diff --git a/native_client/javascript/README.md b/native_client/javascript/README.md
index 89ebc594..2247cb02 100644
--- a/native_client/javascript/README.md
+++ b/native_client/javascript/README.md
@@ -1 +1,13 @@
 Full project description and documentation on GitHub: [https://github.com/mozilla/DeepSpeech](https://github.com/mozilla/DeepSpeech).
+
+## Generating TypeScript Type Definitions
+
+You can generate the TypeScript type declaration file using `dts-gen`.
+This requires a compiled/installed version of the DeepSpeech NodeJS client.
+
+To generate a new `index.d.ts` type declaration file, run:
+
+```sh
+npm install -g dts-gen
+dts-gen --module deepspeech --file index.d.ts
+```
diff --git a/native_client/javascript/index.d.ts b/native_client/javascript/index.d.ts
new file mode 100644
index 00000000..c944876d
--- /dev/null
+++ b/native_client/javascript/index.d.ts
@@ -0,0 +1,198 @@
+declare module 'deepspeech' {
+/**
+ * Stores text of an individual token, along with its timing information
+ */
+export interface TokenMetadata {
+    text: string;
+    timestep: number;
+    start_time: number;
+}
+
+/**
+ * A single transcript computed by the model, including a confidence value and
+ * the metadata for its constituent tokens.
+ */
+export interface CandidateTranscript {
+    tokens: TokenMetadata[];
+    confidence: number;
+}
+
+/**
+ * An array of CandidateTranscript objects computed by the model.
+ */
+export interface Metadata {
+    transcripts: CandidateTranscript[];
+}
+
+/**
+ * @class
+ * Provides an interface to a DeepSpeech stream. The constructor cannot be called
+ * directly, use :js:func:`Model.createStream`.
+ */
+export class Stream {}
+
+/**
+ * An object providing an interface to a trained DeepSpeech model.
+ *
+ * @param aModelPath The path to the frozen model graph.
+ *
+ * @throws on error
+ */
+export class Model {
+constructor(aModelPath: string)
+
+/**
+ * Get beam width value used by the model. If :js:func:Model.setBeamWidth was
+ * not called before, will return the default value loaded from the model file.
+ * 
+ * @return Beam width value used by the model.
+ */
+beamWidth(): number;
+
+/**
+ * Set beam width value used by the model.
+ * 
+ * @param The beam width used by the model. A larger beam width value generates better results at the cost of decoding time.
+ *
+ * @return Zero on success, non-zero on failure.
+ */
+setBeamWidth(aBeamWidth: number): number;
+
+/**
+ * Return the sample rate expected by the model.
+ *
+ * @return Sample rate.
+ */
+sampleRate(): number;
+
+/**
+ * Enable decoding using an external scorer.
+ *
+ * @param aScorerPath The path to the external scorer file.
+ *
+ * @return Zero on success, non-zero on failure (invalid arguments).
+ */
+enableExternalScorer(aScorerPath: string): number;
+
+/**
+ * Disable decoding using an external scorer.
+ *
+ * @return Zero on success, non-zero on failure (invalid arguments).
+ */
+disableExternalScorer(): number;
+
+/**
+ * Set hyperparameters alpha and beta of the external scorer.
+ *
+ * @param aLMAlpha The alpha hyperparameter of the CTC decoder. Language Model weight.
+ * @param aLMBeta The beta hyperparameter of the CTC decoder. Word insertion weight.
+ *
+ * @return Zero on success, non-zero on failure (invalid arguments).
+ */
+setScorerAlphaBeta(aLMAlpha: number, aLMBeta: number): number;
+
+/**
+ * Use the DeepSpeech model to perform Speech-To-Text.
+ *
+ * @param aBuffer A 16-bit, mono raw audio signal at the appropriate sample rate (matching what the model was trained on).
+ *
+ * @return The STT result. Returns undefined on error.
+ */
+stt(aBuffer: object): string;
+
+/**
+ * Use the DeepSpeech model to perform Speech-To-Text and output metadata
+ * about the results.
+ *
+ * @param aBuffer A 16-bit, mono raw audio signal at the appropriate sample rate (matching what the model was trained on).
+ * @param aNumResults Maximum number of candidate transcripts to return. Returned list might be smaller than this.
+ * Default value is 1 if not specified.
+ *
+ * @return :js:func:`Metadata` object containing multiple candidate transcripts. Each transcript has per-token metadata including timing information.
+ * The user is responsible for freeing Metadata by calling :js:func:`FreeMetadata`. Returns undefined on error.
+ */
+sttWithMetadata(aBuffer: object, aNumResults: number): Metadata;
+
+/**
+ * Create a new streaming inference state. One can then call :js:func:`Stream.feedAudioContent` and :js:func:`Stream.finishStream` on the returned stream object.
+ *
+ * @return a :js:func:`Stream` object that represents the streaming state.
+ *
+ * @throws on error
+ */
+createStream(): object;
+
+/**
+ * Feed audio samples to an ongoing streaming inference.
+ *
+ * @param aBuffer An array of 16-bit, mono raw audio samples at the
+ *                 appropriate sample rate (matching what the model was trained on).
+ */
+feedAudioContent(aBuffer: object): void;
+
+/**
+ * Compute the intermediate decoding of an ongoing streaming inference.
+ *
+ * @return The STT intermediate result.
+ */
+intermediateDecode(aSctx: object): string;
+
+/**
+ * Compute the intermediate decoding of an ongoing streaming inference, return results including metadata.
+ *
+ * @param aNumResults Maximum number of candidate transcripts to return. Returned list might be smaller than this. Default value is 1 if not specified.
+ *
+ * @return :js:func:`Metadata` object containing multiple candidate transcripts. Each transcript has per-token metadata including timing information. The user is responsible for freeing Metadata by calling :js:func:`FreeMetadata`. Returns undefined on error.
+ */
+intermediateDecodeWithMetadata (aNumResults: number): Metadata;
+
+/**
+ * Compute the final decoding of an ongoing streaming inference and return the result. Signals the end of an ongoing streaming inference.
+ *
+ * @return The STT result.
+ *
+ * This method will free the stream, it must not be used after this method is called.
+ */
+finishStream(): string;
+
+/**
+ * Compute the final decoding of an ongoing streaming inference and return the results including metadata. Signals the end of an ongoing streaming inference.
+ *
+ * @param aNumResults Maximum number of candidate transcripts to return. Returned list might be smaller than this. Default value is 1 if not specified.
+ *
+ * @return Outputs a :js:func:`Metadata` struct of individual letters along with their timing information. The user is responsible for freeing Metadata by calling :js:func:`FreeMetadata`.
+ *
+ * This method will free the stream, it must not be used after this method is called.
+ */
+finishStreamWithMetadata(aNumResults: number): Metadata;
+}
+
+/**
+ * Frees associated resources and destroys model object.
+ *
+ * @param model A model pointer returned by :js:func:`Model`
+ *
+ */
+export function FreeModel(model: Model): void;
+
+/**
+ * Free memory allocated for metadata information.
+ *
+ * @param metadata Object containing metadata as returned by :js:func:`Model.sttWithMetadata` or :js:func:`Model.finishStreamWithMetadata`
+ */
+export function FreeMetadata(metadata: Metadata): void;
+
+/**
+ * Destroy a streaming state without decoding the computed logits. This
+ * can be used if you no longer need the result of an ongoing streaming
+ * inference and don't want to perform a costly decode operation.
+ *
+ * @param stream A streaming state pointer returned by :js:func:`Model.createStream`.
+ */
+export function FreeStream(stream: object): void;
+
+/**
+ * Print version of this library and of the linked TensorFlow library on standard output.
+ */
+export function Version(): void;
+}
diff --git a/native_client/javascript/tsconfig.json b/native_client/javascript/tsconfig.json
new file mode 100644
index 00000000..a0ce2c4b
--- /dev/null
+++ b/native_client/javascript/tsconfig.json
@@ -0,0 +1,18 @@
+{
+    "compilerOptions": {
+        "baseUrl": ".",
+        "target": "es6",
+        "module": "commonjs",
+        "moduleResolution": "node",
+        "esModuleInterop": true,
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+    ]
+}
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