diff --git a/types/react-reconciler/ReactElementType.d.ts b/types/react-reconciler/ReactElementType.d.ts
deleted file mode 100644
index f30d70586e..0000000000
--- a/types/react-reconciler/ReactElementType.d.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-export interface Source {
-    fileName: string;
-    lineNumber: number;
-}
diff --git a/types/react-reconciler/ReactFiber.d.ts b/types/react-reconciler/ReactFiber.d.ts
deleted file mode 100644
index 6ea29c798b..0000000000
--- a/types/react-reconciler/ReactFiber.d.ts
+++ /dev/null
@@ -1,130 +0,0 @@
-import { Source } from './ReactElementType';
-import { ExpirationTime } from './ReactFiberExpirationTime';
-import { ContextDependency } from './ReactFiberNewContext';
-import { SideEffectTag } from './ReactSideEffectTags';
-import { TypeOfMode } from './ReactTypeOfMode';
-import { RefObject } from './ReactTypes';
-import { UpdateQueue } from './ReactUpdateQueue';
-import { WorkTag } from './ReactWorkTags';
-
-// A Fiber is work on a Component that needs to be done or was done. There can
-// be more than one per component.
-export interface Fiber {
-    // These first fields are conceptually members of an Instance. This used to
-    // be split into a separate type and intersected with the other Fiber fields,
-    // but until Flow fixes its intersection bugs, we've merged them into a
-    // single type.
-
-    // An Instance is shared between all versions of a component. We can easily
-    // break this out into a separate object to avoid copying so much to the
-    // alternate versions of the tree. We put this on a single object for now to
-    // minimize the number of objects created during the initial render.
-
-    // Tag identifying the type of fiber.
-    tag: WorkTag;
-
-    // Unique identifier of this child.
-    key: null | string;
-
-    // The function/class/module associated with this fiber.
-    type: any;
-
-    // The local state associated with this fiber.
-    stateNode: any;
-
-    // Conceptual aliases
-    // parent : Instance -> return The parent happens to be the same as the
-    // return fiber since we've merged the fiber and instance.
-
-    // Remaining fields belong to Fiber
-
-    // The Fiber to return to after finishing processing this one.
-    // This is effectively the parent, but there can be multiple parents (two)
-    // so this is only the parent of the thing we're currently processing.
-    // It is conceptually the same as the return address of a stack frame.
-    return: Fiber | null;
-
-    // Singly Linked List Tree Structure.
-    child: Fiber | null;
-    sibling: Fiber | null;
-    index: number;
-
-    // The ref last used to attach this node.
-    // I'll avoid adding an owner field for prod and model that as functions.
-    ref: null | (((handle: any) => void) & { _stringRef: string | null | undefined }) | RefObject;
-
-    // Input is the data coming into process this fiber. Arguments. Props.
-    pendingProps: any; // This type will be more specific once we overload the tag.
-    memoizedProps: any; // The props used to create the output.
-
-    // A queue of state updates and callbacks.
-    updateQueue: UpdateQueue<any> | null;
-
-    // The state used to create the output
-    memoizedState: any;
-
-    // A linked-list of contexts that this fiber depends on
-    firstContextDependency: ContextDependency<any> | null;
-
-    // Bitfield that describes properties about the fiber and its subtree. E.g.
-    // the AsyncMode flag indicates whether the subtree should be async-by-
-    // default. When a fiber is created, it inherits the mode of its
-    // parent. Additional flags can be set at creation time, but after that the
-    // value should remain unchanged throughout the fiber's lifetime, particularly
-    // before its child fibers are created.
-    mode: TypeOfMode;
-
-    // Effect
-    effectTag: SideEffectTag;
-
-    // Singly linked list fast path to the next fiber with side-effects.
-    nextEffect: Fiber | null;
-
-    // The first and last fiber with side-effect within this subtree. This allows
-    // us to reuse a slice of the linked list when we reuse the work done within
-    // this fiber.
-    firstEffect: Fiber | null;
-    lastEffect: Fiber | null;
-
-    // Represents a time in the future by which this work should be completed.
-    // Does not include work found in its subtree.
-    expirationTime: ExpirationTime;
-
-    // This is used to quickly determine if a subtree has no pending changes.
-    childExpirationTime: ExpirationTime;
-
-    // This is a pooled version of a Fiber. Every fiber that gets updated will
-    // eventually have a pair. There are cases when we can clean up pairs to save
-    // memory if we need to.
-    alternate: Fiber | null;
-
-    // Time spent rendering this Fiber and its descendants for the current update.
-    // This tells us how well the tree makes use of sCU for memoization.
-    // It is reset to 0 each time we render and only updated when we don't bailout.
-    // This field is only set when the enableProfilerTimer flag is enabled.
-    actualDuration?: number;
-
-    // If the Fiber is currently active in the "render" phase,
-    // This marks the time at which the work began.
-    // This field is only set when the enableProfilerTimer flag is enabled.
-    actualStartTime?: number;
-
-    // Duration of the most recent render time for this Fiber.
-    // This value is not updated when we bailout for memoization purposes.
-    // This field is only set when the enableProfilerTimer flag is enabled.
-    selfBaseDuration?: number;
-
-    // Sum of base times for all descedents of this Fiber.
-    // This value bubbles up during the "complete" phase.
-    // This field is only set when the enableProfilerTimer flag is enabled.
-    treeBaseDuration?: number;
-
-    // Conceptual aliases
-    // workInProgress : Fiber ->  alternate The alternate used for reuse happens
-    // to be the same as work in progress.
-    // __DEV__ only
-    _debugID?: number;
-    _debugSource?: Source | null;
-    _debugOwner?: Fiber | null;
-    _debugIsCurrentlyTiming?: boolean;
-}
diff --git a/types/react-reconciler/ReactFiberExpirationTime.d.ts b/types/react-reconciler/ReactFiberExpirationTime.d.ts
deleted file mode 100644
index 8fb86f26ef..0000000000
--- a/types/react-reconciler/ReactFiberExpirationTime.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-export type ExpirationTime = number;
diff --git a/types/react-reconciler/ReactFiberNewContext.d.ts b/types/react-reconciler/ReactFiberNewContext.d.ts
deleted file mode 100644
index a212df9839..0000000000
--- a/types/react-reconciler/ReactFiberNewContext.d.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-import { ReactContext } from './ReactTypes';
-
-export interface ContextDependency<T> {
-    context: ReactContext<T>;
-    observedBits: number;
-    next: ContextDependency<any> | null;
-}
diff --git a/types/react-reconciler/ReactFiberReconciler.d.ts b/types/react-reconciler/ReactFiberReconciler.d.ts
deleted file mode 100644
index aa8ed61fe5..0000000000
--- a/types/react-reconciler/ReactFiberReconciler.d.ts
+++ /dev/null
@@ -1,255 +0,0 @@
-import { Component } from 'react';
-import { Fiber } from './ReactFiber';
-import { ExpirationTime } from './ReactFiberExpirationTime';
-import { FiberRoot } from './ReactFiberRoot';
-import { Deadline } from './ReactFiberScheduler';
-import { ReactNodeList } from './ReactTypes';
-
-export type OpaqueHandle = Fiber;
-export type OpaqueRoot = FiberRoot;
-
-export interface HostConfig<Type, Props, Container, Instance, TextInstance, HydratableInstance, PublicInstance, HostContext, UpdatePayload, ChildSet, TimeoutHandle, NoTimeout> {
-    getPublicInstance(instance: Instance | TextInstance): PublicInstance;
-    getRootHostContext(rootContainerInstance: Container): HostContext;
-    getChildHostContext(parentHostContext: HostContext, type: Type, rootContainerInstance: Container): HostContext;
-
-    prepareForCommit(containerInfo: Container): void;
-    resetAfterCommit(containerInfo: Container): void;
-
-    createInstance(
-        type: Type,
-        props: Props,
-        rootContainerInstance: Container,
-        hostContext: HostContext,
-        internalInstanceHandle: OpaqueHandle,
-    ): Instance;
-    appendInitialChild(parentInstance: Instance, child: Instance | TextInstance): void;
-    finalizeInitialChildren(
-        parentInstance: Instance,
-        type: Type,
-        props: Props,
-        rootContainerInstance: Container,
-        hostContext: HostContext,
-    ): boolean;
-
-    prepareUpdate(
-        instance: Instance,
-        type: Type,
-        oldProps: Props,
-        newProps: Props,
-        rootContainerInstance: Container,
-        hostContext: HostContext,
-    ): null | UpdatePayload;
-
-    shouldSetTextContent(type: Type, props: Props): boolean;
-    shouldDeprioritizeSubtree(type: Type, props: Props): boolean;
-
-    createTextInstance(
-        text: string,
-        rootContainerInstance: Container,
-        hostContext: HostContext,
-        internalInstanceHandle: OpaqueHandle,
-    ): TextInstance;
-
-    scheduleDeferredCallback(
-        callback: (deadline: Deadline) => void,
-        options?: { timeout: number },
-    ): any;
-    cancelDeferredCallback(callbackID: any): void;
-
-    setTimeout(handler: (...args: any[]) => void, timeout: number): TimeoutHandle | NoTimeout;
-    clearTimeout(handle: TimeoutHandle | NoTimeout): void;
-    noTimeout: NoTimeout;
-
-    now(): number;
-
-    // Temporary workaround for scenario where multiple renderers concurrently
-    // render using the same context objects. E.g. React DOM and React ART on the
-    // same page. DOM is the primary renderer; ART is the secondary renderer.
-    isPrimaryRenderer: boolean;
-
-    supportsMutation: boolean;
-    supportsPersistence: boolean;
-    supportsHydration: boolean;
-
-    // -------------------
-    //      Mutation
-    //     (optional)
-    // -------------------
-    appendChild?(parentInstance: Instance, child: Instance | TextInstance): void;
-    appendChildToContainer?(container: Container, child: Instance | TextInstance): void;
-    commitTextUpdate?(textInstance: TextInstance, oldText: string, newText: string): void;
-    commitMount?(
-        instance: Instance,
-        type: Type,
-        newProps: Props,
-        internalInstanceHandle: OpaqueHandle,
-    ): void;
-    commitUpdate?(
-        instance: Instance,
-        updatePayload: UpdatePayload,
-        type: Type,
-        oldProps: Props,
-        newProps: Props,
-        internalInstanceHandle: OpaqueHandle,
-    ): void;
-    insertBefore?(parentInstance: Instance, child: Instance | TextInstance, beforeChild: Instance | TextInstance): void;
-    insertInContainerBefore?(
-        container: Container,
-        child: Instance | TextInstance,
-        beforeChild: Instance | TextInstance,
-    ): void;
-    removeChild?(parentInstance: Instance, child: Instance | TextInstance): void;
-    removeChildFromContainer?(container: Container, child: Instance | TextInstance): void;
-    resetTextContent?(instance: Instance): void;
-
-    // -------------------
-    //     Persistence
-    //     (optional)
-    // -------------------
-    cloneInstance?(
-        instance: Instance,
-        updatePayload: null | UpdatePayload,
-        type: Type,
-        oldProps: Props,
-        newProps: Props,
-        internalInstanceHandle: OpaqueHandle,
-        keepChildren: boolean,
-        recyclableInstance: Instance,
-    ): Instance;
-
-    createContainerChildSet?(container: Container): ChildSet;
-
-    appendChildToContainerChildSet?(childSet: ChildSet, child: Instance | TextInstance): void;
-    finalizeContainerChildren?(container: Container, newChildren: ChildSet): void;
-
-    replaceContainerChildren?(container: Container, newChildren: ChildSet): void;
-
-    // -------------------
-    //     Hydration
-    //     (optional)
-    // -------------------
-    canHydrateInstance?(instance: HydratableInstance, type: Type, props: Props): null | Instance;
-    canHydrateTextInstance?(instance: HydratableInstance, text: string): null | TextInstance;
-    getNextHydratableSibling?(instance: Instance | TextInstance | HydratableInstance): null | HydratableInstance;
-    getFirstHydratableChild?(parentInstance: Instance | Container): null | HydratableInstance;
-    hydrateInstance?(
-        instance: Instance,
-        type: Type,
-        props: Props,
-        rootContainerInstance: Container,
-        hostContext: HostContext,
-        internalInstanceHandle: OpaqueHandle,
-    ): null | UpdatePayload;
-    hydrateTextInstance?(
-        textInstance: TextInstance,
-        text: string,
-        internalInstanceHandle: OpaqueHandle,
-    ): boolean;
-    didNotMatchHydratedContainerTextInstance?(
-        parentContainer: Container,
-        textInstance: TextInstance,
-        text: string,
-    ): void;
-    didNotMatchHydratedTextInstance?(
-        parentType: Type,
-        parentProps: Props,
-        parentInstance: Instance,
-        textInstance: TextInstance,
-        text: string,
-    ): void;
-    didNotHydrateContainerInstance?(parentContainer: Container, instance: Instance | TextInstance): void;
-    didNotHydrateInstance?(
-        parentType: Type,
-        parentProps: Props,
-        parentInstance: Instance,
-        instance: Instance | TextInstance,
-    ): void;
-    didNotFindHydratableContainerInstance?(
-        parentContainer: Container,
-        type: Type,
-        props: Props,
-    ): void;
-    didNotFindHydratableContainerTextInstance?(
-        parentContainer: Container,
-        text: string,
-    ): void;
-    didNotFindHydratableInstance?(
-        parentType: Type,
-        parentProps: Props,
-        parentInstance: Instance,
-        type: Type,
-        props: Props,
-    ): void;
-    didNotFindHydratableTextInstance?(
-        parentType: Type,
-        parentProps: Props,
-        parentInstance: Instance,
-        text: string,
-    ): void;
-}
-
-// 0 is PROD, 1 is DEV.
-// Might add PROFILE later.
-export type BundleType = 0 | 1;
-
-export interface DevToolsConfig<Instance, TextInstance> {
-    bundleType: BundleType;
-    version: string;
-    rendererPackageName: string;
-    // Note: this actually *does* depend on Fiber internal fields.
-    // Used by "inspect clicked DOM element" in React DevTools.
-    findFiberByHostInstance?: (instance: Instance | TextInstance) => Fiber;
-    // Used by RN in-app inspector.
-    // This API is unfortunately RN-specific.
-    // TODO: Change it to accept Fiber instead and type it properly.
-    getInspectorDataForViewTag?: (tag: number) => object;
-}
-
-export interface Reconciler<Instance, TextInstance, Container, PublicInstance> {
-    updateContainerAtExpirationTime(
-        element: ReactNodeList,
-        container: OpaqueRoot,
-        parentComponent: Component<any, any> | null | undefined,
-        expirationTime: ExpirationTime,
-        callback: () => void | null | undefined,
-    ): ExpirationTime;
-    createContainer(
-        containerInfo: Container,
-        isAsync: boolean,
-        hydrate: boolean,
-    ): OpaqueRoot;
-    updateContainer(
-        element: ReactNodeList,
-        container: OpaqueRoot,
-        parentComponent: Component<any, any> | null | undefined,
-        callback: () => void | null | undefined,
-    ): ExpirationTime;
-    flushRoot(root: OpaqueRoot, expirationTime: ExpirationTime): void;
-    requestWork(root: OpaqueRoot, expirationTime: ExpirationTime): void;
-    computeUniqueAsyncExpiration(): ExpirationTime;
-    batchedUpdates<A>(fn: () => A): A;
-    unbatchedUpdates<A>(fn: () => A): A;
-    deferredUpdates<A>(fn: () => A): A;
-    syncUpdates<A>(fn: () => A): A;
-    interactiveUpdates<A>(fn: () => A): A;
-    flushInteractiveUpdates(): void;
-    flushControlled(fn: () => any): void;
-    flushSync<A>(fn: () => A): A;
-
-    // Used to extract the return value from the initial render. Legacy API.
-    getPublicRootInstance(
-        container: OpaqueRoot,
-    ): Component<any, any> | PublicInstance | null;
-
-    // Use for findDOMNode/findHostNode. Legacy API.
-    findHostInstance(component: object): PublicInstance | null;
-
-    // Used internally for filtering out portals. Legacy API.
-    findHostInstanceWithNoPortals(component: Fiber): PublicInstance | null;
-    injectIntoDevTools(devToolsConfig: DevToolsConfig<Instance, TextInstance>): boolean;
-}
-
-export default function <Type, Props, Container, Instance, TextInstance, HydratableInstance, PublicInstance, HostContext, UpdatePayload, ChildSet, TimeoutHandle, NoTimeout>(
-    config: HostConfig<Type, Props, Container, Instance, TextInstance, HydratableInstance, PublicInstance, HostContext, UpdatePayload, ChildSet, TimeoutHandle, NoTimeout>,
-): Reconciler<Instance, TextInstance, Container, PublicInstance>;
diff --git a/types/react-reconciler/ReactFiberRoot.d.ts b/types/react-reconciler/ReactFiberRoot.d.ts
deleted file mode 100644
index 0117eb9d51..0000000000
--- a/types/react-reconciler/ReactFiberRoot.d.ts
+++ /dev/null
@@ -1,76 +0,0 @@
-import { Fiber } from './ReactFiber';
-import { ExpirationTime } from './ReactFiberExpirationTime';
-import { Interaction } from './Tracking';
-
-// TODO: This should be lifted into the renderer.
-export interface Batch {
-    _defer: boolean;
-    _expirationTime: ExpirationTime;
-    _onComplete: () => any;
-    _next: Batch | null;
-}
-
-export type PendingInteractionMap = Map<ExpirationTime, Set<Interaction>>;
-
-export interface BaseFiberRootProperties {
-    // Any additional information from the host associated with this root.
-    containerInfo: any;
-    // Used only by persistent updates.
-    pendingChildren: any;
-    // The currently active root fiber. This is the mutable root of the tree.
-    current: Fiber;
-
-    // The following priority levels are used to distinguish between 1)
-    // uncommitted work, 2) uncommitted work that is suspended, and 3) uncommitted
-    // work that may be unsuspended. We choose not to track each individual
-    // pending level, trading granularity for performance.
-    //
-    // The earliest and latest priority levels that are suspended from committing.
-    earliestSuspendedTime: ExpirationTime;
-    latestSuspendedTime: ExpirationTime;
-    // The earliest and latest priority levels that are not known to be suspended.
-    earliestPendingTime: ExpirationTime;
-    latestPendingTime: ExpirationTime;
-    // The latest priority level that was pinged by a resolved promise and can
-    // be retried.
-    latestPingedTime: ExpirationTime;
-
-    // If an error is thrown, and there are no more updates in the queue, we try
-    // rendering from the root one more time, synchronously, before handling
-    // the error.
-    didError: boolean;
-
-    pendingCommitExpirationTime: ExpirationTime;
-    // A finished work-in-progress HostRoot that's ready to be committed.
-    finishedWork: Fiber | null;
-    // Timeout handle returned by setTimeout. Used to cancel a pending timeout, if
-    // it's superseded by a new one.
-    timeoutHandle: any;
-    // Top context object, used by renderSubtreeIntoContainer
-    context: object | null;
-    pendingContext: object | null;
-    // Determines if we should attempt to hydrate on the initial mount
-    readonly hydrate: boolean;
-    // Remaining expiration time on this root.
-    // TODO: Lift this into the renderer
-    nextExpirationTimeToWorkOn: ExpirationTime;
-    expirationTime: ExpirationTime;
-    // List of top-level batches. This list indicates whether a commit should be
-    // deferred. Also contains completion callbacks.
-    // TODO: Lift this into the renderer
-    firstBatch: Batch | null;
-    // Linked-list of roots
-    nextScheduledRoot: FiberRoot | null;
-}
-
-// The following attributes are only used by interaction tracking builds.
-// They enable interactions to be associated with their async work,
-// And expose interaction metadata to the React DevTools Profiler plugin.
-// Note that these attributes are only defined when the enableSchedulerTracking flag is enabled.
-export interface ProfilingOnlyFiberRootProperties {
-    interactionThreadID: number;
-    memoizedInteractions: Set<Interaction>;
-    pendingInteractionMap: PendingInteractionMap;
-}
-
-export type FiberRoot = BaseFiberRootProperties & ProfilingOnlyFiberRootProperties;
diff --git a/types/react-reconciler/ReactFiberScheduler.d.ts b/types/react-reconciler/ReactFiberScheduler.d.ts
deleted file mode 100644
index cfbadb016d..0000000000
--- a/types/react-reconciler/ReactFiberScheduler.d.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-export interface Deadline {
-    timeRemaining: () => number;
-    didTimeout: boolean;
-}
diff --git a/types/react-reconciler/ReactSideEffectTags.d.ts b/types/react-reconciler/ReactSideEffectTags.d.ts
deleted file mode 100644
index e2eec15313..0000000000
--- a/types/react-reconciler/ReactSideEffectTags.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-export type SideEffectTag = number;
diff --git a/types/react-reconciler/ReactTypeOfMode.d.ts b/types/react-reconciler/ReactTypeOfMode.d.ts
deleted file mode 100644
index 3e5c56b922..0000000000
--- a/types/react-reconciler/ReactTypeOfMode.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-export type TypeOfMode = number;
diff --git a/types/react-reconciler/ReactTypes.d.ts b/types/react-reconciler/ReactTypes.d.ts
deleted file mode 100644
index d962385049..0000000000
--- a/types/react-reconciler/ReactTypes.d.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-import { ReactNode } from 'react';
-
-export type ReactEmpty = null | undefined | boolean;
-
-export type ReactNodeList = ReactEmpty | ReactNode;
-
-export interface ReactProviderType<T> {
-    $$typeof: symbol | number;
-    _context: ReactContext<T>;
-}
-
-export interface ReactContext<T> {
-    $$typeof: symbol | number;
-    Consumer: ReactContext<T>;
-    Provider: ReactProviderType<T>;
-    unstable_read: () => T;
-
-    _calculateChangedBits: ((a: T, b: T) => number) | null;
-
-    _currentValue: T;
-    _currentValue2: T;
-
-    // DEV only
-    _currentRenderer?: object | null;
-    _currentRenderer2?: object | null;
-}
-
-export interface RefObject {
-    current: any;
-}
diff --git a/types/react-reconciler/ReactUpdateQueue.d.ts b/types/react-reconciler/ReactUpdateQueue.d.ts
deleted file mode 100644
index 497ce9f0f6..0000000000
--- a/types/react-reconciler/ReactUpdateQueue.d.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-import { ExpirationTime } from './ReactFiberExpirationTime';
-
-export interface Update<State> {
-    expirationTime: ExpirationTime;
-
-    tag: 0 | 1 | 2 | 3;
-    payload: any;
-    callback: (() => any) | null;
-
-    next: Update<State> | null;
-    nextEffect: Update<State> | null;
-}
-
-export interface UpdateQueue<State> {
-    baseState: State;
-
-    firstUpdate: Update<State> | null;
-    lastUpdate: Update<State> | null;
-
-    firstCapturedUpdate: Update<State> | null;
-    lastCapturedUpdate: Update<State> | null;
-
-    firstEffect: Update<State> | null;
-    lastEffect: Update<State> | null;
-
-    firstCapturedEffect: Update<State> | null;
-    lastCapturedEffect: Update<State> | null;
-}
diff --git a/types/react-reconciler/ReactWorkTags.d.ts b/types/react-reconciler/ReactWorkTags.d.ts
deleted file mode 100644
index fe7d38193c..0000000000
--- a/types/react-reconciler/ReactWorkTags.d.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-export type WorkTag =
-    | 0
-    | 1
-    | 2
-    | 3
-    | 4
-    | 5
-    | 6
-    | 7
-    | 8
-    | 9
-    | 10
-    | 11
-    | 12
-    | 13
-    | 14
-    | 15
-    | 16;
diff --git a/types/react-reconciler/Tracking.d.ts b/types/react-reconciler/Tracking.d.ts
deleted file mode 100644
index 145815131c..0000000000
--- a/types/react-reconciler/Tracking.d.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-export interface Interaction {
-    __count: number;
-    id: number;
-    name: string;
-    timestamp: number;
-}
diff --git a/types/react-reconciler/index.d.ts b/types/react-reconciler/index.d.ts
index 97be10b84f..38f0cc92a3 100644
--- a/types/react-reconciler/index.d.ts
+++ b/types/react-reconciler/index.d.ts
@@ -4,17 +4,582 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 
-export { default } from './ReactFiberReconciler';
+import { Component, ReactNode } from 'react';
 
-export * from './ReactElementType';
-export * from './ReactFiber';
-export * from './ReactFiberNewContext';
-export * from './ReactFiberReconciler';
-export * from './ReactFiberRoot';
-export * from './ReactFiberScheduler';
-export * from './ReactSideEffectTags';
-export * from './ReactTypeOfMode';
-export * from './ReactTypes';
-export * from './ReactUpdateQueue';
-export * from './ReactWorkTags';
-export * from './Tracking';
+declare function ReactReconciler<Type, Props, Container, Instance, TextInstance, HydratableInstance, PublicInstance, HostContext, UpdatePayload, ChildSet, TimeoutHandle, NoTimeout>(
+    config: ReactReconciler.HostConfig<Type, Props, Container, Instance, TextInstance, HydratableInstance, PublicInstance, HostContext, UpdatePayload, ChildSet, TimeoutHandle, NoTimeout>,
+): ReactReconciler.Reconciler<Instance, TextInstance, Container, PublicInstance>;
+
+declare namespace ReactReconciler {
+    // react-ronciler/ReactFiber
+
+    // A Fiber is work on a Component that needs to be done or was done. There can
+    // be more than one per component.
+    interface Fiber {
+        // These first fields are conceptually members of an Instance. This used to
+        // be split into a separate type and intersected with the other Fiber fields,
+        // but until Flow fixes its intersection bugs, we've merged them into a
+        // single type.
+
+        // An Instance is shared between all versions of a component. We can easily
+        // break this out into a separate object to avoid copying so much to the
+        // alternate versions of the tree. We put this on a single object for now to
+        // minimize the number of objects created during the initial render.
+
+        // Tag identifying the type of fiber.
+        tag: WorkTag;
+
+        // Unique identifier of this child.
+        key: null | string;
+
+        // The function/class/module associated with this fiber.
+        type: any;
+
+        // The local state associated with this fiber.
+        stateNode: any;
+
+        // Conceptual aliases
+        // parent : Instance -> return The parent happens to be the same as the
+        // return fiber since we've merged the fiber and instance.
+
+        // Remaining fields belong to Fiber
+
+        // The Fiber to return to after finishing processing this one.
+        // This is effectively the parent, but there can be multiple parents (two)
+        // so this is only the parent of the thing we're currently processing.
+        // It is conceptually the same as the return address of a stack frame.
+        return: Fiber | null;
+
+        // Singly Linked List Tree Structure.
+        child: Fiber | null;
+        sibling: Fiber | null;
+        index: number;
+
+        // The ref last used to attach this node.
+        // I'll avoid adding an owner field for prod and model that as functions.
+        ref: null | (((handle: any) => void) & { _stringRef: string | null | undefined }) | RefObject;
+
+        // Input is the data coming into process this fiber. Arguments. Props.
+        pendingProps: any; // This type will be more specific once we overload the tag.
+        memoizedProps: any; // The props used to create the output.
+
+        // A queue of state updates and callbacks.
+        updateQueue: UpdateQueue<any> | null;
+
+        // The state used to create the output
+        memoizedState: any;
+
+        // A linked-list of contexts that this fiber depends on
+        firstContextDependency: ContextDependency<any> | null;
+
+        // Bitfield that describes properties about the fiber and its subtree. E.g.
+        // the AsyncMode flag indicates whether the subtree should be async-by-
+        // default. When a fiber is created, it inherits the mode of its
+        // parent. Additional flags can be set at creation time, but after that the
+        // value should remain unchanged throughout the fiber's lifetime, particularly
+        // before its child fibers are created.
+        mode: TypeOfMode;
+
+        // Effect
+        effectTag: SideEffectTag;
+
+        // Singly linked list fast path to the next fiber with side-effects.
+        nextEffect: Fiber | null;
+
+        // The first and last fiber with side-effect within this subtree. This allows
+        // us to reuse a slice of the linked list when we reuse the work done within
+        // this fiber.
+        firstEffect: Fiber | null;
+        lastEffect: Fiber | null;
+
+        // Represents a time in the future by which this work should be completed.
+        // Does not include work found in its subtree.
+        expirationTime: ExpirationTime;
+
+        // This is used to quickly determine if a subtree has no pending changes.
+        childExpirationTime: ExpirationTime;
+
+        // This is a pooled version of a Fiber. Every fiber that gets updated will
+        // eventually have a pair. There are cases when we can clean up pairs to save
+        // memory if we need to.
+        alternate: Fiber | null;
+
+        // Time spent rendering this Fiber and its descendants for the current update.
+        // This tells us how well the tree makes use of sCU for memoization.
+        // It is reset to 0 each time we render and only updated when we don't bailout.
+        // This field is only set when the enableProfilerTimer flag is enabled.
+        actualDuration?: number;
+
+        // If the Fiber is currently active in the "render" phase,
+        // This marks the time at which the work began.
+        // This field is only set when the enableProfilerTimer flag is enabled.
+        actualStartTime?: number;
+
+        // Duration of the most recent render time for this Fiber.
+        // This value is not updated when we bailout for memoization purposes.
+        // This field is only set when the enableProfilerTimer flag is enabled.
+        selfBaseDuration?: number;
+
+        // Sum of base times for all descedents of this Fiber.
+        // This value bubbles up during the "complete" phase.
+        // This field is only set when the enableProfilerTimer flag is enabled.
+        treeBaseDuration?: number;
+
+        // Conceptual aliases
+        // workInProgress : Fiber ->  alternate The alternate used for reuse happens
+        // to be the same as work in progress.
+        // __DEV__ only
+        _debugID?: number;
+        _debugSource?: Source | null;
+        _debugOwner?: Fiber | null;
+        _debugIsCurrentlyTiming?: boolean;
+    }
+
+    // react-reconciler/ReactFiberExpirationTime
+
+    type ExpirationTime = number;
+
+    // react-reconciler/ReactFiberNewContext
+
+    interface ContextDependency<T> {
+        context: ReactContext<T>;
+        observedBits: number;
+        next: ContextDependency<any> | null;
+    }
+
+    // react-reconciler/ReactFiberReconciler
+
+    type OpaqueHandle = Fiber;
+    type OpaqueRoot = FiberRoot;
+
+    interface HostConfig<Type, Props, Container, Instance, TextInstance, HydratableInstance, PublicInstance, HostContext, UpdatePayload, ChildSet, TimeoutHandle, NoTimeout> {
+        getPublicInstance(instance: Instance | TextInstance): PublicInstance;
+        getRootHostContext(rootContainerInstance: Container): HostContext;
+        getChildHostContext(parentHostContext: HostContext, type: Type, rootContainerInstance: Container): HostContext;
+
+        prepareForCommit(containerInfo: Container): void;
+        resetAfterCommit(containerInfo: Container): void;
+
+        createInstance(
+            type: Type,
+            props: Props,
+            rootContainerInstance: Container,
+            hostContext: HostContext,
+            internalInstanceHandle: OpaqueHandle,
+        ): Instance;
+        appendInitialChild(parentInstance: Instance, child: Instance | TextInstance): void;
+        finalizeInitialChildren(
+            parentInstance: Instance,
+            type: Type,
+            props: Props,
+            rootContainerInstance: Container,
+            hostContext: HostContext,
+        ): boolean;
+
+        prepareUpdate(
+            instance: Instance,
+            type: Type,
+            oldProps: Props,
+            newProps: Props,
+            rootContainerInstance: Container,
+            hostContext: HostContext,
+        ): null | UpdatePayload;
+
+        shouldSetTextContent(type: Type, props: Props): boolean;
+        shouldDeprioritizeSubtree(type: Type, props: Props): boolean;
+
+        createTextInstance(
+            text: string,
+            rootContainerInstance: Container,
+            hostContext: HostContext,
+            internalInstanceHandle: OpaqueHandle,
+        ): TextInstance;
+
+        scheduleDeferredCallback(
+            callback: (deadline: Deadline) => void,
+            options?: { timeout: number },
+        ): any;
+        cancelDeferredCallback(callbackID: any): void;
+
+        setTimeout(handler: (...args: any[]) => void, timeout: number): TimeoutHandle | NoTimeout;
+        clearTimeout(handle: TimeoutHandle | NoTimeout): void;
+        noTimeout: NoTimeout;
+
+        now(): number;
+
+        // Temporary workaround for scenario where multiple renderers concurrently
+        // render using the same context objects. E.g. React DOM and React ART on the
+        // same page. DOM is the primary renderer; ART is the secondary renderer.
+        isPrimaryRenderer: boolean;
+
+        supportsMutation: boolean;
+        supportsPersistence: boolean;
+        supportsHydration: boolean;
+
+        // -------------------
+        //      Mutation
+        //     (optional)
+        // -------------------
+        appendChild?(parentInstance: Instance, child: Instance | TextInstance): void;
+        appendChildToContainer?(container: Container, child: Instance | TextInstance): void;
+        commitTextUpdate?(textInstance: TextInstance, oldText: string, newText: string): void;
+        commitMount?(
+            instance: Instance,
+            type: Type,
+            newProps: Props,
+            internalInstanceHandle: OpaqueHandle,
+        ): void;
+        commitUpdate?(
+            instance: Instance,
+            updatePayload: UpdatePayload,
+            type: Type,
+            oldProps: Props,
+            newProps: Props,
+            internalInstanceHandle: OpaqueHandle,
+        ): void;
+        insertBefore?(parentInstance: Instance, child: Instance | TextInstance, beforeChild: Instance | TextInstance): void;
+        insertInContainerBefore?(
+            container: Container,
+            child: Instance | TextInstance,
+            beforeChild: Instance | TextInstance,
+        ): void;
+        removeChild?(parentInstance: Instance, child: Instance | TextInstance): void;
+        removeChildFromContainer?(container: Container, child: Instance | TextInstance): void;
+        resetTextContent?(instance: Instance): void;
+
+        // -------------------
+        //     Persistence
+        //     (optional)
+        // -------------------
+        cloneInstance?(
+            instance: Instance,
+            updatePayload: null | UpdatePayload,
+            type: Type,
+            oldProps: Props,
+            newProps: Props,
+            internalInstanceHandle: OpaqueHandle,
+            keepChildren: boolean,
+            recyclableInstance: Instance,
+        ): Instance;
+
+        createContainerChildSet?(container: Container): ChildSet;
+
+        appendChildToContainerChildSet?(childSet: ChildSet, child: Instance | TextInstance): void;
+        finalizeContainerChildren?(container: Container, newChildren: ChildSet): void;
+
+        replaceContainerChildren?(container: Container, newChildren: ChildSet): void;
+
+        // -------------------
+        //     Hydration
+        //     (optional)
+        // -------------------
+        canHydrateInstance?(instance: HydratableInstance, type: Type, props: Props): null | Instance;
+        canHydrateTextInstance?(instance: HydratableInstance, text: string): null | TextInstance;
+        getNextHydratableSibling?(instance: Instance | TextInstance | HydratableInstance): null | HydratableInstance;
+        getFirstHydratableChild?(parentInstance: Instance | Container): null | HydratableInstance;
+        hydrateInstance?(
+            instance: Instance,
+            type: Type,
+            props: Props,
+            rootContainerInstance: Container,
+            hostContext: HostContext,
+            internalInstanceHandle: OpaqueHandle,
+        ): null | UpdatePayload;
+        hydrateTextInstance?(
+            textInstance: TextInstance,
+            text: string,
+            internalInstanceHandle: OpaqueHandle,
+        ): boolean;
+        didNotMatchHydratedContainerTextInstance?(
+            parentContainer: Container,
+            textInstance: TextInstance,
+            text: string,
+        ): void;
+        didNotMatchHydratedTextInstance?(
+            parentType: Type,
+            parentProps: Props,
+            parentInstance: Instance,
+            textInstance: TextInstance,
+            text: string,
+        ): void;
+        didNotHydrateContainerInstance?(parentContainer: Container, instance: Instance | TextInstance): void;
+        didNotHydrateInstance?(
+            parentType: Type,
+            parentProps: Props,
+            parentInstance: Instance,
+            instance: Instance | TextInstance,
+        ): void;
+        didNotFindHydratableContainerInstance?(
+            parentContainer: Container,
+            type: Type,
+            props: Props,
+        ): void;
+        didNotFindHydratableContainerTextInstance?(
+            parentContainer: Container,
+            text: string,
+        ): void;
+        didNotFindHydratableInstance?(
+            parentType: Type,
+            parentProps: Props,
+            parentInstance: Instance,
+            type: Type,
+            props: Props,
+        ): void;
+        didNotFindHydratableTextInstance?(
+            parentType: Type,
+            parentProps: Props,
+            parentInstance: Instance,
+            text: string,
+        ): void;
+    }
+
+    // 0 is PROD, 1 is DEV.
+    // Might add PROFILE later.
+    type BundleType = 0 | 1;
+
+    interface DevToolsConfig<Instance, TextInstance> {
+        bundleType: BundleType;
+        version: string;
+        rendererPackageName: string;
+        // Note: this actually *does* depend on Fiber internal fields.
+        // Used by "inspect clicked DOM element" in React DevTools.
+        findFiberByHostInstance?: (instance: Instance | TextInstance) => Fiber;
+        // Used by RN in-app inspector.
+        // This API is unfortunately RN-specific.
+        // TODO: Change it to accept Fiber instead and type it properly.
+        getInspectorDataForViewTag?: (tag: number) => object;
+    }
+
+    interface Reconciler<Instance, TextInstance, Container, PublicInstance> {
+        updateContainerAtExpirationTime(
+            element: ReactNodeList,
+            container: OpaqueRoot,
+            parentComponent: Component<any, any> | null | undefined,
+            expirationTime: ExpirationTime,
+            callback: () => void | null | undefined,
+        ): ExpirationTime;
+        createContainer(
+            containerInfo: Container,
+            isAsync: boolean,
+            hydrate: boolean,
+        ): OpaqueRoot;
+        updateContainer(
+            element: ReactNodeList,
+            container: OpaqueRoot,
+            parentComponent: Component<any, any> | null | undefined,
+            callback: () => void | null | undefined,
+        ): ExpirationTime;
+        flushRoot(root: OpaqueRoot, expirationTime: ExpirationTime): void;
+        requestWork(root: OpaqueRoot, expirationTime: ExpirationTime): void;
+        computeUniqueAsyncExpiration(): ExpirationTime;
+        batchedUpdates<A>(fn: () => A): A;
+        unbatchedUpdates<A>(fn: () => A): A;
+        deferredUpdates<A>(fn: () => A): A;
+        syncUpdates<A>(fn: () => A): A;
+        interactiveUpdates<A>(fn: () => A): A;
+        flushInteractiveUpdates(): void;
+        flushControlled(fn: () => any): void;
+        flushSync<A>(fn: () => A): A;
+
+        // Used to extract the return value from the initial render. Legacy API.
+        getPublicRootInstance(
+            container: OpaqueRoot,
+        ): Component<any, any> | PublicInstance | null;
+
+        // Use for findDOMNode/findHostNode. Legacy API.
+        findHostInstance(component: object): PublicInstance | null;
+
+        // Used internally for filtering out portals. Legacy API.
+        findHostInstanceWithNoPortals(component: Fiber): PublicInstance | null;
+        injectIntoDevTools(devToolsConfig: DevToolsConfig<Instance, TextInstance>): boolean;
+    }
+
+    // react-reconciler/ReactFiberRoot
+
+    // TODO: This should be lifted into the renderer.
+    interface Batch {
+        _defer: boolean;
+        _expirationTime: ExpirationTime;
+        _onComplete: () => any;
+        _next: Batch | null;
+    }
+
+    type PendingInteractionMap = Map<ExpirationTime, Set<Interaction>>;
+
+    interface BaseFiberRootProperties {
+        // Any additional information from the host associated with this root.
+        containerInfo: any;
+        // Used only by persistent updates.
+        pendingChildren: any;
+        // The currently active root fiber. This is the mutable root of the tree.
+        current: Fiber;
+
+        // The following priority levels are used to distinguish between 1)
+        // uncommitted work, 2) uncommitted work that is suspended, and 3) uncommitted
+        // work that may be unsuspended. We choose not to track each individual
+        // pending level, trading granularity for performance.
+        //
+        // The earliest and latest priority levels that are suspended from committing.
+        earliestSuspendedTime: ExpirationTime;
+        latestSuspendedTime: ExpirationTime;
+        // The earliest and latest priority levels that are not known to be suspended.
+        earliestPendingTime: ExpirationTime;
+        latestPendingTime: ExpirationTime;
+        // The latest priority level that was pinged by a resolved promise and can
+        // be retried.
+        latestPingedTime: ExpirationTime;
+
+        // If an error is thrown, and there are no more updates in the queue, we try
+        // rendering from the root one more time, synchronously, before handling
+        // the error.
+        didError: boolean;
+
+        pendingCommitExpirationTime: ExpirationTime;
+        // A finished work-in-progress HostRoot that's ready to be committed.
+        finishedWork: Fiber | null;
+        // Timeout handle returned by setTimeout. Used to cancel a pending timeout, if
+        // it's superseded by a new one.
+        timeoutHandle: any;
+        // Top context object, used by renderSubtreeIntoContainer
+        context: object | null;
+        pendingContext: object | null;
+        // Determines if we should attempt to hydrate on the initial mount
+        readonly hydrate: boolean;
+        // Remaining expiration time on this root.
+        // TODO: Lift this into the renderer
+        nextExpirationTimeToWorkOn: ExpirationTime;
+        expirationTime: ExpirationTime;
+        // List of top-level batches. This list indicates whether a commit should be
+        // deferred. Also contains completion callbacks.
+        // TODO: Lift this into the renderer
+        firstBatch: Batch | null;
+        // Linked-list of roots
+        nextScheduledRoot: FiberRoot | null;
+    }
+
+    // The following attributes are only used by interaction tracking builds.
+    // They enable interactions to be associated with their async work,
+    // And expose interaction metadata to the React DevTools Profiler plugin.
+    // Note that these attributes are only defined when the enableSchedulerTracking flag is enabled.
+    interface ProfilingOnlyFiberRootProperties {
+        interactionThreadID: number;
+        memoizedInteractions: Set<Interaction>;
+        pendingInteractionMap: PendingInteractionMap;
+    }
+
+    type FiberRoot = BaseFiberRootProperties & ProfilingOnlyFiberRootProperties;
+
+    // react-reconciler/ReactFiberScheduler
+
+    interface Deadline {
+        timeRemaining: () => number;
+        didTimeout: boolean;
+    }
+
+    // react-reconciler/ReactTypeOfMode
+
+    type TypeOfMode = number;
+
+    // react-reconciler/ReactUpdateQueue
+
+    interface Update<State> {
+        expirationTime: ExpirationTime;
+
+        tag: 0 | 1 | 2 | 3;
+        payload: any;
+        callback: (() => any) | null;
+
+        next: Update<State> | null;
+        nextEffect: Update<State> | null;
+    }
+
+    interface UpdateQueue<State> {
+        baseState: State;
+
+        firstUpdate: Update<State> | null;
+        lastUpdate: Update<State> | null;
+
+        firstCapturedUpdate: Update<State> | null;
+        lastCapturedUpdate: Update<State> | null;
+
+        firstEffect: Update<State> | null;
+        lastEffect: Update<State> | null;
+
+        firstCapturedEffect: Update<State> | null;
+        lastCapturedEffect: Update<State> | null;
+    }
+
+    // schedule/Tracking
+
+    interface Interaction {
+        __count: number;
+        id: number;
+        name: string;
+        timestamp: number;
+    }
+
+    // shared/ReactElementType
+
+    interface Source {
+        fileName: string;
+        lineNumber: number;
+    }
+
+    // shared/ReactSideEffectTags
+
+    type SideEffectTag = number;
+
+    // shared/ReactTypes
+
+    type ReactEmpty = null | undefined | boolean;
+
+    type ReactNodeList = ReactEmpty | ReactNode;
+
+    interface ReactProviderType<T> {
+        $$typeof: symbol | number;
+        _context: ReactContext<T>;
+    }
+
+    interface ReactContext<T> {
+        $$typeof: symbol | number;
+        Consumer: ReactContext<T>;
+        Provider: ReactProviderType<T>;
+        unstable_read: () => T;
+
+        _calculateChangedBits: ((a: T, b: T) => number) | null;
+
+        _currentValue: T;
+        _currentValue2: T;
+
+        // DEV only
+        _currentRenderer?: object | null;
+        _currentRenderer2?: object | null;
+    }
+
+    interface RefObject {
+        current: any;
+    }
+
+    // shared/ReactWorkTags
+
+    type WorkTag =
+        | 0
+        | 1
+        | 2
+        | 3
+        | 4
+        | 5
+        | 6
+        | 7
+        | 8
+        | 9
+        | 10
+        | 11
+        | 12
+        | 13
+        | 14
+        | 15
+        | 16;
+}
+
+export = ReactReconciler;
diff --git a/types/react-reconciler/test/react-reconciler-tests.ts b/types/react-reconciler/test/react-reconciler-tests.ts
index 9008446d6a..5896ff1ea3 100644
--- a/types/react-reconciler/test/react-reconciler-tests.ts
+++ b/types/react-reconciler/test/react-reconciler-tests.ts
@@ -1,4 +1,4 @@
-import ReactFiberReconciler from 'react-reconciler';
+import * as ReactFiberReconciler from 'react-reconciler';
 import * as ReactTestHostConfig from './ReactTestHostConfig';
 
 // $ExpectType Reconciler<Instance, TextInstance, Container, HydratableInstance>