diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 36a55084c..4bf3242a7 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -43,6 +43,7 @@ Any change that modifies the existing public API should be added to the relevant
 | ------: | :--------- |
 | v0.17.0 | quill      |
 | v0.18.0 | ridge      |
+| v0.19.0 | suit       |
 
 Please squash your changes into a single commit using a command like `git rebase -i upstream/<wip-branch>`.
 
@@ -65,13 +66,18 @@ By way of example, the [bilinearInterpolation method](https://github.com/lovell/
 ## Documentation
 
 The public API is documented with [JSDoc](http://usejsdoc.org/) annotated comments.
-These can be converted to Markdown by running:
 
+These can be converted to Markdown by running:
 ```sh
 npm run docs
 ```
 
-Please include documentation updates in any Pull Request that modifies the public API.
+The `types.d.ts` TypeScript declaration can be generated by running:
+```sh
+npm run types
+```
+
+Please include documentation and TypeScript declaration updates in any Pull Request that modifies the public API.
 
 ## Run the tests
 
diff --git a/docs/changelog.md b/docs/changelog.md
index 4afd0a620..d0c9dcb12 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -15,6 +15,10 @@ Requires libvips v8.4.2.
   Access to these is now via output format functions, for example `quality(n)`
     is now `jpeg({quality: n})` and/or `webp({quality: n})`.
 
+* Provide experimental, automated TypeScript declaration.
+  [#472](https://github.com/lovell/sharp/issues/472)
+  [@davidreher](https://github.com/davidreher)
+
 * Expose libvips' "centre" resize option to mimic \*magick's +0.5px convention.
   [#568](https://github.com/lovell/sharp/issues/568)
 
diff --git a/lib/types.d.ts b/lib/types.d.ts
new file mode 100644
index 000000000..1b92659da
--- /dev/null
+++ b/lib/types.d.ts
@@ -0,0 +1,962 @@
+/**
+ * @name sharp
+ *
+ * Constructor factory to create an instance of `sharp`, to which further methods are chained.
+ *
+ * JPEG, PNG or WebP format image data can be streamed out from this object.
+ * When using Stream based output, derived attributes are available from the `info` event.
+ *
+ * Implements the [stream.Duplex](http://nodejs.org/api/stream.html#stream_class_stream_duplex) class.
+ *
+ * @example
+ * sharp('input.jpg')
+ *   .resize(300, 200)
+ *   .toFile('output.jpg', function(err) {
+ *     // output.jpg is a 300 pixels wide and 200 pixels high image
+ *     // containing a scaled and cropped version of input.jpg
+ *   });
+ *
+ * @example
+ * // Read image data from readableStream,
+ * // resize to 300 pixels wide,
+ * // emit an 'info' event with calculated dimensions
+ * // and finally write image data to writableStream
+ * var transformer = sharp()
+ *   .resize(300)
+ *   .on('info', function(info) {
+ *     console.log('Image height is ' + info.height);
+ *   });
+ * readableStream.pipe(transformer).pipe(writableStream);
+ *
+ * @param {(Buffer|String)} [input] - if present, can be
+ *  a Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
+ *  a String containing the path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
+ *  JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data can be streamed into the object when null or undefined.
+ * @param {Object} [options] - if present, is an Object with optional attributes.
+ * @param {Number} [options.density=72] - integral number representing the DPI for vector images.
+ * @param {Object} [options.raw] - describes raw pixel image data. See `raw()` for pixel ordering.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare var sharp
+
+Constructor factory to create an instance of `sharp`, to which further methods are chained.
+
+JPEG, PNG or WebP format image data can be streamed out from this object.
+When using Stream based output, derived attributes are available from the `info` event.
+
+Implements the [stream.Duplex](http://nodejs.org/api/stream.html#stream_class_stream_duplex) class.: any;
+
+/**
+ * Pixel limits.
+ * @member
+ * @private
+ */
+declare var maximum: any;
+
+/**
+ * An EventEmitter that emits a `change` event when a task is either:
+ * - queued, waiting for _libuv_ to provide a worker thread
+ * - complete
+ * @member
+ * @example
+ * sharp.queue.on('change', function(queueLength) {
+ *   console.log('Queue contains ' + queueLength + ' task(s)');
+ * });
+ */
+declare var queue: any;
+
+/**
+ * Create Object containing input and input-related options.
+ * @private
+ */
+declare function _createInputDescriptor(): void;
+
+/**
+ * Handle incoming Buffer chunk on Writable Stream.
+ * @private
+ * @param {Buffer} chunk
+ * @param {String} encoding - unused
+ * @param {Function} callback
+ */
+declare function _write(chunk: Buffer, encoding: String, callback: (() => any)): void;
+
+/**
+ * Flattens the array of chunks accumulated in input.buffer.
+ * @private
+ */
+declare function _flattenBufferIn(): void;
+
+/**
+ * Are we expecting Stream-based input?
+ * @private
+ * @returns {Boolean}
+ */
+declare function _isStreamInput(): Boolean;
+
+/**
+ * Take a "snapshot" of the Sharp instance, returning a new instance.
+ * Cloned instances inherit the input of their parent instance.
+ * This allows multiple output Streams and therefore multiple processing pipelines to share a single input Stream.
+ *
+ * @example
+ * const pipeline = sharp().rotate();
+ * pipeline.clone().resize(800, 600).pipe(firstWritableStream);
+ * pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(secondWritableStream);
+ * readableStream.pipe(pipeline);
+ * // firstWritableStream receives auto-rotated, resized readableStream
+ * // secondWritableStream receives auto-rotated, extracted region of readableStream
+ *
+ * @returns {Sharp}
+ */
+declare function clone(): Sharp;
+
+/**
+ * Fast access to image metadata without decoding any compressed image data.
+ * A Promises/A+ promise is returned when `callback` is not provided.
+ *
+ * - `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
+ * - `width`: Number of pixels wide
+ * - `height`: Number of pixels high
+ * - `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568)
+ * - `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
+ * - `density`: Number of pixels per inch (DPI), if present
+ * - `hasProfile`: Boolean indicating the presence of an embedded ICC profile
+ * - `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
+ * - `orientation`: Number value of the EXIF Orientation header, if present
+ * - `exif`: Buffer containing raw EXIF data, if present
+ * - `icc`: Buffer containing raw [ICC](https://www.npmjs.com/package/icc) profile data, if present
+ *
+ * @example
+ * const image = sharp(inputJpg);
+ * image
+ *   .metadata()
+ *   .then(function(metadata) {
+ *     return image
+ *       .resize(Math.round(metadata.width / 2))
+ *       .webp()
+ *       .toBuffer();
+ *   })
+ *   .then(function(data) {
+ *     // data contains a WebP image half the width and height of the original JPEG
+ *   });
+ *
+ * @param {Function} [callback] - called with the arguments `(err, metadata)`
+ * @returns {Promise|Sharp}
+ */
+declare function metadata(callback?: (() => any)): (Promise|Sharp);
+
+/**
+ * Do not process input images where the number of pixels (width * height) exceeds this limit.
+ * Assumes image dimensions contained in the input metadata can be trusted.
+ * The default limit is 268402689 (0x3FFF * 0x3FFF) pixels.
+ * @param {(Number|Boolean)} limit - an integral Number of pixels, zero or false to remove limit, true to use default limit.
+ * @returns {Sharp}
+ * @throws {Error} Invalid limit
+ */
+declare function limitInputPixels(limit: (Number|Boolean)): Sharp;
+
+/**
+ * An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
+ * This will reduce memory usage and can improve performance on some systems.
+ * @param {Boolean} [sequentialRead=true]
+ * @returns {Sharp}
+ */
+declare function sequentialRead(sequentialRead?: Boolean): Sharp;
+
+/**
+ * Weighting to apply to image crop.
+ * @member
+ * @private
+ */
+declare var gravity: any;
+
+/**
+ * Strategies for automagic crop behaviour.
+ * @member
+ * @private
+ */
+declare var strategy: any;
+
+/**
+ * Reduction kernels.
+ * @member
+ * @private
+ */
+declare var kernel: any;
+
+/**
+ * Enlargement interpolators.
+ * @member
+ * @private
+ */
+declare var interpolator: any;
+
+/**
+ * Resize image to `width` x `height`.
+ * By default, the resized image is centre cropped to the exact size specified.
+ *
+ * Possible reduction kernels are:
+ * - `cubic`: Use a [Catmull-Rom spline](https://en.wikipedia.org/wiki/Centripetal_Catmull%E2%80%93Rom_spline).
+ * - `lanczos2`: Use a [Lanczos kernel](https://en.wikipedia.org/wiki/Lanczos_resampling#Lanczos_kernel) with `a=2`.
+ * - `lanczos3`: Use a Lanczos kernel with `a=3` (the default).
+ *
+ * Possible enlargement interpolators are:
+ * - `nearest`: Use [nearest neighbour interpolation](http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation).
+ * - `bilinear`: Use [bilinear interpolation](http://en.wikipedia.org/wiki/Bilinear_interpolation), faster than bicubic but with less smooth results.
+ * - `vertexSplitQuadraticBasisSpline`: Use the smoother [VSQBS interpolation](https://github.com/jcupitt/libvips/blob/master/libvips/resample/vsqbs.cpp#L48) to prevent "staircasing" when enlarging.
+ * - `bicubic`: Use [bicubic interpolation](http://en.wikipedia.org/wiki/Bicubic_interpolation) (the default).
+ * - `locallyBoundedBicubic`: Use [LBB interpolation](https://github.com/jcupitt/libvips/blob/master/libvips/resample/lbb.cpp#L100), which prevents some "[acutance](http://en.wikipedia.org/wiki/Acutance)" but typically reduces performance by a factor of 2.
+ * - `nohalo`: Use [Nohalo interpolation](http://eprints.soton.ac.uk/268086/), which prevents acutance but typically reduces performance by a factor of 3.
+ *
+ * @example
+ * sharp(inputBuffer)
+ *   .resize(200, 300, {
+ *     kernel: sharp.kernel.lanczos2,
+ *     interpolator: sharp.interpolator.nohalo
+ *   })
+ *   .background('white')
+ *   .embed()
+ *   .toFile('output.tiff')
+ *   .then(function() {
+ *     // output.tiff is a 200 pixels wide and 300 pixels high image
+ *     // containing a lanczos2/nohalo scaled version, embedded on a white canvas,
+ *     // of the image data in inputBuffer
+ *   });
+ *
+ * @param {Number} [width] - pixels wide the resultant image should be, between 1 and 16383 (0x3FFF). Use `null` or `undefined` to auto-scale the width to match the height.
+ * @param {Number} [height] - pixels high the resultant image should be, between 1 and 16383. Use `null` or `undefined` to auto-scale the height to match the width.
+ * @param {Object} [options]
+ * @param {String} [options.kernel='lanczos3'] - the kernel to use for image reduction.
+ * @param {String} [options.interpolator='bicubic'] - the interpolator to use for image enlargement.
+ * @param {Boolean} [options.centreSampling=false] - use *magick centre sampling convention instead of corner sampling.
+ * @param {Boolean} [options.centerSampling=false] - alternative spelling of centreSampling.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function resize(width?: Number, height?: Number, options?: { kernel: String, interpolator: String, centreSampling: Boolean, centerSampling: Boolean }): Sharp;
+
+/**
+ * Crop the resized image to the exact size specified, the default behaviour.
+ *
+ * Possible attributes of the optional `sharp.gravity` are `north`, `northeast`, `east`, `southeast`, `south`,
+ * `southwest`, `west`, `northwest`, `center` and `centre`.
+ *
+ * The experimental strategy-based approach resizes so one dimension is at its target length
+ * then repeatedly ranks edge regions, discarding the edge with the lowest score based on the selected strategy.
+ * - `entropy`: focus on the region with the highest [Shannon entropy](https://en.wikipedia.org/wiki/Entropy_%28information_theory%29).
+ * - `attention`: focus on the region with the highest luminance frequency, colour saturation and presence of skin tones.
+ *
+ * @example
+ * const transformer = sharp()
+ *   .resize(200, 200)
+ *   .crop(sharp.strategy.entropy)
+ *   .on('error', function(err) {
+ *     console.log(err);
+ *   });
+ * // Read image data from readableStream
+ * // Write 200px square auto-cropped image data to writableStream
+ * readableStream.pipe(transformer).pipe(writableStream);
+ *
+ * @param {String} [crop='centre'] - A member of `sharp.gravity` to crop to an edge/corner or `sharp.strategy` to crop dynamically.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function crop(crop?: String): Sharp;
+
+/**
+ * Preserving aspect ratio, resize the image to the maximum `width` or `height` specified
+ * then embed on a background of the exact `width` and `height` specified.
+ *
+ * If the background contains an alpha value then WebP and PNG format output images will
+ * contain an alpha channel, even when the input image does not.
+ *
+ * @example
+ * sharp('input.gif')
+ *   .resize(200, 300)
+ *   .background({r: 0, g: 0, b: 0, a: 0})
+ *   .embed()
+ *   .toFormat(sharp.format.webp)
+ *   .toBuffer(function(err, outputBuffer) {
+ *     if (err) {
+ *       throw err;
+ *     }
+ *     // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
+ *     // containing a scaled version, embedded on a transparent canvas, of input.gif
+ *   });
+ *
+ * @returns {Sharp}
+ */
+declare function embed(): Sharp;
+
+/**
+ * Preserving aspect ratio, resize the image to be as large as possible
+ * while ensuring its dimensions are less than or equal to the `width` and `height` specified.
+ *
+ * Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
+ *
+ * @example
+ * sharp(inputBuffer)
+ *   .resize(200, 200)
+ *   .max()
+ *   .toFormat('jpeg')
+ *   .toBuffer()
+ *   .then(function(outputBuffer) {
+ *     // outputBuffer contains JPEG image data no wider than 200 pixels and no higher
+ *     // than 200 pixels regardless of the inputBuffer image dimensions
+ *   });
+ *
+ * @returns {Sharp}
+ */
+declare function max(): Sharp;
+
+/**
+ * Preserving aspect ratio, resize the image to be as small as possible
+ * while ensuring its dimensions are greater than or equal to the `width` and `height` specified.
+ *
+ * Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
+ *
+ * @returns {Sharp}
+ */
+declare function min(): Sharp;
+
+/**
+ * Ignoring the aspect ratio of the input, stretch the image to
+ * the exact `width` and/or `height` provided via `resize`.
+ * @returns {Sharp}
+ */
+declare function ignoreAspectRatio(): Sharp;
+
+/**
+ * Do not enlarge the output image if the input image width *or* height are already less than the required dimensions.
+ * This is equivalent to GraphicsMagick's `>` geometry option:
+ * "*change the dimensions of the image only if its width or height exceeds the geometry specification*".
+ * @param {Boolean} [withoutEnlargement=true]
+ * @returns {Sharp}
+ */
+declare function withoutEnlargement(withoutEnlargement?: Boolean): Sharp;
+
+/**
+ * Overlay (composite) an image over the processed (resized, extracted etc.) image.
+ *
+ * The overlay image must be the same size or smaller than the processed image.
+ * If both `top` and `left` options are provided, they take precedence over `gravity`.
+ *
+ * @example
+ * sharp('input.png')
+ *   .rotate(180)
+ *   .resize(300)
+ *   .flatten()
+ *   .background('#ff6600')
+ *   .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
+ *   .sharpen()
+ *   .withMetadata()
+ *   .quality(90)
+ *   .webp()
+ *   .toBuffer()
+ *   .then(function(outputBuffer) {
+ *     // outputBuffer contains upside down, 300px wide, alpha channel flattened
+ *     // onto orange background, composited with overlay.png with SE gravity,
+ *     // sharpened, with metadata, 90% quality WebP image data. Phew!
+ *   });
+ *
+ * @param {(Buffer|String)} overlay - Buffer containing image data or String containing the path to an image file.
+ * @param {Object} [options]
+ * @param {String} [options.gravity='centre'] - gravity at which to place the overlay.
+ * @param {Number} [options.top] - the pixel offset from the top edge.
+ * @param {Number} [options.left] - the pixel offset from the left edge.
+ * @param {Boolean} [options.tile=false] - set to true to repeat the overlay image across the entire image with the given `gravity`.
+ * @param {Boolean} [options.cutout=false] - set to true to apply only the alpha channel of the overlay image to the input image, giving the appearance of one image being cut out of another.
+ * @param {Object} [options.raw] - describes overlay when using raw pixel data.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function overlayWith(overlay: (Buffer|String), options?: { gravity: String, top: Number, left: Number, tile: Boolean, cutout: Boolean, raw: Object }): Sharp;
+
+/**
+ * Rotate the output image by either an explicit angle
+ * or auto-orient based on the EXIF `Orientation` tag.
+ *
+ * Use this method without angle to determine the angle from EXIF data.
+ * Mirroring is supported and may infer the use of a flip operation.
+ *
+ * The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
+ *
+ * Method order is important when both rotating and extracting regions,
+ * for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
+ *
+ * @example
+ * const pipeline = sharp()
+ *   .rotate()
+ *   .resize(null, 200)
+ *   .toBuffer(function (err, outputBuffer, info) {
+ *     // outputBuffer contains 200px high JPEG image data,
+ *     // auto-rotated using EXIF Orientation tag
+ *     // info.width and info.height contain the dimensions of the resized image
+ *   });
+ * readableStream.pipe(pipeline);
+ *
+ * @param {Number} [angle=auto] 0, 90, 180 or 270.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function rotate(angle?: Number): Sharp;
+
+/**
+ * Extract a region of the image.
+ *
+ * - Use `extract` before `resize` for pre-resize extraction.
+ * - Use `extract` after `resize` for post-resize extraction.
+ * - Use `extract` before and after for both.
+ *
+ * @example
+ * sharp(input)
+ *   .extract({ left: left, top: top, width: width, height: height })
+ *   .toFile(output, function(err) {
+ *     // Extract a region of the input image, saving in the same format.
+ *   });
+ * @example
+ * sharp(input)
+ *   .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre })
+ *   .resize(width, height)
+ *   .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost })
+ *   .toFile(output, function(err) {
+ *     // Extract a region, resize, then extract from the resized image
+ *   });
+ *
+ * @param {Object} options
+ * @param {Number} options.left - zero-indexed offset from left edge
+ * @param {Number} options.top - zero-indexed offset from top edge
+ * @param {Number} options.width - dimension of extracted image
+ * @param {Number} options.height - dimension of extracted image
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function extract(options: { left: Number, top: Number, width: Number, height: Number }): Sharp;
+
+/**
+ * Flip the image about the vertical Y axis. This always occurs after rotation, if any.
+ * The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
+ * @param {Boolean} [flip=true]
+ * @returns {Sharp}
+ */
+declare function flip(flip?: Boolean): Sharp;
+
+/**
+ * Flop the image about the horizontal X axis. This always occurs after rotation, if any.
+ * The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
+ * @param {Boolean} [flop=true]
+ * @returns {Sharp}
+ */
+declare function flop(flop?: Boolean): Sharp;
+
+/**
+ * Sharpen the image.
+ * When used without parameters, performs a fast, mild sharpen of the output image.
+ * When a `sigma` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space.
+ * Separate control over the level of sharpening in "flat" and "jagged" areas is available.
+ *
+ * @param {Number} [sigma] - the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+ * @param {Number} [flat=1.0] - the level of sharpening to apply to "flat" areas.
+ * @param {Number} [jagged=2.0] - the level of sharpening to apply to "jagged" areas.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function sharpen(sigma?: Number, flat?: Number, jagged?: Number): Sharp;
+
+/**
+ * Blur the image.
+ * When used without parameters, performs a fast, mild blur of the output image.
+ * When a `sigma` is provided, performs a slower, more accurate Gaussian blur.
+ * @param {Number} [sigma] a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function blur(sigma?: Number): Sharp;
+
+/**
+ * Extends/pads the edges of the image with the colour provided to the `background` method.
+ * This operation will always occur after resizing and extraction, if any.
+ *
+ * @example
+ * // Resize to 140 pixels wide, then add 10 transparent pixels
+ * // to the top, left and right edges and 20 to the bottom edge
+ * sharp(input)
+ *   .resize(140)
+ *   .background({r: 0, g: 0, b: 0, a: 0})
+ *   .extend({top: 10, bottom: 20, left: 10, right: 10})
+ *   ...
+ *
+ * @param {(Number|Object)} extend - single pixel count to add to all edges or an Object with per-edge counts
+ * @param {Number} [extend.top]
+ * @param {Number} [extend.left]
+ * @param {Number} [extend.bottom]
+ * @param {Number} [extend.right]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function extend(extend: (Number|{ top: Number, left: Number, bottom: Number, right: Number })): Sharp;
+
+/**
+ * Merge alpha transparency channel, if any, with `background`.
+ * @param {Boolean} [flatten=true]
+ * @returns {Sharp}
+ */
+declare function flatten(flatten?: Boolean): Sharp;
+
+/**
+ * Trim "boring" pixels from all edges that contain values within a percentage similarity of the top-left pixel.
+ * @param {Number} [tolerance=10] value between 1 and 99 representing the percentage similarity.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function trim(tolerance?: Number): Sharp;
+
+/**
+ * Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma`
+ * then increasing the encoding (brighten) post-resize at a factor of `gamma`.
+ * This can improve the perceived brightness of a resized image in non-linear colour spaces.
+ * JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation
+ * when applying a gamma correction.
+ * @param {Number} [gamma=2.2] value between 1.0 and 3.0.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function gamma(gamma?: Number): Sharp;
+
+/**
+ * Produce the "negative" of the image.
+ * @param {Boolean} [negate=true]
+ * @returns {Sharp}
+ */
+declare function negate(negate?: Boolean): Sharp;
+
+/**
+ * Enhance output image contrast by stretching its luminance to cover the full dynamic range.
+ * @param {Boolean} [normalise=true]
+ * @returns {Sharp}
+ */
+declare function normalise(normalise?: Boolean): Sharp;
+
+/**
+ * Alternative spelling of normalise.
+ * @param {Boolean} [normalize=true]
+ * @returns {Sharp}
+ */
+declare function normalize(normalize?: Boolean): Sharp;
+
+/**
+ * Convolve the image with the specified kernel.
+ *
+ * @example
+ * sharp(input)
+ *   .convolve({
+ *     width: 3,
+ *     height: 3,
+ *     kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
+ *   })
+ *   .raw()
+ *   .toBuffer(function(err, data, info) {
+ *     // data contains the raw pixel data representing the convolution
+ *     // of the input image with the horizontal Sobel operator
+ *   });
+ *
+ * @param {Object} kernel
+ * @param {Number} kernel.width - width of the kernel in pixels.
+ * @param {Number} kernel.height - width of the kernel in pixels.
+ * @param {Array} kernel.kernel - Array of length `width*height` containing the kernel values.
+ * @param {Number} [kernel.scale=sum] - the scale of the kernel in pixels.
+ * @param {Number} [kernel.offset=0] - the offset of the kernel in pixels.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function convolve(kernel: { width: Number, height: Number, kernel: Array, scale: Number, offset: Number }): Sharp;
+
+/**
+ * Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
+ * @param {Number} [threshold=128] - a value in the range 0-255 representing the level at which the threshold will be applied.
+ * @param {Object} [options]
+ * @param {Boolean} [options.greyscale=true] - convert to single channel greyscale.
+ * @param {Boolean} [options.grayscale=true] - alternative spelling for greyscale.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function threshold(threshold?: Number, options?: { greyscale: Boolean, grayscale: Boolean }): Sharp;
+
+/**
+ * Perform a bitwise boolean operation with operand image.
+ *
+ * This operation creates an output image where each pixel is the result of
+ * the selected bitwise boolean `operation` between the corresponding pixels of the input images.
+ *
+ * @param {Buffer|String} operand - Buffer containing image data or String containing the path to an image file.
+ * @param {String} operator - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+ * @param {Object} [options]
+ * @param {Object} [options.raw] - describes operand when using raw pixel data.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function boolean(operand: (Buffer|String), operator: String, options?: { raw: Object }): Sharp;
+
+/**
+ * Colourspaces.
+ * @private
+ */
+declare var colourspace: any;
+
+/**
+ * Set the background for the `embed`, `flatten` and `extend` operations.
+ * The default background is `{r: 0, g: 0, b: 0, a: 1}`, black without transparency.
+ *
+ * Delegates to the _color_ module, which can throw an Error
+ * but is liberal in what it accepts, clipping values to sensible min/max.
+ * The alpha value is a float between `0` (transparent) and `1` (opaque).
+ *
+ * @param {String|Object} rgba - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameter
+ */
+declare function background(rgba: (String|Object)): Sharp;
+
+/**
+ * Convert to 8-bit greyscale; 256 shades of grey.
+ * This is a linear operation. If the input image is in a non-linear colour space such as sRGB, use `gamma()` with `greyscale()` for the best results.
+ * By default the output image will be web-friendly sRGB and contain three (identical) color channels.
+ * This may be overridden by other sharp operations such as `toColourspace('b-w')`,
+ * which will produce an output image containing one color channel.
+ * An alpha channel may be present, and will be unchanged by the operation.
+ * @param {Boolean} [greyscale=true]
+ * @returns {Sharp}
+ */
+declare function greyscale(greyscale?: Boolean): Sharp;
+
+/**
+ * Alternative spelling of `greyscale`.
+ * @param {Boolean} [grayscale=true]
+ * @returns {Sharp}
+ */
+declare function grayscale(grayscale?: Boolean): Sharp;
+
+/**
+ * Set the output colourspace.
+ * By default output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+ * @param {String} [colourspace] - output colourspace e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568)
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function toColourspace(colourspace?: String): Sharp;
+
+/**
+ * Alternative spelling of `toColourspace`.
+ * @param {String} [colorspace] - output colorspace.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function toColorspace(colorspace?: String): Sharp;
+
+/**
+ * Boolean operations for bandbool.
+ * @private
+ */
+declare var bool: any;
+
+/**
+ * Extract a single channel from a multi-channel image.
+ *
+ * @example
+ * sharp(input)
+ *   .extractChannel('green')
+ *   .toFile('input_green.jpg', function(err, info) {
+ *     // info.channels === 1
+ *     // input_green.jpg contains the green channel of the input image
+ *    });
+ *
+ * @param {Number|String} channel - zero-indexed band number to extract, or `red`, `green` or `blue` as alternative to `0`, `1` or `2` respectively.
+ * @returns {Sharp}
+ * @throws {Error} Invalid channel
+ */
+declare function extractChannel(channel: (Number|String)): Sharp;
+
+/**
+ * Join one or more channels to the image.
+ * The meaning of the added channels depends on the output colourspace, set with `toColourspace()`.
+ * By default the output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+ * Channel ordering follows vips convention:
+ * - sRGB: 0: Red, 1: Green, 2: Blue, 3: Alpha.
+ * - CMYK: 0: Magenta, 1: Cyan, 2: Yellow, 3: Black, 4: Alpha.
+ *
+ * Buffers may be any of the image formats supported by sharp: JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data.
+ * For raw pixel input, the `options` object should contain a `raw` attribute, which follows the format of the attribute of the same name in the `sharp()` constructor.
+ *
+ * @param {Array|String|Buffer} images - one or more images (file paths, Buffers).
+ * @param {Object} options - image options, see `sharp()` constructor.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function joinChannel(images: (Array|String|Buffer), options: Object): Sharp;
+
+/**
+ * Perform a bitwise boolean operation on all input image channels (bands) to produce a single channel output image.
+ *
+ * @example
+ * sharp('3-channel-rgb-input.png')
+ *   .bandbool(sharp.bool.and)
+ *   .toFile('1-channel-output.png', function (err, info) {
+ *     // The output will be a single channel image where each pixel `P = R & G & B`.
+ *     // If `I(1,1) = [247, 170, 14] = [0b11110111, 0b10101010, 0b00001111]`
+ *     // then `O(1,1) = 0b11110111 & 0b10101010 & 0b00001111 = 0b00000010 = 2`.
+ *   });
+ *
+ * @param {String} boolOp - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function bandbool(boolOp: String): Sharp;
+
+/**
+ * Write output image data to a file.
+ *
+ * If an explicit output format is not selected, it will be inferred from the extension,
+ * with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
+ * Note that raw pixel data is only supported for buffer output.
+ *
+ * A Promises/A+ promise is returned when `callback` is not provided.
+ *
+ * @param {String} fileOut - the path to write the image data to.
+ * @param {Function} [callback] - called on completion with two arguments `(err, info)`.
+ * `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
+ * @returns {Promise} - when no callback is provided
+ * @throws {Error} Invalid parameters
+ */
+declare function toFile(fileOut: String, callback?: (() => any)): Promise;
+
+/**
+ * Write output to a Buffer.
+ * By default, the format will match the input image. JPEG, PNG, WebP, and RAW are supported.
+ * `callback`, if present, gets three arguments `(err, buffer, info)` where:
+ * - `err` is an error message, if any.
+ * - `buffer` is the output image data.
+ * - `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
+ * A Promises/A+ promise is returned when `callback` is not provided.
+ *
+ * @param {Function} [callback]
+ * @returns {Promise} - when no callback is provided
+ */
+declare function toBuffer(callback?: (() => any)): Promise;
+
+/**
+ * Include all metadata (EXIF, XMP, IPTC) from the input image in the output image.
+ * The default behaviour, when `withMetadata` is not used, is to strip all metadata and convert to the device-independent sRGB colour space.
+ * This will also convert to and add a web-friendly sRGB ICC profile.
+ * @param {Object} [withMetadata]
+ * @param {Number} [withMetadata.orientation] value between 1 and 8, used to update the EXIF `Orientation` tag.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function withMetadata(withMetadata?: { orientation: Number }): Sharp;
+
+/**
+ * Use these JPEG options for output image.
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Boolean} [options.progressive=false] - use progressive (interlace) scan
+ * @param {String} [options.chromaSubsampling='4:2:0'] - set to '4:4:4' to prevent chroma subsampling when quality <= 90
+ * @param {Boolean} [trellisQuantisation=false] - apply trellis quantisation, requires mozjpeg
+ * @param {Boolean} [overshootDeringing=false] - apply overshoot deringing, requires mozjpeg
+ * @param {Boolean} [optimiseScans=false] - optimise progressive scans, forces progressive, requires mozjpeg
+ * @param {Boolean} [optimizeScans=false] - alternative spelling of optimiseScans
+ * @param {Boolean} [options.force=true] - force JPEG output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+declare function jpeg(options?: { quality: Number, progressive: Boolean, chromaSubsampling: String, force: Boolean }, trellisQuantisation?: Boolean, overshootDeringing?: Boolean, optimiseScans?: Boolean, optimizeScans?: Boolean): Sharp;
+
+/**
+ * Use these PNG options for output image.
+ * @param {Object} [options]
+ * @param {Boolean} [options.progressive=false] - use progressive (interlace) scan
+ * @param {Number} [options.compressionLevel=6] - zlib compression level
+ * @param {Boolean} [options.adaptiveFiltering=true] - use adaptive row filtering
+ * @param {Boolean} [options.force=true] - force PNG output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+declare function png(options?: { progressive: Boolean, compressionLevel: Number, adaptiveFiltering: Boolean, force: Boolean }): Sharp;
+
+/**
+ * Use these WebP options for output image.
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Boolean} [options.force=true] - force WebP output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+declare function webp(options?: { quality: Number, force: Boolean }): Sharp;
+
+/**
+ * Use these TIFF options for output image.
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Boolean} [options.force=true] - force TIFF output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+declare function tiff(options?: { quality: Number, force: Boolean }): Sharp;
+
+/**
+ * Force output to be raw, uncompressed uint8 pixel data.
+ * @returns {Sharp}
+ */
+declare function raw(): Sharp;
+
+/**
+ * Force output to a given format.
+ * @param {(String|Object)} format - as a String or an Object with an 'id' attribute
+ * @param {Object} options - output options
+ * @returns {Sharp}
+ * @throws {Error} unsupported format or options
+ */
+declare function toFormat(format: (String|Object), options: Object): Sharp;
+
+/**
+ * Use tile-based deep zoom (image pyramid) output.
+ * You can also use a `.zip` or `.szi` file extension with `toFile` to write to a compressed archive file format.
+ *
+ * @example
+ *  sharp('input.tiff')
+ *   .tile({
+ *     size: 512
+ *   })
+ *   .toFile('output.dz', function(err, info) {
+ *     // output.dzi is the Deep Zoom XML definition
+ *     // output_files contains 512x512 tiles grouped by zoom level
+ *   });
+ *
+ * @param {Object} [tile]
+ * @param {Number} [tile.size=256] tile size in pixels, a value between 1 and 8192.
+ * @param {Number} [tile.overlap=0] tile overlap in pixels, a value between 0 and 8192.
+ * @param {String} [tile.container='fs'] tile container, with value `fs` (filesystem) or `zip` (compressed file).
+ * @param {String} [tile.layout='dz'] filesystem layout, possible values are `dz`, `zoomify` or `google`.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+declare function tile(tile?: { size: Number, overlap: Number, container: String, layout: String }): Sharp;
+
+/**
+ * Update the output format unless options.force is false,
+ * in which case revert to input format.
+ * @private
+ * @param {String} formatOut
+ * @param {Object} [options]
+ * @param {Boolean} [options.force=true] - force output format, otherwise attempt to use input format
+ * @returns {Sharp}
+ */
+declare function _updateFormatOut(formatOut: String, options?: { force: Boolean }): Sharp;
+
+/**
+ * Update a Boolean attribute of the this.options Object.
+ * @private
+ * @param {String} key
+ * @param {Boolean} val
+ * @throws {Error} Invalid key
+ */
+declare function _setBooleanOption(key: String, val: Boolean): void;
+
+/**
+ * Called by a WriteableStream to notify us it is ready for data.
+ * @private
+ */
+declare function _read(): void;
+
+/**
+ * Invoke the C++ image processing pipeline
+ * Supports callback, stream and promise variants
+ * @private
+ */
+declare function _pipeline(): void;
+
+/**
+ * Gets, or when options are provided sets, the limits of _libvips'_ operation cache.
+ * Existing entries in the cache will be trimmed after any change in limits.
+ * This method always returns cache statistics,
+ * useful for determining how much working memory is required for a particular task.
+ *
+ * @example
+ * const stats = sharp.cache();
+ * @example
+ * sharp.cache( { items: 200 } );
+ * sharp.cache( { files: 0 } );
+ * sharp.cache(false);
+ *
+ * @param {Object|Boolean} options - Object with the following attributes, or Boolean where true uses default cache settings and false removes all caching.
+ * @param {Number} [options.memory=50] - is the maximum memory in MB to use for this cache
+ * @param {Number} [options.files=20] - is the maximum number of files to hold open
+ * @param {Number} [options.items=100] - is the maximum number of operations to cache
+ * @returns {Object}
+ */
+declare function cache(options: ({ memory: Number, files: Number, items: Number }|Boolean)): Object;
+
+/**
+ * Gets, or when a concurrency is provided sets,
+ * the number of threads _libvips'_ should create to process each image.
+ * The default value is the number of CPU cores.
+ * A value of `0` will reset to this default.
+ *
+ * The maximum number of images that can be processed in parallel
+ * is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
+ *
+ * This method always returns the current concurrency.
+ *
+ * @example
+ * const threads = sharp.concurrency(); // 4
+ * sharp.concurrency(2); // 2
+ * sharp.concurrency(0); // 4
+ *
+ * @param {Number} [concurrency]
+ * @returns {Number} concurrency
+ */
+declare function concurrency(concurrency?: Number): Number;
+
+/**
+ * Provides access to internal task counters.
+ * - queue is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
+ * - process is the number of resize tasks currently being processed.
+ *
+ * @example
+ * const counters = sharp.counters(); // { queue: 2, process: 4 }
+ *
+ * @returns {Object}
+ */
+declare function counters(): Object;
+
+/**
+ * Get and set use of SIMD vector unit instructions.
+ * Requires libvips to have been compiled with liborc support.
+ *
+ * Improves the performance of `resize`, `blur` and `sharpen` operations
+ * by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
+ *
+ * This feature is currently off by default but future versions may reverse this.
+ * Versions of liborc prior to 0.4.25 are known to segfault under heavy load.
+ *
+ * @example
+ * const simd = sharp.simd();
+ * // simd is `true` if SIMD is currently enabled
+ * @example
+ * const simd = sharp.simd(true);
+ * // attempts to enable the use of SIMD, returning true if available
+ *
+ * @param {Boolean} [simd=false]
+ * @returns {Boolean}
+ */
+declare function simd(simd?: Boolean): Boolean;
+
diff --git a/package.json b/package.json
index a460e83e0..57f16b068 100644
--- a/package.json
+++ b/package.json
@@ -35,9 +35,11 @@
     "test": "semistandard && cross-env VIPS_WARNING=0 nyc --reporter=lcov --branches=99 mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
     "test-leak": "./test/leak/leak.sh",
     "test-packaging": "./packaging/test-linux-x64.sh",
-    "docs": "for m in constructor input resize composite operation colour channel output utility; do documentation build --shallow --format=md lib/$m.js >docs/api-$m.md; done"
+    "docs": "for m in constructor input resize composite operation colour channel output utility; do documentation build --shallow --format=md lib/$m.js >docs/api-$m.md; done",
+    "types": "cd lib && jsdoc -d . -t ../node_modules/tsd-jsdoc constructor.js input.js resize.js composite.js operation.js colour.js channel.js output.js utility.js"
   },
-  "main": "lib/",
+  "main": "lib/index.js",
+  "types": "lib/types.d.ts",
   "repository": {
     "type": "git",
     "url": "git://github.com/lovell/sharp"
@@ -72,11 +74,13 @@
     "documentation": "^4.0.0-beta12",
     "exif-reader": "^1.0.1",
     "icc": "^0.0.2",
+    "jsdoc": "^3.4.2",
     "mocha": "^3.1.2",
     "node-cpplint": "^0.4.0",
     "nyc": "^8.4.0",
     "rimraf": "^2.5.4",
     "semistandard": "^9.1.0",
+    "tsd-jsdoc": "^1.0.1",
     "unzip": "^0.1.11"
   },
   "license": "Apache-2.0",