            messageId: 'c80e8021-a70a-42c7-a470-796e1186f753',
+            receiptHandle: 'AQEBJQ+/u6NsnT5t8Q/VbVxgdUl4TMKZ5FqhksRdIQvLBhwNvADoBxYSOVeCBXdnS9P+',
+            body: '{"foo":"bar"}',
+            attributes: {
+                ApproximateReceiveCount: '3',
+                SentTimestamp: '1529104986221',
+                SenderId: '594035263019',
+                ApproximateFirstReceiveTimestamp: '1529104986230',
+            },
+            messageAttributes: {
+                testAttr: {
+                    stringValue: '100',
+                    binaryValue: 'base64Str',
+                    stringListValues: [],
+                    binaryListValues: [],
+                    dataType: 'Number',
+                },
+            },
+            md5OfBody: '9bb58f26192e4ba00f01e2e7b136bbd8',
+            eventSource: 'aws:sqs',
+            eventSourceARN: 'arn:aws:sqs:us-west-2:594035263019:NOTFIFOQUEUE',
+            awsRegion: 'us-west-2',
+        },
+    ],
+};
diff --git a/types/aws-lambda/trigger/alb.d.ts b/types/aws-lambda/trigger/alb.d.ts
new file mode 100644
index 0000000000..b93c2d6646
--- /dev/null
+++ b/types/aws-lambda/trigger/alb.d.ts
@@ -0,0 +1,32 @@
+import { Handler, Callback } from "../hander";
+
+export type ALBHandler = Handler<ALBEvent, ALBResult>;
+export type ALBCallback = Callback<ALBResult>;
+
+// https://docs.aws.amazon.com/elasticloadbalancing/latest/application/lambda-functions.html
+export interface ALBEventRequestContext {
+    elb: {
+        targetGroupArn: string;
+    };
+}
+
+export interface ALBEvent {
+    requestContext: ALBEventRequestContext;
+    httpMethod: string;
+    path: string;
+    queryStringParameters?: { [parameter: string]: string }; // URL encoded
+    headers?: { [header: string]: string };
+    multiValueQueryStringParameters?: { [parameter: string]: string[] }; // URL encoded
+    multiValueHeaders?: { [header: string]: string[] };
+    body: string | null;
+    isBase64Encoded: boolean;
+}
+
+export interface ALBResult {
+    statusCode: number;
+    statusDescription: string;
+    headers?: { [header: string]: boolean | number | string };
+    multiValueHeaders?: { [header: string]: Array<boolean | number | string> };
+    body?: string;
+    isBase64Encoded: boolean;
+}
diff --git a/types/aws-lambda/trigger/api-gateway-authorizer.d.ts b/types/aws-lambda/trigger/api-gateway-authorizer.d.ts
new file mode 100644
index 0000000000..761c4fb746
--- /dev/null
+++ b/types/aws-lambda/trigger/api-gateway-authorizer.d.ts
@@ -0,0 +1,88 @@
+import { APIGatewayEventRequestContext, AuthResponseContext } from "../common/api-gateway";
+import { Callback, Handler } from "../hander";
+
+export type CustomAuthorizerHandler = Handler<CustomAuthorizerEvent, CustomAuthorizerResult>;
+export type CustomAuthorizerCallback = Callback<CustomAuthorizerResult>;
+
+// API Gateway CustomAuthorizer "event"
+export interface CustomAuthorizerEvent {
+    type: string;
+    methodArn: string;
+    authorizationToken?: string;
+    resource?: string;
+    path?: string;
+    httpMethod?: string;
+    headers?: { [name: string]: string };
+    multiValueHeaders?: { [name: string]: string[] };
+    pathParameters?: { [name: string]: string } | null;
+    queryStringParameters?: { [name: string]: string } | null;
+    multiValueQueryStringParameters?: { [name: string]: string[] } | null;
+    stageVariables?: { [name: string]: string };
+    requestContext?: APIGatewayEventRequestContext;
+    domainName?: string;
+    apiId?: string;
+}
+
+/**
+ * API Gateway CustomAuthorizer AuthResponse.
+ * http://docs.aws.amazon.com/apigateway/latest/developerguide/use-custom-authorizer.html#api-gateway-custom-authorizer-output
+ */
+export interface CustomAuthorizerResult {
+    principalId: string;
+    policyDocument: PolicyDocument;
+    context?: AuthResponseContext;
+    usageIdentifierKey?: string;
+}
+export type AuthResponse = CustomAuthorizerResult;
+
+/**
+ * API Gateway CustomAuthorizer AuthResponse.PolicyDocument.
+ * https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-lambda-authorizer-output.html
+ * https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html#Condition
+ */
+export interface PolicyDocument {
+    Version: string;
+    Id?: string;
+    Statement: Statement[];
+}
+
+/**
+ * API Gateway CustomAuthorizer AuthResponse.PolicyDocument.Condition.
+ * https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-control-access-policy-language-overview.html
+ * https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html
+ */
+export interface ConditionBlock {
+    [condition: string]: Condition | Condition[];
+}
+
+export interface Condition {
+    [key: string]: string | string[];
+}
+
+/**
+ * API Gateway CustomAuthorizer AuthResponse.PolicyDocument.Statement.
+ * https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-control-access-policy-language-overview.html
+ * https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html
+ */
+export type Statement = BaseStatement & StatementAction & (StatementResource | StatementPrincipal);
+
+export interface BaseStatement {
+    Effect: string;
+    Sid?: string;
+    Condition?: ConditionBlock;
+}
+
+export type PrincipalValue = { [key: string]: string | string[] } | string | string[];
+export interface MaybeStatementPrincipal {
+    Principal?: PrincipalValue;
+    NotPrincipal?: PrincipalValue;
+}
+export interface MaybeStatementResource {
+    Resource?: string | string[];
+    NotResource?: string | string[];
+}
+export type StatementAction = { Action: string | string[] } | { NotAction: string | string[] };
+export type StatementResource = MaybeStatementPrincipal &
+    ({ Resource: string | string[] } | { NotResource: string | string[] });
+export type StatementPrincipal = MaybeStatementResource &
+    ({ Principal: PrincipalValue } | { NotPrincipal: PrincipalValue });
diff --git a/types/aws-lambda/trigger/api-gateway-proxy.d.ts b/types/aws-lambda/trigger/api-gateway-proxy.d.ts
new file mode 100644
index 0000000000..eb1890dc2a
--- /dev/null
+++ b/types/aws-lambda/trigger/api-gateway-proxy.d.ts
@@ -0,0 +1,38 @@
+import { APIGatewayEventRequestContext } from "../common/api-gateway";
+import { Callback, Handler } from "../hander";
+
+export type APIGatewayProxyHandler = Handler<APIGatewayProxyEvent, APIGatewayProxyResult>;
+export type APIGatewayProxyCallback = Callback<APIGatewayProxyResult>;
+
+export type ProxyHandler = APIGatewayProxyHandler; // Old name
+export type ProxyCallback = APIGatewayProxyCallback; // Old name
+export type APIGatewayEvent = APIGatewayProxyEvent; // Old name
+export type ProxyResult = APIGatewayProxyResult; // Old name
+
+// API Gateway "event"
+export interface APIGatewayProxyEvent {
+    body: string | null;
+    headers: { [name: string]: string };
+    multiValueHeaders: { [name: string]: string[] };
+    httpMethod: string;
+    isBase64Encoded: boolean;
+    path: string;
+    pathParameters: { [name: string]: string } | null;
+    queryStringParameters: { [name: string]: string } | null;
+    multiValueQueryStringParameters: { [name: string]: string[] } | null;
+    stageVariables: { [name: string]: string } | null;
+    requestContext: APIGatewayEventRequestContext;
+    resource: string;
+}
+
+export interface APIGatewayProxyResult {
+    statusCode: number;
+    headers?: {
+        [header: string]: boolean | number | string;
+    };
+    multiValueHeaders?: {
+        [header: string]: Array<boolean | number | string>;
+    };
+    body: string;
+    isBase64Encoded?: boolean;
+}
diff --git a/types/aws-lambda/trigger/cloudformation-custom-resource.d.ts b/types/aws-lambda/trigger/cloudformation-custom-resource.d.ts
new file mode 100644
index 0000000000..a3ebd11f0b
--- /dev/null
+++ b/types/aws-lambda/trigger/cloudformation-custom-resource.d.ts
@@ -0,0 +1,68 @@
+import { Handler } from "../hander";
+
+// Note, responses are *not* lambda results, they are sent to the event ResponseURL.
+export type CloudFormationCustomResourceHandler = Handler<CloudFormationCustomResourceEvent, void>;
+
+export type CloudFormationCustomResourceEvent =
+    | CloudFormationCustomResourceCreateEvent
+    | CloudFormationCustomResourceUpdateEvent
+    | CloudFormationCustomResourceDeleteEvent;
+
+export type CloudFormationCustomResourceResponse =
+    | CloudFormationCustomResourceSuccessResponse
+    | CloudFormationCustomResourceFailedResponse;
+
+/**
+ * CloudFormation Custom Resource event and response
+ * http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/crpg-ref.html
+ */
+export interface CloudFormationCustomResourceEventCommon {
+    ServiceToken: string;
+    ResponseURL: string;
+    StackId: string;
+    RequestId: string;
+    LogicalResourceId: string;
+    ResourceType: string;
+    ResourceProperties: {
+        ServiceToken: string;
+        [Key: string]: any;
+    };
+}
+
+export interface CloudFormationCustomResourceCreateEvent extends CloudFormationCustomResourceEventCommon {
+    RequestType: 'Create';
+}
+
+export interface CloudFormationCustomResourceUpdateEvent extends CloudFormationCustomResourceEventCommon {
+    RequestType: 'Update';
+    PhysicalResourceId: string;
+    OldResourceProperties: {
+        [Key: string]: any;
+    };
+}
+
+export interface CloudFormationCustomResourceDeleteEvent extends CloudFormationCustomResourceEventCommon {
+    RequestType: 'Delete';
+    PhysicalResourceId: string;
+}
+
+export interface CloudFormationCustomResourceResponseCommon {
+    PhysicalResourceId: string;
+    StackId: string;
+    RequestId: string;
+    LogicalResourceId: string;
+    Data?: {
+        [Key: string]: any;
+    };
+    NoEcho?: boolean;
+}
+
+export interface CloudFormationCustomResourceSuccessResponse extends CloudFormationCustomResourceResponseCommon {
+    Status: 'SUCCESS';
+    Reason?: string;
+}
+
+export interface CloudFormationCustomResourceFailedResponse extends CloudFormationCustomResourceResponseCommon {
+    Status: 'FAILED';
+    Reason: string;
+}
diff --git a/types/aws-lambda/trigger/cloudfront-request.d.ts b/types/aws-lambda/trigger/cloudfront-request.d.ts
new file mode 100644
index 0000000000..8a4d0e5269
--- /dev/null
+++ b/types/aws-lambda/trigger/cloudfront-request.d.ts
@@ -0,0 +1,20 @@
+import { CloudFrontEvent, CloudFrontRequest, CloudFrontResultResponse } from "../common/cloudfront";
+import { Handler, Callback } from "../hander";
+
+export type CloudFrontRequestHandler = Handler<CloudFrontRequestEvent, CloudFrontRequestResult>;
+export type CloudFrontRequestCallback = Callback<CloudFrontRequestResult>;
+
+/**
+ * CloudFront viewer request or origin request event
+ *
+ * https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html#lambda-event-structure-request
+ */
+export interface CloudFrontRequestEvent {
+    Records: Array<{
+        cf: CloudFrontEvent & {
+            request: CloudFrontRequest;
+        };
+    }>;
+}
+
+export type CloudFrontRequestResult = undefined | null | CloudFrontResultResponse | CloudFrontRequest;
diff --git a/types/aws-lambda/trigger/cloudfront-response.d.ts b/types/aws-lambda/trigger/cloudfront-response.d.ts
new file mode 100644
index 0000000000..d228d3d752
--- /dev/null
+++ b/types/aws-lambda/trigger/cloudfront-response.d.ts
@@ -0,0 +1,21 @@
+import { CloudFrontEvent, CloudFrontRequest, CloudFrontResponse, CloudFrontResultResponse } from "../common/cloudfront";
+import { Callback, Handler } from "../hander";
+
+export type CloudFrontResponseHandler = Handler<CloudFrontResponseEvent, CloudFrontResponseResult>;
+export type CloudFrontResponseCallback = Callback<CloudFrontResponseResult>;
+
+/**
+ * CloudFront viewer response or origin response event
+ *
+ * https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html#lambda-event-structure-response
+ */
+export interface CloudFrontResponseEvent {
+    Records: Array<{
+        cf: CloudFrontEvent & {
+            readonly request: Pick<CloudFrontRequest, Exclude<keyof CloudFrontRequest, 'body'>>;
+            response: CloudFrontResponse;
+        };
+    }>;
+}
+
+export type CloudFrontResponseResult = undefined | null | CloudFrontResultResponse;
diff --git a/types/aws-lambda/trigger/cloudwatch-events.d.ts b/types/aws-lambda/trigger/cloudwatch-events.d.ts
new file mode 100644
index 0000000000..4ddc681fb2
--- /dev/null
+++ b/types/aws-lambda/trigger/cloudwatch-events.d.ts
@@ -0,0 +1,19 @@
+import { Handler } from "../hander";
+
+export type ScheduledHandler = Handler<ScheduledEvent, void>;
+
+// TODO: generic cloudwatch event types.
+
+/**
+ * https://docs.aws.amazon.com/lambda/latest/dg/with-scheduled-events.html
+ */
+export interface ScheduledEvent {
+    account: string;
+    region: string;
+    detail: any;
+    'detail-type': string;
+    source: string;
+    time: string;
+    id: string;
+    resources: string[];
+}
diff --git a/types/aws-lambda/trigger/cloudwatch-logs.d.ts b/types/aws-lambda/trigger/cloudwatch-logs.d.ts
new file mode 100644
index 0000000000..1912b42ee3
--- /dev/null
+++ b/types/aws-lambda/trigger/cloudwatch-logs.d.ts
@@ -0,0 +1,33 @@
+import { Handler } from "../hander";
+
+export type CloudWatchLogsHandler = Handler<CloudWatchLogsEvent, void>;
+
+/**
+ * See http://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-cloudwatch-logs
+ */
+export interface CloudWatchLogsEvent {
+    awslogs: CloudWatchLogsEventData;
+}
+
+export interface CloudWatchLogsEventData {
+    data: string;
+}
+
+export interface CloudWatchLogsDecodedData {
+    owner: string;
+    logGroup: string;
+    logStream: string;
+    subscriptionFilters: string[];
+    messageType: string;
+    logEvents: CloudWatchLogsLogEvent[];
+}
+
+/**
+ * See http://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/SubscriptionFilters.html#LambdaFunctionExample
+ */
+export interface CloudWatchLogsLogEvent {
+    id: string;
+    timestamp: number;
+    message: string;
+    extractedFields?: { [key: string]: string };
+}
diff --git a/types/aws-lambda/trigger/codepipeline-cloudwatch-action.d.ts b/types/aws-lambda/trigger/codepipeline-cloudwatch-action.d.ts
new file mode 100644
index 0000000000..083da87bba
--- /dev/null
+++ b/types/aws-lambda/trigger/codepipeline-cloudwatch-action.d.ts
@@ -0,0 +1,31 @@
+import { Handler } from "../hander";
+
+export type CodePipelineCloudWatchActionHandler = Handler<CodePipelineCloudWatchActionEvent, void>;
+
+export type CodePipelineActionCategory = 'Approval' | 'Build' | 'Deploy' | 'Invoke' | 'Source' | 'Test';
+export type CodePipelineActionState = 'STARTED' | 'SUCCEEDED' | 'FAILED' | 'CANCELED';
+
+export interface CodePipelineCloudWatchActionEvent {
+    version: string;
+    id: string;
+    'detail-type': 'CodePipeline Action Execution State Change';
+    source: 'aws.codepipeline';
+    account: string;
+    time: string;
+    region: string;
+    resources: string[];
+    detail: {
+        pipeline: string;
+        version: number;
+        'execution-id': string;
+        stage: string;
+        action: string;
+        state: CodePipelineActionState;
+        type: {
+            owner: 'AWS' | 'Custom' | 'ThirdParty';
+            category: CodePipelineActionCategory;
+            provider: string;
+            version: number;
+        };
+    };
+}
diff --git a/types/aws-lambda/trigger/codepipeline-cloudwatch-pipeline.d.ts b/types/aws-lambda/trigger/codepipeline-cloudwatch-pipeline.d.ts
new file mode 100644
index 0000000000..1d8da08cf7
--- /dev/null
+++ b/types/aws-lambda/trigger/codepipeline-cloudwatch-pipeline.d.ts
@@ -0,0 +1,32 @@
+import { Handler } from "../hander";
+
+export type CodePipelineCloudWatchPipelineHandler = Handler<CodePipelineCloudWatchPipelineEvent, void>;
+
+export type CodePipelineState = 'STARTED' | 'SUCCEEDED' | 'RESUMED' | 'FAILED' | 'CANCELED' | 'SUPERSEDED';
+
+/**
+ * CodePipeline CloudWatch Events
+ * https://docs.aws.amazon.com/codepipeline/latest/userguide/detect-state-changes-cloudwatch-events.html
+ *
+ * The above CodePipelineEvent is when a lambda is invoked by a CodePipeline.
+ * These events are when you subscribe to CodePipeline events in CloudWatch.
+ *
+ * Their documentation says that detail.version is a string, but it is actually an integer
+ */
+
+export interface CodePipelineCloudWatchPipelineEvent {
+    version: string;
+    id: string;
+    'detail-type': 'CodePipeline Pipeline Execution State Change';
+    source: 'aws.codepipeline';
+    account: string;
+    time: string;
+    region: string;
+    resources: string[];
+    detail: {
+        pipeline: string;
+        version: number;
+        state: CodePipelineState;
+        'execution-id': string;
+    };
+}
diff --git a/types/aws-lambda/trigger/codepipeline-cloudwatch-stage.d.ts b/types/aws-lambda/trigger/codepipeline-cloudwatch-stage.d.ts
new file mode 100644
index 0000000000..9f0bdcf0d1
--- /dev/null
+++ b/types/aws-lambda/trigger/codepipeline-cloudwatch-stage.d.ts
@@ -0,0 +1,23 @@
+import { Handler } from "../hander";
+
+export type CodePipelineCloudWatchStageHandler = Handler<CodePipelineCloudWatchStageEvent, void>;
+
+export type CodePipelineStageState = 'STARTED' | 'SUCCEEDED' | 'RESUMED' | 'FAILED' | 'CANCELED';
+
+export interface CodePipelineCloudWatchStageEvent {
+    version: string;
+    id: string;
+    'detail-type': 'CodePipeline Stage Execution State Change';
+    source: 'aws.codepipeline';
+    account: string;
+    time: string;
+    region: string;
+    resources: string[];
+    detail: {
+        pipeline: string;
+        version: number;
+        'execution-id': string;
+        stage: string;
+        state: CodePipelineStageState;
+    };
+}
diff --git a/types/aws-lambda/trigger/codepipeline-cloudwatch.d.ts b/types/aws-lambda/trigger/codepipeline-cloudwatch.d.ts
new file mode 100644
index 0000000000..2235ddf4bb
--- /dev/null
+++ b/types/aws-lambda/trigger/codepipeline-cloudwatch.d.ts
@@ -0,0 +1,11 @@
+import { Handler } from "../hander";
+import { CodePipelineCloudWatchActionEvent } from "./codepipeline-cloudwatch-action";
+import { CodePipelineCloudWatchPipelineEvent } from "./codepipeline-cloudwatch-pipeline";
+import { CodePipelineCloudWatchStageEvent } from "./codepipeline-cloudwatch-stage";
+
+export type CodePipelineCloudWatchHandler = Handler<CodePipelineCloudWatchEvent, void>;
+
+export type CodePipelineCloudWatchEvent =
+    | CodePipelineCloudWatchPipelineEvent
+    | CodePipelineCloudWatchStageEvent
+    | CodePipelineCloudWatchActionEvent;
diff --git a/types/aws-lambda/trigger/codepipeline.d.ts b/types/aws-lambda/trigger/codepipeline.d.ts
new file mode 100644
index 0000000000..9eb38a2db0
--- /dev/null
+++ b/types/aws-lambda/trigger/codepipeline.d.ts
@@ -0,0 +1,55 @@
+import { Handler } from "../hander";
+
+export type CodePipelineHandler = Handler<CodePipelineEvent, void>;
+
+/**
+ * CodePipeline events
+ * https://docs.aws.amazon.com/codepipeline/latest/userguide/actions-invoke-lambda-function.html
+ */
+export interface S3ArtifactLocation {
+    bucketName: string;
+    objectKey: string;
+}
+export interface S3ArtifactStore {
+    type: 'S3';
+    s3Location: S3ArtifactLocation;
+}
+
+export type ArtifactLocation = S3ArtifactStore;
+
+export interface Artifact {
+    name: string;
+    revision: string | null;
+    location: ArtifactLocation;
+}
+
+export interface Credentials {
+    accessKeyId: string;
+    secretAccessKey: string;
+    sessionToken?: string;
+}
+
+export interface EncryptionKey {
+    type: string;
+    id: string;
+}
+
+export interface CodePipelineEvent {
+    'CodePipeline.job': {
+        id: string;
+        accountId: string;
+        data: {
+            actionConfiguration: {
+                configuration: {
+                    FunctionName: string;
+                    UserParameters: string;
+                };
+            };
+            inputArtifacts: Artifact[];
+            outputArtifacts: Artifact[];
+            artifactCredentials: Credentials;
+            encryptionKey?: EncryptionKey & { type: 'KMS' };
+            continuationToken?: string;
+        };
+    };
+}
diff --git a/types/aws-lambda/trigger/cognito-user-pool-trigger.d.ts b/types/aws-lambda/trigger/cognito-user-pool-trigger.d.ts
new file mode 100644
index 0000000000..fe849fa514
--- /dev/null
+++ b/types/aws-lambda/trigger/cognito-user-pool-trigger.d.ts
@@ -0,0 +1,99 @@
+import { Handler } from "../hander";
+
+// Result type is weird: docs and samples say to return the mutated event, but it only requires an object
+// with a "response" field, the type of which is specific to the event.triggerType. Leave as any for now.
+export type CognitoUserPoolTriggerHandler = Handler<CognitoUserPoolTriggerEvent>;
+// TODO: Different event/handler types for each event trigger so we can type the result?
+
+/**
+ * Cognito User Pool event
+ * http://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-identity-pools-working-with-aws-lambda-triggers.html
+ */
+export interface CognitoUserPoolTriggerEvent {
+    version: number;
+    triggerSource:
+        | 'PreSignUp_SignUp'
+        | 'PreSignUp_ExternalProvider'
+        | 'PostConfirmation_ConfirmSignUp'
+        | 'PreAuthentication_Authentication'
+        | 'PostAuthentication_Authentication'
+        | 'CustomMessage_SignUp'
+        | 'CustomMessage_AdminCreateUser'
+        | 'CustomMessage_ResendCode'
+        | 'CustomMessage_ForgotPassword'
+        | 'CustomMessage_UpdateUserAttribute'
+        | 'CustomMessage_VerifyUserAttribute'
+        | 'CustomMessage_Authentication'
+        | 'DefineAuthChallenge_Authentication'
+        | 'CreateAuthChallenge_Authentication'
+        | 'VerifyAuthChallengeResponse_Authentication'
+        | 'PreSignUp_AdminCreateUser'
+        | 'PostConfirmation_ConfirmForgotPassword'
+        | 'TokenGeneration_HostedAuth'
+        | 'TokenGeneration_Authentication'
+        | 'TokenGeneration_NewPasswordChallenge'
+        | 'TokenGeneration_AuthenticateDevice'
+        | 'TokenGeneration_RefreshTokens'
+        | 'UserMigration_Authentication'
+        | 'UserMigration_ForgotPassword';
+    region: string;
+    userPoolId: string;
+    userName?: string;
+    callerContext: {
+        awsSdkVersion: string;
+        clientId: string;
+    };
+    request: {
+        userAttributes: { [key: string]: string };
+        validationData?: { [key: string]: string };
+        codeParameter?: string;
+        linkParameter?: string;
+        usernameParameter?: string;
+        newDeviceUsed?: boolean;
+        session?: Array<{
+            challengeName:
+                | 'CUSTOM_CHALLENGE'
+                | 'PASSWORD_VERIFIER'
+                | 'SMS_MFA'
+                | 'DEVICE_SRP_AUTH'
+                | 'DEVICE_PASSWORD_VERIFIER'
+                | 'ADMIN_NO_SRP_AUTH';
+            challengeResult: boolean;
+            challengeMetadata?: string;
+        }>;
+        challengeName?: string;
+        privateChallengeParameters?: { [key: string]: string };
+        challengeAnswer?: string;
+        password?: string;
+    };
+    response: {
+        autoConfirmUser?: boolean;
+        autoVerifyPhone?: boolean;
+        autoVerifyEmail?: boolean;
+        smsMessage?: string;
+        emailMessage?: string;
+        emailSubject?: string;
+        challengeName?: string;
+        issueTokens?: boolean;
+        failAuthentication?: boolean;
+        publicChallengeParameters?: { [key: string]: string };
+        privateChallengeParameters?: { [key: string]: string };
+        challengeMetadata?: string;
+        answerCorrect?: boolean;
+        userAttributes?: { [key: string]: string };
+        finalUserStatus?: 'CONFIRMED' | 'RESET_REQUIRED';
+        messageAction?: 'SUPPRESS';
+        desiredDeliveryMediums?: Array<'EMAIL' | 'SMS'>;
+        forceAliasCreation?: boolean;
+        claimsOverrideDetails?: {
+            claimsToAddOrOverride?: { [key: string]: string };
+            claimsToSuppress?: string[];
+            groupOverrideDetails?: null | {
+                groupsToOverride?: string[];
+                iamRolesToOverride?: string[];
+                preferredRole?: string;
+            };
+        };
+    };
+}
+export type CognitoUserPoolEvent = CognitoUserPoolTriggerEvent;
diff --git a/types/aws-lambda/trigger/dynamodb-stream.d.ts b/types/aws-lambda/trigger/dynamodb-stream.d.ts
new file mode 100644
index 0000000000..486523cb4b
--- /dev/null
+++ b/types/aws-lambda/trigger/dynamodb-stream.d.ts
@@ -0,0 +1,45 @@
+import { Handler } from "../hander";
+
+export type DynamoDBStreamHandler = Handler<DynamoDBStreamEvent, void>;
+
+// http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_streams_AttributeValue.html
+export interface AttributeValue {
+    B?: string;
+    BS?: string[];
+    BOOL?: boolean;
+    L?: AttributeValue[];
+    M?: { [id: string]: AttributeValue };
+    N?: string;
+    NS?: string[];
+    NULL?: boolean;
+    S?: string;
+    SS?: string[];
+}
+
+// http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_streams_StreamRecord.html
+export interface StreamRecord {
+    ApproximateCreationDateTime?: number;
+    Keys?: { [key: string]: AttributeValue };
+    NewImage?: { [key: string]: AttributeValue };
+    OldImage?: { [key: string]: AttributeValue };
+    SequenceNumber?: string;
+    SizeBytes?: number;
+    StreamViewType?: 'KEYS_ONLY' | 'NEW_IMAGE' | 'OLD_IMAGE' | 'NEW_AND_OLD_IMAGES';
+}
+
+// http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_streams_Record.html
+export interface DynamoDBRecord {
+    awsRegion?: string;
+    dynamodb?: StreamRecord;
+    eventID?: string;
+    eventName?: 'INSERT' | 'MODIFY' | 'REMOVE';
+    eventSource?: string;
+    eventSourceARN?: string;
+    eventVersion?: string;
+    userIdentity?: any;
+}
+
+// http://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-ddb-update
+export interface DynamoDBStreamEvent {
+    Records: DynamoDBRecord[];
+}
diff --git a/types/aws-lambda/trigger/kinesis-firehose-transformation.d.ts b/types/aws-lambda/trigger/kinesis-firehose-transformation.d.ts
new file mode 100644
index 0000000000..020ae0d907
--- /dev/null
+++ b/types/aws-lambda/trigger/kinesis-firehose-transformation.d.ts
@@ -0,0 +1,45 @@
+import { Callback, Handler } from "../hander";
+
+export type FirehoseTransformationHandler = Handler<FirehoseTransformationEvent, FirehoseTransformationResult>;
+export type FirehoseTransformationCallback = Callback<FirehoseTransformationResult>;
+
+// Kinesis Data Firehose Event
+// https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-kinesis-firehose
+// https://docs.aws.amazon.com/firehose/latest/dev/data-transformation.html
+// https://aws.amazon.com/blogs/compute/amazon-kinesis-firehose-data-transformation-with-aws-lambda/
+// Examples in the lambda blueprints
+export interface FirehoseTransformationEvent {
+    invocationId: string;
+    deliveryStreamArn: string;
+    region: string;
+    records: FirehoseTransformationEventRecord[];
+}
+
+export interface FirehoseTransformationEventRecord {
+    recordId: string;
+    approximateArrivalTimestamp: number;
+    /** Base64 encoded */
+    data: string;
+    kinesisRecordMetadata?: FirehoseRecordMetadata;
+}
+
+export interface FirehoseRecordMetadata {
+    shardId: string;
+    partitionKey: string;
+    approximateArrivalTimestamp: string;
+    sequenceNumber: string;
+    subsequenceNumber: string;
+}
+
+export type FirehoseRecordTransformationStatus = 'Ok' | 'Dropped' | 'ProcessingFailed';
+
+export interface FirehoseTransformationResultRecord {
+    recordId: string;
+    result: FirehoseRecordTransformationStatus;
+    /** Encode in Base64 */
+    data: string;
+}
+
+export interface FirehoseTransformationResult {
+    records: FirehoseTransformationResultRecord[];
+}
diff --git a/types/aws-lambda/trigger/kinesis-stream.d.ts b/types/aws-lambda/trigger/kinesis-stream.d.ts
new file mode 100644
index 0000000000..54acd6ea49
--- /dev/null
+++ b/types/aws-lambda/trigger/kinesis-stream.d.ts
@@ -0,0 +1,28 @@
+import { Handler } from "../hander";
+
+export type KinesisStreamHandler = Handler<KinesisStreamEvent, void>;
+
+// Kinesis Streams
+// https://docs.aws.amazon.com/lambda/latest/dg/eventsources.html#eventsources-kinesis-streams
+export interface KinesisStreamRecordPayload {
+    approximateArrivalTimestamp: number;
+    data: string;
+    kinesisSchemaVersion: string;
+    partitionKey: string;
+    sequenceNumber: string;
+}
+
+export interface KinesisStreamRecord {
+    awsRegion: string;
+    eventID: string;
+    eventName: string;
+    eventSource: string;
+    eventSourceARN: string;
+    eventVersion: string;
+    invokeIdentityArn: string;
+    kinesis: KinesisStreamRecordPayload;
+}
+
+export interface KinesisStreamEvent {
+    Records: KinesisStreamRecord[];
+}
diff --git a/types/aws-lambda/trigger/lex.d.ts b/types/aws-lambda/trigger/lex.d.ts
new file mode 100644
index 0000000000..d52eebdc98
--- /dev/null
+++ b/types/aws-lambda/trigger/lex.d.ts
@@ -0,0 +1,103 @@
+import { Callback, Handler } from "../hander";
+
+export type LexHandler = Handler<LexEvent, LexResult>;
+export type LexCallback = Callback<LexResult>;
+
+// Lex
+// https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html#supported-event-source-lex
+export interface LexEvent {
+    currentIntent: {
+        name: string;
+        slots: { [name: string]: string | null };
+        slotDetails: LexSlotDetails;
+        confirmationStatus: 'None' | 'Confirmed' | 'Denied';
+    };
+    bot: {
+        name: string;
+        alias: string;
+        version: string;
+    };
+    userId: string;
+    inputTranscript: string;
+    invocationSource: 'DialogCodeHook' | 'FulfillmentCodeHook';
+    outputDialogMode: 'Text' | 'Voice';
+    messageVersion: '1.0';
+    sessionAttributes: { [key: string]: string };
+    requestAttributes: { [key: string]: string } | null;
+}
+
+export interface LexSlotResolution {
+    value: string;
+}
+
+export interface LexSlotDetails {
+    [name: string]: {
+        // The following line only works in TypeScript Version: 3.0, The array should have at least 1 and no more than 5 items
+        // resolutions: [LexSlotResolution, LexSlotResolution?, LexSlotResolution?, LexSlotResolution?, LexSlotResolution?];
+        resolutions: LexSlotResolution[];
+        originalValue: string;
+    };
+}
+
+export interface LexGenericAttachment {
+    title: string;
+    subTitle: string;
+    imageUrl: string;
+    attachmentLinkUrl: string;
+    buttons: Array<{
+        text: string;
+        value: string;
+    }>;
+}
+
+export interface LexDialogActionBase {
+    type: 'Close' | 'ElicitIntent' | 'ElicitSlot' | 'ConfirmIntent';
+    message?: {
+        contentType: 'PlainText' | 'SSML' | 'CustomPayload';
+        content: string;
+    };
+    responseCard?: {
+        version: number;
+        contentType: 'application/vnd.amazonaws.card.generic';
+        genericAttachments: LexGenericAttachment[];
+    };
+}
+
+export interface LexDialogActionClose extends LexDialogActionBase {
+    type: 'Close';
+    fulfillmentState: 'Fulfilled' | 'Failed';
+}
+
+export interface LexDialogActionElicitIntent extends LexDialogActionBase {
+    type: 'ElicitIntent';
+}
+
+export interface LexDialogActionElicitSlot extends LexDialogActionBase {
+    type: 'ElicitSlot';
+    intentName: string;
+    slots: { [name: string]: string | null };
+    slotToElicit: string;
+}
+
+export interface LexDialogActionConfirmIntent extends LexDialogActionBase {
+    type: 'ConfirmIntent';
+    intentName: string;
+    slots: { [name: string]: string | null };
+}
+
+export interface LexDialogActionDelegate {
+    type: 'Delegate';
+    slots: { [name: string]: string | null };
+}
+
+export type LexDialogAction =
+    | LexDialogActionClose
+    | LexDialogActionElicitIntent
+    | LexDialogActionElicitSlot
+    | LexDialogActionConfirmIntent
+    | LexDialogActionDelegate;
+
+export interface LexResult {
+    sessionAttributes?: { [key: string]: string };
+    dialogAction: LexDialogAction;
+}
diff --git a/types/aws-lambda/trigger/s3-batch.d.ts b/types/aws-lambda/trigger/s3-batch.d.ts
new file mode 100644
index 0000000000..2fd1d1e464
--- /dev/null
+++ b/types/aws-lambda/trigger/s3-batch.d.ts
@@ -0,0 +1,41 @@
+import { Handler, Callback } from "../hander";
+
+/**
+ * S3 Batch Operations event
+ * https://docs.aws.amazon.com/AmazonS3/latest/dev/batch-ops-invoke-lambda.html
+ */
+export type S3BatchHandler = Handler<S3BatchEvent, S3BatchResult>;
+export type S3BatchCallback = Callback<S3BatchResult>;
+
+export interface S3BatchEvent {
+    invocationSchemaVersion: string;
+    invocationId: string;
+    job: S3BatchEventJob;
+    tasks: S3BatchEventTask[];
+}
+
+export interface S3BatchEventJob {
+    id: string;
+}
+
+export interface S3BatchEventTask {
+    taskId: string;
+    s3Key: string;
+    s3VersionId: string | null;
+    s3BucketArn: string;
+}
+
+export interface S3BatchResult {
+    invocationSchemaVersion: string;
+    treatMissingKeysAs: S3BatchResultResultCode;
+    invocationId: string;
+    results: S3BatchResultResult[];
+}
+
+export type S3BatchResultResultCode = 'Succeeded' | 'TemporaryFailure' | 'PermanentFailure';
+
+export interface S3BatchResultResult {
+    taskId: string;
+    resultCode: S3BatchResultResultCode;
+    resultString: string;
+}
diff --git a/types/aws-lambda/trigger/s3.d.ts b/types/aws-lambda/trigger/s3.d.ts
new file mode 100644
index 0000000000..4d48c13a6a
--- /dev/null
+++ b/types/aws-lambda/trigger/s3.d.ts
@@ -0,0 +1,60 @@
+import { Handler } from "../hander";
+
+export type S3Handler = Handler<S3Event, void>;
+
+/**
+ * S3Create event
+ * https://docs.aws.amazon.com/AmazonS3/latest/dev/notification-content-structure.html
+ */
+
+export interface S3EventRecordGlacierRestoreEventData {
+    lifecycleRestorationExpiryTime: string;
+    lifecycleRestoreStorageClass: string;
+}
+
+export interface S3EventRecordGlacierEventData {
+    restoreEventData: S3EventRecordGlacierRestoreEventData;
+}
+
+export interface S3EventRecord {
+    eventVersion: string;
+    eventSource: string;
+    awsRegion: string;
+    eventTime: string;
+    eventName: string;
+    userIdentity: {
+        principalId: string;
+    };
+    requestParameters: {
+        sourceIPAddress: string;
+    };
+    responseElements: {
+        'x-amz-request-id': string;
+        'x-amz-id-2': string;
+    };
+    s3: {
+        s3SchemaVersion: string;
+        configurationId: string;
+        bucket: {
+            name: string;
+            ownerIdentity: {
+                principalId: string;
+            };
+            arn: string;
+        };
+        object: {
+            key: string;
+            size: number;
+            eTag: string;
+            versionId?: string;
+            sequencer: string;
+        };
+    };
+    glacierEventData?: S3EventRecordGlacierEventData;
+}
+
+export interface S3Event {
+    Records: S3EventRecord[];
+}
+
+export type S3CreateEvent = S3Event; // old name
diff --git a/types/aws-lambda/trigger/sns.d.ts b/types/aws-lambda/trigger/sns.d.ts
new file mode 100644
index 0000000000..6c6eac4a6b
--- /dev/null
+++ b/types/aws-lambda/trigger/sns.d.ts
@@ -0,0 +1,38 @@
+import { Handler } from "../hander";
+
+export type SNSHandler = Handler<SNSEvent, void>;
+
+// SNS "event"
+export interface SNSMessageAttribute {
+    Type: string;
+    Value: string;
+}
+
+export interface SNSMessageAttributes {
+    [name: string]: SNSMessageAttribute;
+}
+
+export interface SNSMessage {
+    SignatureVersion: string;
+    Timestamp: string;
+    Signature: string;
+    SigningCertUrl: string;
+    MessageId: string;
+    Message: string;
+    MessageAttributes: SNSMessageAttributes;
+    Type: string;
+    UnsubscribeUrl: string;
+    TopicArn: string;
+    Subject: string;
+}
+
+export interface SNSEventRecord {
+    EventVersion: string;
+    EventSubscriptionArn: string;
+    EventSource: string;
+    Sns: SNSMessage;
+}
+
+export interface SNSEvent {
+    Records: SNSEventRecord[];
+}
diff --git a/types/aws-lambda/trigger/sqs.d.ts b/types/aws-lambda/trigger/sqs.d.ts
new file mode 100644
index 0000000000..9c23a9f280
--- /dev/null
+++ b/types/aws-lambda/trigger/sqs.d.ts
@@ -0,0 +1,42 @@
+import { Handler } from "../hander";
+
+export type SQSHandler = Handler<SQSEvent, void>;
+
+// SQS
+// https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html#supported-event-source-sqs
+export interface SQSRecord {
+    messageId: string;
+    receiptHandle: string;
+    body: string;
+    attributes: SQSRecordAttributes;
+    messageAttributes: SQSMessageAttributes;
+    md5OfBody: string;
+    eventSource: string;
+    eventSourceARN: string;
+    awsRegion: string;
+}
+
+export interface SQSEvent {
+    Records: SQSRecord[];
+}
+
+export interface SQSRecordAttributes {
+    ApproximateReceiveCount: string;
+    SentTimestamp: string;
+    SenderId: string;
+    ApproximateFirstReceiveTimestamp: string;
+}
+
+export type SQSMessageAttributeDataType = 'String' | 'Number' | 'Binary' | string;
+
+export interface SQSMessageAttribute {
+    stringValue?: string;
+    binaryValue?: string;
+    stringListValues: never[]; // Not implemented. Reserved for future use.
+    binaryListValues: never[]; // Not implemented. Reserved for future use.
+    dataType: SQSMessageAttributeDataType;
+}
+
+export interface SQSMessageAttributes {
+    [name: string]: SQSMessageAttribute;
+}
diff --git a/types/aws-lambda/tsconfig.json b/types/aws-lambda/tsconfig.json
index 79e058b7ab..598e7b0fba 100644
--- a/types/aws-lambda/tsconfig.json
+++ b/types/aws-lambda/tsconfig.json
@@ -18,6 +18,19 @@
     },
     "files": [
         "index.d.ts",
-        "aws-lambda-tests.ts"
+        "aws-lambda-tests.ts",
+        "test/alb-tests.ts",
+        "test/api-gateway-tests.ts",
+        "test/cloudformation-tests.ts",
+        "test/cloudfront-tests.ts",
+        "test/cloudwatch-tests.ts",
+        "test/codepipeline-tests.ts",
+        "test/cognito-tests.ts",
+        "test/dynamodb-tests.ts",
+        "test/kinesis-tests.ts",
+        "test/lex-tests.ts",
+        "test/s3-tests.ts",
+        "test/sns-tests.ts",
+        "test/sqs-tests.ts"
     ]
-}
\ No newline at end of file
+}
diff --git a/types/aws-lambda/tslint.json b/types/aws-lambda/tslint.json
index f6fabe4180..c2d75e690a 100644
--- a/types/aws-lambda/tslint.json
+++ b/types/aws-lambda/tslint.json
@@ -1,8 +1,8 @@
 {
     "extends": "dtslint/dt.json",
     "rules": {
-        // TODO
-        "npm-naming": false,
-        "dt-header": false
+        // This is needed because there's an unrelated aws-lambda package on NPM,
+        // and DTS is complaining that we're referring to a non-existing version.
+        "npm-naming": false
     }
 }