diff --git a/packages/grpc-native-core/index.d.ts b/packages/grpc-native-core/index.d.ts
new file mode 100644
index 00000000..12e9bd5a
--- /dev/null
+++ b/packages/grpc-native-core/index.d.ts
@@ -0,0 +1,1214 @@
+declare module "grpc" {
+  import { Service } from "protobufjs";
+
+  /**
+   * Load a ProtoBuf.js object as a gRPC object.
+   * @param value The ProtoBuf.js reflection object to load
+   * @param options Options to apply to the loaded file
+   * @return The resulting gRPC object.
+   */
+  export function loadObject(value: object, options?: LoadObjectOptions): GrpcObject;
+
+  /**
+   * Options for loading proto object as gRPC object
+   * @param {(number|string)=} [options.protobufjsVersion='detect'] 5 and 6
+   *     respectively indicate that an object from the corresponding version of
+   *     Protobuf.js is provided in the value argument. If the option is 'detect',
+   *     gRPC will guess what the version is based on the structure of the value.
+   */
+  export interface LoadObjectOptions {
+    /**
+     * Deserialize bytes values as base64 strings instead of Buffers.
+     * Defaults to `false`.
+     */
+    binaryAsBase64?: boolean;
+
+    /**
+     * Deserialize long values as strings instead of objects.
+     * Defaults to `true`.
+     */
+    longsAsStrings?: boolean;
+
+    /**
+     * Deserialize enum values as strings instead of numbers. Only works with
+     * Protobuf.js 6 values.
+     * Defaults to `true`.
+     */
+    enumsAsStrings?: boolean;
+
+    /**
+     * use the beta method argument order for client methods, with optional
+     * arguments after the callback. This option is only a temporary stopgap
+     * measure to smooth an API breakage. It is deprecated, and new code
+     * should not use it.
+     * Defaults to `false`
+     */
+    deprecatedArgumentOrder?: boolean;
+
+    /**
+     * 5 and 6 respectively indicate that an object from the corresponding
+     * version of Protobuf.js is provided in the value argument. If the option
+     * is 'detect', gRPC wll guess what the version is based on the structure
+     * of the value.
+     */
+    protobufjsVersion?: 5 | 6 | "detect";
+  }
+
+  /**
+   * Map from `.proto` file.
+   * - Namespaces become maps from the names of their direct members to those member objects
+   * - Service definitions become client constructors for clients for that service. They also
+   *   have a service member that can be used for constructing servers.
+   * - Message definitions become Message constructors like those that ProtoBuf.js would create
+   * - Enum definitions become Enum objects like those that ProtoBuf.js would create
+   * - Anything else becomes the relevant reflection object that ProtoBuf.js would create
+   */
+  export interface GrpcObject {
+    [namespace: string]: {
+      [service: string]: typeof Client,
+    };
+  }
+
+  /**
+   * Load a gRPC object from a .proto file.
+   * @param filename The file to load
+   * @param format The file format to expect. Defaults to 'proto'
+   * @param options Options to apply to the loaded file
+   * @return The resulting gRPC object
+   */
+  export function load(filename: Filename, format?: "proto" | "json", options?: LoadOptions): GrpcObject;
+
+  /**
+   * A filename
+   */
+  export type Filename = string | { root: string, file: string };
+
+  /**
+   * Options for loading proto file as gRPC object
+   */
+  export interface LoadOptions {
+    /**
+     * Load this file with field names in camel case instead of their original case.
+     * Defaults to `false`.
+     */
+    convertFieldsToCamelCase?: boolean;
+
+    /**
+     * Deserialize bytes values as base64 strings instead of Buffers.
+     * Defaults to `false`.
+     */
+    binaryAsBase64?: boolean;
+
+    /**
+     * Deserialize long values as strings instead of objects.
+     * Defaults to `true`.
+     */
+    longsAsStrings?: boolean;
+
+    /**
+     * Use the beta method argument order for client methods, with optional
+     * arguments after the callback. This option is only a temporary stopgap
+     * measure to smooth an API breakage. It is deprecated, and new code
+     * should not use it.
+     * Defaults to `false`
+     */
+    deprecatedArgumentOrder?: boolean;
+  }
+
+  /**
+   * Sets the logger function for the gRPC module. For debugging purposes, the C
+   * core will log synchronously directly to stdout unless this function is
+   * called. Note: the output format here is intended to be informational, and
+   * is not guaranteed to stay the same in the future.
+   * Logs will be directed to logger.error.
+   * @param logger A Console-like object.
+   */
+  export function setLogger(logger: Console): void;
+
+  /**
+   * Sets the logger verbosity for gRPC module logging. The options are members
+   * of the grpc.logVerbosity map.
+   * @param verbosity The minimum severity to log
+   */
+  export function setLogVerbosity(verbosity: number): void;
+
+  /**
+   * Server object that stores request handlers and delegates incoming requests to those handlers
+   */
+  export class Server {
+    /**
+     * Constructs a server object that stores request handlers and delegates
+     * incoming requests to those handlers
+     * @param options Options that should be passed to the internal server
+     *     implementation
+     * ```
+     * var server = new grpc.Server();
+     * server.addProtoService(protobuf_service_descriptor, service_implementation);
+     * server.bind('address:port', server_credential);
+     * server.start();
+     * ```
+     */
+    constructor(options?: object);
+
+    /**
+     * Start the server and begin handling requests
+     */
+    start(): void;
+
+    /**
+     * Registers a handler to handle the named method. Fails if there already is
+     * a handler for the given method. Returns true on success
+     * @param name The name of the method that the provided function should
+     *     handle/respond to.
+     * @param handler Function that takes a stream of
+     *     request values and returns a stream of response values
+     * @param serialize Serialization function for responses
+     * @param deserialize Deserialization function for requests
+     * @param type The streaming type of method that this handles
+     * @return True if the handler was set. False if a handler was already
+     *     set for that name.
+     */
+    register(name: string, handler: handleCall, serialize: serialize, deserialize: deserialize, type: string): boolean;
+
+    /**
+     * Gracefully shuts down the server. The server will stop receiving new calls,
+     * and any pending calls will complete. The callback will be called when all
+     * pending calls have completed and the server is fully shut down. This method
+     * is idempotent with itself and forceShutdown.
+     * @param {function()} callback The shutdown complete callback
+     */
+    tryShutdown(callback: () => void): void;
+
+    /**
+     * Forcibly shuts down the server. The server will stop receiving new calls
+     * and cancel all pending calls. When it returns, the server has shut down.
+     * This method is idempotent with itself and tryShutdown, and it will trigger
+     * any outstanding tryShutdown callbacks.
+     */
+    forceShutdown(): void;
+
+    /**
+     * Add a service to the server, with a corresponding implementation.
+     * @param service The service descriptor
+     * @param implementation Map of method names to method implementation
+     * for the provided service.
+     */
+    addService(service: Service, implementation: { [name: string]: handleCall }): void;
+
+    /**
+     * Add a proto service to the server, with a corresponding implementation
+     * @deprecated Use `Server#addService` instead
+     * @param service The proto service descriptor
+     * @param implementation Map of method names to method implementation
+     * for the provided service.
+     */
+    addProtoService(service: Service, implementation: { [name: string]: handleCall }): void;
+
+    /**
+     * Binds the server to the given port, with SSL disabled if creds is an
+     * insecure credentials object
+     * @param port The port that the server should bind on, in the format
+     * "address:port"
+     * @param creds Server credential object to be used for SSL. Pass an
+     * insecure credentials object for an insecure port.
+     */
+    bind(port: string, creds: ServerCredentials): void;
+  }
+
+  /**
+   * An object that completely defines a service.
+   * @typedef {Object.<string, grpc~MethodDefinition>} grpc~ServiceDefinition
+   */
+  export interface ServiceDefinition {
+    [s: string]: MethodDefinition;
+  }
+
+  /**
+   * An object that completely defines a service method signature.
+   */
+  export interface MethodDefinition {
+    /**
+     * The method's URL path
+     */
+    path: string;
+    /**
+     * Indicates whether the method accepts a stream of requests
+     */
+    requestStream: boolean;
+    /**
+     *  Indicates whether the method returns a stream of responses
+     */
+   responseStream: boolean;
+   /**
+    * Serialization function for request values
+    */
+    requestSerialize: serialize;
+    /**
+     * Serialization function for response values
+     */
+    responseSerialize: serialize;
+    /**
+     * Deserialization function for request data
+     */
+    requestDeserialize: deserialize;
+    /**
+     * Deserialization function for repsonse data
+     */
+    responseDeserialize: deserialize;
+  }
+
+  type handleCall = handleUnaryCall | handleClientStreamingCall | handleServerStreamingCall | handleBidiStreamingCall;
+
+  /**
+   * User-provided method to handle unary requests on a server
+   */
+  type handleUnaryCall = (call: ServerUnaryCall, callback: sendUnaryData) => void;
+
+  export class ServerUnaryCall {
+    /**
+     * Indicates if the call has been cancelled
+     */
+    cancelled: boolean;
+
+    /**
+     * The request metadata from the client
+     */
+    metadata: Metadata;
+
+    /**
+     * The request message from the client
+     */
+    request: any;
+
+    /**
+     * An EventEmitter. Used for unary calls.
+     * @param call The call object associated with the request
+     * @param metadata The request metadata from the client
+     */
+    constructor(call: Call, metadata: Metadata);
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+
+    /**
+     * Send the initial metadata for a writable stream.
+     * @param responseMetadata Metadata to send
+     */
+    sendMetadata(responseMetadata: Metadata): void;
+  }
+
+  /**
+   * User provided method to handle client streaming methods on the server.
+   */
+  type handleClientStreamingCall = (call: ServerReadableStream, callback: sendUnaryData) => void;
+
+  export class ServerReadableStream {
+    /**
+     * Indicates if the call has been cancelled
+     */
+    cancelled: boolean;
+
+    /**
+     * The request metadata from the client
+     */
+    metadata: Metadata;
+
+    /**
+     * A stream that the server can read from. Used for calls that are streaming
+     * from the client side.
+     * @param call The call object to read data with
+     * @param metadata The request metadata from the client
+     * @param deserialize Deserialization function for reads
+     */
+    constructor(call: Call, metadata: Metadata, deserialize: deserialize);
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+
+    /**
+     * Send the initial metadata for a writable stream.
+     * @param responseMetadata Metadata to send
+     */
+    sendMetadata(responseMetadata: Metadata): void;
+  }
+
+  /**
+   * User provided method to handle server streaming methods on the server.
+   */
+  type handleServerStreamingCall = (call: ServerWriteableStream) => void;
+
+  export class ServerWriteableStream {
+    /**
+     * Indicates if the call has been cancelled
+     */
+    cancelled: boolean;
+
+    /**
+     * The request metadata from the client
+     */
+    metadata: Metadata;
+
+    /**
+     * The request message from the client
+     */
+    request: any;
+
+    /**
+     * A stream that the server can write to. Used for calls that are streaming
+     * from the server side.
+     * @param call The call object to send data with
+     * @param metadata The request metadata from the client
+     * @param serialize Serialization function for writes
+     */
+    constructor(call: Call, metadata: Metadata, serialize: serialize);
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+
+    /**
+     * Send the initial metadata for a writable stream.
+     * @param responseMetadata Metadata to send
+     */
+    sendMetadata(responseMetadata: Metadata): void;
+  }
+
+  /**
+   * User provided method to handle bidirectional streaming calls on the server.
+   */
+  type handleBidiStreamingCall = (call: ServerDuplexStream) => void;
+
+  export class ServerDuplexStream {
+    /**
+     * A stream that the server can read from or write to. Used for calls
+     * with duplex streaming.
+     * @param call Call object to proxy
+     * @param metadata The request metadata from the client
+     * @param serialize Serialization function for requests
+     * @param deserialize Deserialization function for requests
+     */
+    constructor(call: any, metadata: Metadata, serialize: serialize, deserialize: deserialize);
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+
+    /**
+     * Send the initial metadata for a writable stream.
+     * @param responseMetadata Metadata to send
+     */
+    sendMetadata(responseMetadata: Metadata): void;
+  }
+
+  /**
+   * A deserialization function
+   * @param data The byte sequence to deserialize
+   * @return The data deserialized as a value
+   */
+  type deserialize = (data: Buffer) => any;
+
+  /**
+   * A serialization function
+   * @param value The value to serialize
+   * @return The value serialized as a byte sequence
+   */
+  type serialize = (value: any) => Buffer;
+
+  /**
+   * Callback function passed to server handlers that handle methods with
+   * unary responses.
+   */
+  type sendUnaryData = (error: ServiceError | null, value: any, trailer?: Metadata, flags?: number) => void;
+
+  export class Metadata {
+    /**
+     * Class for storing metadata. Keys are normalized to lowercase ASCII.
+     * ```
+     * var metadata = new metadata_module.Metadata();
+     * metadata.set('key1', 'value1');
+     * metadata.add('key1', 'value2');
+     * metadata.get('key1') // returns ['value1', 'value2']
+     * ```
+     */
+    constructor();
+
+    /**
+     * Sets the given value for the given key, replacing any other values associated
+     * with that key. Normalizes the key.
+     * @param key The key to set
+     * @param value The value to set. Must be a buffer if and only
+     *     if the normalized key ends with '-bin'
+     */
+    set(key: string, value: string | Buffer): void;
+
+    /**
+     * Adds the given value for the given key. Normalizes the key.
+     * @param key The key to add to.
+     * @param value The value to add. Must be a buffer if and only
+     *     if the normalized key ends with '-bin'
+     */
+    add(key: string, value: string | Buffer): void;
+
+    /**
+     * Remove the given key and any associated values. Normalizes the key.
+     * @param key The key to remove
+     */
+    remove(key: string): void;
+
+    /**
+     * Gets a list of all values associated with the key. Normalizes the key.
+     * @param key The key to get
+     * @return The values associated with that key
+     */
+    get(key: string): Array<string | Buffer>;
+
+    /**
+     * Get a map of each key to a single associated value. This reflects the most
+     * common way that people will want to see metadata.
+     * @return A key/value mapping of the metadata
+     */
+    getMap(): { [index: string]: string | Buffer };
+
+    /**
+     * Clone the metadata object.
+     * @return {Metadata} The new cloned object
+     */
+    clone(): Metadata;
+  }
+
+  /**
+   * Represents the status of a completed request. If `code` is
+   * `grpc.status.OK`, then the request has completed successfully.
+   * Otherwise, the request has failed, `details` will contain a description of
+   * the error. Either way, `metadata` contains the trailing response metadata
+   * sent by the server when it finishes processing the call.
+   */
+  export interface StatusObject {
+    /**
+     * The error code, a key of `grpc.status`
+     */
+    code: number;
+    /**
+     * Human-readable description of the status
+     */
+    details: string;
+    /**
+     * Trailing metadata sent with the status, if applicable
+     */
+    metadata: Metadata;
+  }
+
+  /**
+   * Describes how a request has failed. The member `message` will be the same as
+   * `details` in `StatusObject`, and `code` and `metadata` are the
+   * same as in that object.
+   */
+  export class ServiceError extends Error {
+    /**
+     * The error code, a key of {@link grpc.status} that is not `grpc.status.OK`
+     */
+    code: number;
+    /**
+     * Trailing metadata sent with the status, if applicable
+     */
+    metadata: Metadata;
+  }
+
+  /**
+   * ServerCredentials factories
+   */
+  export class ServerCredentials {
+    /**
+     * Create insecure server credentials
+     * @return The ServerCredentials
+     */
+    static createInsecure(): ServerCredentials;
+    /**
+     * Create SSL server credentials
+     * @param rootCerts Root CA certificates for validating client certificates
+     * @param keyCertPairs A list of private key and certificate chain pairs to
+     * be used for authenticating the server
+     * @param checkClientCertificate Indicates that the server should request
+     * and verify the client's certificates.
+     * Defaults to `false`.
+     * @return The ServerCredentials
+     */
+    static createInsecure(rootCerts: Buffer | null, keyCertPairs: KeyCertPair[], checkClientCertificate?: boolean): ServerCredentials;
+  }
+
+  /**
+   * A private key and certificate pair
+   */
+  export interface KeyCertPair {
+    /**
+     * The server's private key
+     */
+    privateKey: Buffer;
+
+    /**
+     * The server's certificate chain
+     */
+    certChain: Buffer;
+  }
+
+  /**
+   * Enum of status codes that gRPC can return
+   */
+  export enum status {
+    /**
+     * Not an error; returned on success
+     */
+    OK = 0,
+    /**
+     * The operation was cancelled (typically by the caller).
+     */
+    CANCELLED = 1,
+    /**
+     * Unknown error.  An example of where this error may be returned is
+     * if a status value received from another address space belongs to
+     * an error-space that is not known in this address space.  Also
+     * errors raised by APIs that do not return enough error information
+     * may be converted to this error.
+     */
+    UNKNOWN = 2,
+    /**
+     * Client specified an invalid argument.  Note that this differs
+     * from FAILED_PRECONDITION.  INVALID_ARGUMENT indicates arguments
+     * that are problematic regardless of the state of the system
+     * (e.g., a malformed file name).
+     */
+    INVALID_ARGUMENT = 3,
+    /**
+     * Deadline expired before operation could complete.  For operations
+     * that change the state of the system, this error may be returned
+     * even if the operation has completed successfully.  For example, a
+     * successful response from a server could have been delayed long
+     * enough for the deadline to expire.
+     */
+    DEADLINE_EXCEEDED = 4,
+    /**
+     * Some requested entity (e.g., file or directory) was not found.
+     */
+    NOT_FOUND = 5,
+    /**
+     * Some entity that we attempted to create (e.g., file or directory)
+     * already exists.
+     */
+    ALREADY_EXISTS = 6,
+    /**
+     * The caller does not have permission to execute the specified
+     * operation.  PERMISSION_DENIED must not be used for rejections
+     * caused by exhausting some resource (use RESOURCE_EXHAUSTED
+     * instead for those errors).  PERMISSION_DENIED must not be
+     * used if the caller can not be identified (use UNAUTHENTICATED
+     * instead for those errors).
+     */
+    PERMISSION_DENIED = 7,
+    /**
+     * Some resource has been exhausted, perhaps a per-user quota, or
+     * perhaps the entire file system is out of space.
+     */
+    RESOURCE_EXHAUSTED = 8,
+    /**
+     * Operation was rejected because the system is not in a state
+     * required for the operation's execution.  For example, directory
+     * to be deleted may be non-empty, an rmdir operation is applied to
+     * a non-directory, etc.
+     *
+     * A litmus test that may help a service implementor in deciding
+     * between FAILED_PRECONDITION, ABORTED, and UNAVAILABLE:
+     *
+     *  - Use UNAVAILABLE if the client can retry just the failing call.
+     *  - Use ABORTED if the client should retry at a higher-level
+     *    (e.g., restarting a read-modify-write sequence).
+     *  - Use FAILED_PRECONDITION if the client should not retry until
+     *    the system state has been explicitly fixed.  E.g., if an "rmdir"
+     *    fails because the directory is non-empty, FAILED_PRECONDITION
+     *    should be returned since the client should not retry unless
+     *    they have first fixed up the directory by deleting files from it.
+     *  - Use FAILED_PRECONDITION if the client performs conditional
+     *    REST Get/Update/Delete on a resource and the resource on the
+     *    server does not match the condition. E.g., conflicting
+     *    read-modify-write on the same resource.
+     */
+    FAILED_PRECONDITION = 9,
+    /**
+     * The operation was aborted, typically due to a concurrency issue
+     * like sequencer check failures, transaction aborts, etc.
+     *
+     * See litmus test above for deciding between FAILED_PRECONDITION,
+     * ABORTED, and UNAVAILABLE.
+     */
+    ABORTED = 10,
+    /**
+     * Operation was attempted past the valid range.  E.g., seeking or
+     * reading past end of file.
+     *
+     * Unlike INVALID_ARGUMENT, this error indicates a problem that may
+     * be fixed if the system state changes. For example, a 32-bit file
+     * system will generate INVALID_ARGUMENT if asked to read at an
+     * offset that is not in the range [0,2^32-1], but it will generate
+     * OUT_OF_RANGE if asked to read from an offset past the current
+     * file size.
+     *
+     * There is a fair bit of overlap between FAILED_PRECONDITION and
+     * OUT_OF_RANGE.  We recommend using OUT_OF_RANGE (the more specific
+     * error) when it applies so that callers who are iterating through
+     * a space can easily look for an OUT_OF_RANGE error to detect when
+     * they are done.
+     */
+    OUT_OF_RANGE = 11,
+    /**
+     * Operation is not implemented or not supported/enabled in this service.
+     */
+    UNIMPLEMENTED = 12,
+    /**
+     * Internal errors.  Means some invariants expected by underlying
+     * system has been broken.  If you see one of these errors,
+     * something is very broken.
+     */
+    INTERNAL = 13,
+    /**
+     * The service is currently unavailable.  This is a most likely a
+     * transient condition and may be corrected by retrying with
+     * a backoff.
+     *
+     * See litmus test above for deciding between FAILED_PRECONDITION,
+     * ABORTED, and UNAVAILABLE.
+     */
+    UNAVAILABLE = 14,
+    /**
+     * Unrecoverable data loss or corruption.
+     */
+    DATA_LOSS = 15,
+    /**
+     * The request does not have valid authentication credentials for the
+     * operation.
+     */
+    UNAUTHENTICATED = 16,
+  }
+
+  /**
+   * Propagation flags: these can be bitwise or-ed to form the propagation option
+   * for calls.
+   *
+   * Users are encouraged to write propagation masks as deltas from the default.
+   * i.e. write `grpc.propagate.DEFAULTS & ~grpc.propagate.DEADLINE` to disable
+   * deadline propagation.
+   */
+  export enum propagate {
+    DEADLINE,
+    CENSUS_STATS_CONTEXT,
+    CENSUS_TRACING_CONTEXT,
+    CANCELLATION,
+    DEFAULTS,
+  }
+
+  /**
+   * Call error constants. Call errors almost always indicate bugs in the gRPC
+   * library, and these error codes are mainly useful for finding those bugs.
+   */
+  export enum callError  {
+    OK,
+    ERROR,
+    NOT_ON_SERVER,
+    NOT_ON_CLIENT,
+    ALREADY_INVOKED,
+    NOT_INVOKED,
+    ALREADY_FINISHED,
+    TOO_MANY_OPERATIONS,
+    INVALID_FLAGS,
+    INVALID_METADATA,
+    INVALID_MESSAGE,
+    NOT_SERVER_COMPLETION_QUEUE,
+    BATCH_TOO_BIG,
+    PAYLOAD_TYPE_MISMATCH,
+  }
+
+  /**
+   * Write flags: these can be bitwise or-ed to form write options that modify
+   * how data is written.
+   */
+  export enum writeFlags {
+    /**
+     * Hint that the write may be buffered and need not go out on the wire
+     * immediately. GRPC is free to buffer the message until the next non-buffered
+     * write, or until writes_done, but it need not buffer completely or at all.
+     */
+    BUFFER_HINT = 1,
+    /**
+     * Force compression to be disabled for a particular write
+     */
+    NO_COMPRESS,
+  }
+
+  /**
+   * Log verbosity constants. Maps setting names to code numbers.
+   */
+  export enum logVerbosity {
+    DEBUG,
+    INFO,
+    ERROR,
+  }
+
+  /**
+   * Credentials module
+   *
+   * This module contains factory methods for two different credential types:
+   * CallCredentials and ChannelCredentials. ChannelCredentials are things like
+   * SSL credentials that can be used to secure a connection, and are used to
+   * construct a Client object. CallCredentials genrally modify metadata, so they
+   * can be attached to an individual method call.
+   *
+   * CallCredentials can be composed with other CallCredentials to create
+   * CallCredentials. ChannelCredentials can be composed with CallCredentials
+   * to create ChannelCredentials. No combined credential can have more than
+   * one ChannelCredentials.
+   *
+   * For example, to create a client secured with SSL that uses Google
+   * default application credentials to authenticate:
+   *
+   * ```
+   * var channel_creds = credentials.createSsl(root_certs);
+   * (new GoogleAuth()).getApplicationDefault(function(err, credential) {
+   *   var call_creds = credentials.createFromGoogleCredential(credential);
+   *   var combined_creds = credentials.combineChannelCredentials(
+   *       channel_creds, call_creds);
+   *   var client = new Client(address, combined_creds);
+   * });
+   * ```
+   */
+  export const credentials: {
+    /**
+     * Create an SSL Credentials object. If using a client-side certificate, both
+     * the second and third arguments must be passed.
+     * @param rootCerts The root certificate data
+     * @param privateKey The client certificate private key, if applicable
+     * @param certChain The client certificate cert chain, if applicable
+     * @return The SSL Credentials object
+     */
+    createSsl(rootCerts?: Buffer, privateKey?: Buffer, certChain?: Buffer): ChannelCredentials;
+
+    /**
+     * Create a gRPC credentials object from a metadata generation function. This
+     * function gets the service URL and a callback as parameters. The error
+     * passed to the callback can optionally have a 'code' value attached to it,
+     * which corresponds to a status code that this library uses.
+     * @param metadataGenerator The function that generates metadata
+     * @return The credentials object
+     */
+    createFromMetadataGenerator(metadataGenerator: metadataGenerator): CallCredentials;
+
+    /**
+     * Create a gRPC credential from a Google credential object.
+     * @param googleCredential The Google credential object to use
+     * @return The resulting credentials object
+     */
+    createFromGoogleCredential(googleCredential: GoogleCredential): CallCredentials;
+
+    /**
+     * Combine a ChannelCredentials with any number of CallCredentials into a single
+     * ChannelCredentials object.
+     * @param channelCredential The ChannelCredentials to start with
+     * @param credentials The CallCredentials to compose
+     * @return A credentials object that combines all of the input credentials
+     */
+    combineChannelCredentials(channelCredential: ChannelCredentials, ...credentials: CallCredentials[]): ChannelCredentials;
+
+    /**
+     * Combine any number of CallCredentials into a single CallCredentials object
+     * @param credentials The CallCredentials to compose
+     * @return A credentials object that combines all of the input credentials
+     */
+    combineCallCredentials(...credentials: CallCredentials[]): CallCredentials;
+
+    /**
+     * Create an insecure credentials object. This is used to create a channel that
+     * does not use SSL. This cannot be composed with anything.
+     * @return The insecure credentials object
+     */
+    createInsecure(): ChannelCredentials;
+  };
+
+  /**
+   * Metadata generator function.
+   */
+  export type metadataGenerator = (params: { service_url: string }, callback: (error: Error | null, metadata?: Metadata) => void) => void;
+
+  /**
+   * This cannot be constructed directly. Instead, instances of this class should
+   * be created using the factory functions in `grpc.credentials`
+   */
+  export class ChannelCredentials {}
+
+  /**
+   * This cannot be constructed directly. Instead, instances of this class should
+   * be created using the factory functions in `grpc.credentials`
+   */
+  export class CallCredentials {}
+
+  /**
+   * Google credential from https://github.com/google/google-auth-library-nodejs lib.
+   * The object definition is copied from `ts/lib/auth/credentials.ts`
+   */
+  export interface GoogleCredential {
+      refresh_token?: string;
+      expiry_date?: number;
+      access_token?: string;
+      token_type?: string;
+  }
+
+  /**
+   * Creates a constructor for a client with the given methods, as specified in
+   * the methods argument. The resulting class will have an instance method for
+   * each method in the service, which is a partial application of one of the
+   * `grpc.Client` request methods, depending on `requestSerialize`
+   * and `responseSerialize`, with the `method`, `serialize`, and `deserialize`
+   * arguments predefined.
+   * @param methods An object mapping method names to method attributes
+   * @param serviceName The fully qualified name of the service
+   * @param classOptions An options object.
+   * @return New client constructor, which is a subclass of `grpc.Client`, and
+   * has the same arguments as that constructor.
+   */
+  export function makeGenericClientConstructor(
+    methods: ServiceDefinition,
+    serviceName: string,
+    classOptions: GenericClientOptions,
+  ): typeof Client;
+
+  /**
+   * Options for generic client constructor.
+   */
+  export interface GenericClientOptions {
+    /**
+     * Indicates that the old argument order should be used for methods, with
+     * optional arguments at the end instead of the callback at the end. This
+     * option is only a temporary stopgap measure to smooth an API breakage.
+     * It is deprecated, and new code should not use it.
+     */
+    deprecatedArgumentOrder?: boolean;
+  }
+
+  /**
+   * Create a client with the given methods
+   */
+  export class Client {
+    /**
+     * A generic gRPC client. Primarily useful as a base class for generated clients
+     * @param address Server address to connect to
+     * @param credentials Credentials to use to connect to the server
+     * @param {Object} options Options to apply to channel creation
+     */
+    constructor(address: string, credentials: ChannelCredentials, options?: object)
+
+    /**
+     * Make a unary request to the given method, using the given serialize
+     * and deserialize functions, with the given argument.
+     * @param method The name of the method to request
+     * @param serialize The serialization function for inputs
+     * @param deserialize The deserialization function for outputs
+     * @param argument The argument to the call. Should be serializable with
+     *     serialize
+     * @param metadata Metadata to add to the call
+     * @param options Options map
+     * @param callback The callback to for when the response is received
+     * @return An event emitter for stream related events
+     */
+    makeUnaryRequest(
+      method: string,
+      serialize: serialize,
+      deserialize: deserialize,
+      argument: any | null,
+      metadata: Metadata | null,
+      options: CallOptions | null,
+      callback: requestCallback,
+    ): ClientUnaryCall;
+
+    /**
+     * Make a client stream request to the given method, using the given serialize
+     * and deserialize functions, with the given argument.
+     * @param method The name of the method to request
+     * @param serialize The serialization function for inputs
+     * @param deserialize The deserialization function for outputs
+     * @param metadata Array of metadata key/value pairs to add to the call
+     * @param options Options map
+     * @param callback The callback to for when the response is received
+     * @return An event emitter for stream related events
+     */
+    makeClientStreamRequest(
+      method: string,
+      serialize: serialize,
+      deserialize: deserialize,
+      metadata: Metadata | null,
+      options: CallOptions | null,
+      callback: requestCallback,
+    ): ClientWritableStream;
+
+    /**
+     * Make a server stream request to the given method, with the given serialize
+     * and deserialize function, using the given argument
+     * @param method The name of the method to request
+     * @param serialize The serialization function for inputs
+     * @param deserialize The deserialization function for outputs
+     * @param argument The argument to the call. Should be serializable with
+     *     serialize
+     * @param metadata Array of metadata key/value pairs to add to the call
+     * @param options Options map
+     * @return An event emitter for stream related events
+     */
+    makeServerStreamRequest(
+      method: string,
+      serialize: serialize,
+      deserialize: deserialize,
+      argument: any,
+      metadata?: Metadata | null,
+      options?: CallOptions | null,
+    ): ClientReadableStream;
+
+    /**
+     * Make a bidirectional stream request with this method on the given channel.
+     * @param method The name of the method to request
+     * @param serialize The serialization function for inputs
+     * @param deserialize The deserialization
+     *     function for outputs
+     * @param metadata Array of metadata key/value
+     *     pairs to add to the call
+     * @param options Options map
+     * @return An event emitter for stream related events
+     */
+    makeBidiStreamRequest(
+      method: string,
+      serialize: serialize,
+      deserialize: deserialize,
+      metadata?: Metadata | null,
+      options?: CallOptions | null,
+    ): ClientDuplexStream;
+
+    /**
+     * Close this client.
+     */
+    close(): void;
+
+    /**
+     * Return the underlying channel object for the specified client
+     * @return The channel
+     */
+    getChannel(): Channel;
+
+    /**
+     * Wait for the client to be ready. The callback will be called when the
+     * client has successfully connected to the server, and it will be called
+     * with an error if the attempt to connect to the server has unrecoverablly
+     * failed or if the deadline expires. This function will make the channel
+     * start connecting if it has not already done so.
+     * @param deadline When to stop waiting for a connection.
+     * @param callback The callback to call when done attempting to connect.
+     */
+    waitForReady(deadline: Deadline, callback: (error: Error | null) => void): void;
+  }
+
+  /**
+   * A gRPC channel.
+   */
+  export type Channel = any;
+
+  /**
+   * Options that can be set on a call.
+   */
+  export interface CallOptions {
+    /**
+     * The deadline for the entire call to complete.
+     */
+    deadline?: Deadline;
+    /**
+     * Server hostname to set on the call. Only meaningful if different from
+     * the server address used to construct the client.
+     */
+    host?: string;
+    /**
+     * Parent call. Used in servers when making a call as part of the process
+     * of handling a call. Used to propagate some information automatically,
+     * as specified by propagate_flags.
+     */
+    parent?: Call;
+    /**
+     * Indicates which properties of a parent call should propagate to this
+     * call. Bitwise combination of flags in `grpc.propagate`.
+     */
+    propagate_flags: number;
+    /**
+     * The credentials that should be used to make this particular call.
+     */
+    credentials: CallCredentials;
+  }
+
+  /**
+   * The deadline of an operation. If it is a date, the deadline is reached at
+   * the date and time specified. If it is a finite number, it is treated as
+   * a number of milliseconds since the Unix Epoch. If it is Infinity, the
+   * deadline will never be reached. If it is -Infinity, the deadline has already
+   * passed.
+   */
+  export type Deadline = number | Date;
+
+  /**
+   * Any client call type
+   */
+  type Call = ClientUnaryCall | ClientReadableStream | ClientWritableStream | ClientDuplexStream;
+
+  export class ClientUnaryCall {
+    /**
+     * An EventEmitter. Used for unary calls.
+     * @param call The call object associated with the request
+     */
+    constructor(call: any);
+
+    /**
+     * Cancel the ongoing call. Results in the call ending with a CANCELLED status,
+     * unless it has already ended with some other status.
+     */
+    cancel(): void;
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+  }
+
+  export class ClientReadableStream {
+    /**
+     * A stream that the client can read from. Used for calls that are streaming
+     * from the server side.
+     * @param call The call object to read data with
+     * @param deserialize Deserialization function for reads. Defaults to `identity`.
+     */
+    constructor(call: any, deserialize?: deserialize);
+
+    /**
+     * Cancel the ongoing call. Results in the call ending with a CANCELLED status,
+     * unless it has already ended with some other status.
+     */
+    cancel(): void;
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+  }
+
+  export class ClientWritableStream {
+    /**
+     * A stream that the client can write to. Used for calls that are streaming from
+     * the client side.
+     * @param call The call object to send data with
+     * @param serialize Serialization
+     *     function for writes. Defaults to `identity`.
+     */
+    constructor(call: any, serialize?: serialize);
+
+    /**
+     * Write a message to the request stream. If serializing the argument fails,
+     * the call will be cancelled and the stream will end with an error.
+     * @param message The message to write. Must be a valid argument to the
+     *     serialize function of the corresponding method
+     * @param flags Flags to modify how the message is written
+     * @param callback Callback for when this chunk of data is flushed
+     * @return As defined for [Writable]{@link external:Writable}
+     */
+    write(message: any, flags: writeFlags, callback: Function): boolean;
+
+    /**
+     * Cancel the ongoing call. Results in the call ending with a CANCELLED status,
+     * unless it has already ended with some other status.
+     */
+    cancel(): void;
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+  }
+
+  export class ClientDuplexStream {
+    /**
+     * A stream that the client can read from or write to. Used for calls with
+     * duplex streaming.
+     * @param {grpc.internal~Call} call Call object to proxy
+     * @param serialize Serialization function for requests. Defaults to `identity`.
+     * @param deserialize Deserialization function for responses. Defaults to `identity`.
+     */
+    constructor(call: any, serialize?: serialize | null, deserialize?: deserialize | null);
+
+    /**
+     * Write a message to the request stream. If serializing the argument fails,
+     * the call will be cancelled and the stream will end with an error.
+     * @param message The message to write. Must be a valid argument to the
+     *     serialize function of the corresponding method
+     * @param flags Flags to modify how the message is written
+     * @param callback Callback for when this chunk of data is flushed
+     * @return As defined for [Writable]{@link external:Writable}
+     */
+    write(message: any, flags: writeFlags, callback: Function): boolean;
+
+    /**
+     * Cancel the ongoing call. Results in the call ending with a CANCELLED status,
+     * unless it has already ended with some other status.
+     */
+    cancel(): void;
+
+    /**
+     * Get the endpoint this call/stream is connected to.
+     * @return The URI of the endpoint
+     */
+    getPeer(): string;
+  }
+
+  /**
+   * Client request callback
+   * @param error The error, if the call failed
+   * @param value The response value, if the call succeeded
+   */
+  export type requestCallback = (error: Error | null, value: any) => void;
+
+  /**
+   * Return the underlying channel object for the specified client
+   * @see grpc.Client#getChannel
+   * @param client The client
+   * @return The channel
+   */
+  export function getClientChannel(client: Client): Channel;
+
+  /**
+   * Wait for the client to be ready. The callback will be called when the
+   * client has successfully connected to the server, and it will be called
+   * with an error if the attempt to connect to the server has unrecoverablly
+   * failed or if the deadline expires. This function will make the channel
+   * start connecting if it has not already done so.
+   * @see grpc.Client#waitForReady
+   * @param client The client to wait on
+   * @param deadline When to stop waiting for a connection. Pass Infinity to
+   * wait forever.
+   * @param callback The callback to call when done attempting to connect.
+   */
+  export function waitForClientReady(client: Client, deadline: Deadline, callback: (error: Error | null) => void): void;
+
+  /**
+   * Close client.
+   * @param clientObj The client to close
+   */
+  export function closeClient(clientObj: Client): void;
+}
diff --git a/packages/grpc-native-core/package.json b/packages/grpc-native-core/package.json
index 4a0c220d..90acad8c 100644
--- a/packages/grpc-native-core/package.json
+++ b/packages/grpc-native-core/package.json
@@ -67,6 +67,7 @@
     "binding.gyp"
   ],
   "main": "index.js",
+  "typings": "src/index.d.ts",
   "license": "Apache-2.0",
   "jshintConfig": {
     "bitwise": true,