Mochify

mochify-cli

A command-line tool and MCP server for mochify.app — a fast, privacy-first image compression and conversion API powered by a native C++ engine.

Compress and convert images to modern formats (AVIF, JXL, WebP, Jpegli) from your terminal, work on PDFs, or give AI assistants like Claude direct access to the same engine over the Model Context Protocol — either as a local stdio server (mochify serve) or the hosted one at mcp.mochify.app, which needs no install at all.

Jump to: Installation · CLI usage · PDF processing · MCP server · Plans

Installation

macOS (Homebrew):

brew tap getmochify/mochify

brew install mochify

Windows (Scoop):

scoop bucket add mochify https://github.com/getmochify/scoop-mochify

scoop install mochify

Linux / WSL:

# x86_64

curl -L https://github.com/getmochify/mochify-cli/releases/latest/download/mochify-linux-x86_64 -o mochify chmod +x mochify sudo mv mochify /usr/local/bin/

arm64

curl -L https://github.com/getmochify/mochify-cli/releases/latest/download/mochify-linux-arm64 -o mochify chmod +x mochify sudo mv mochify /usr/local/bin/

Cargo (all platforms):

cargo install mochify

Requires Rust. Easiest option on Linux/WSL if you already have the toolchain.

Manual: All binaries at Releases.

From source:

cargo install --path .

Authentication

Sign in with your mochify.app account to unlock your full quota:

mochify auth login

This opens your browser, where you sign in and authorize the CLI. Credentials are saved automatically to ~/.config/mochify/credentials.toml — no environment variables or manual key copying required. Both the CLI and MCP server pick them up automatically.

On a machine without a browser (over SSH, say), sign in with a code instead — open the link it prints on any device and type the code:

mochify auth login --no-browser

mochify auth status   # check whether you're signed in

mochify auth logout # remove saved credentials

Without an account you get 3 images per batch (IP-based). With a free account: 25 images/month. Sign up at mochify.app.

CLI Usage

mochify [OPTIONS] <FILES>...

Options

Examples

# Convert to AVIF

mochify photo.jpg -t avif

Resize and convert to WebP

mochify photo.jpg -t webp -w 800

Batch convert a folder to AVIF at 1200px wide

mochify ./images/*.jpg -t avif -w 1200 -o ./compressed

Natural-language prompt — let the AI pick the right params

mochify photo.jpg -p "convert to avif, 1200px wide" mochify photo.jpg -p "optimise for eBay" mochify photo.jpg -p "remove background and convert to WebP" mochify photo.jpg -p "resize to 50%, strip EXIF, keep as WebP"

Custom output name

mochify photo.jpg -t webp -n hero mochify product.jpg -p "optimise for Shopify" -n product-main

Pipe file paths from stdin

find . -name "*.jpg" | mochify -t webp -o ./out cat images.txt | mochify -p "convert to avif 1200px wide" -o ./compressed ls *.heic | mochify -t jpg

Quality

Quality is chosen automatically unless you say otherwise.

# Fixed quality

mochify photo.jpg -t webp -q 70

Let saliency pick it — detailed subjects keep more, flat areas less

mochify photo.jpg -t avif --smart-compress

Smallest file to serve from a web server

mochify photo.jpg -t webp --optimize-for-web

Brighten a dark photo

mochify photo.jpg --brightness 30

Pixel-exact

mochify scan.png -t webp --lossless

--lossless only works for jxl, webp and png — jpg and avif are rejected before the request goes out. It overrides -q and --smart-compress, and the output is usually larger than the input: lossless preserves pixels, not file size. A source that is already lossy (JPEG, AVIF, HEIC) comes back as the best lossy encode instead, since nothing can restore what that file discarded — the CLI says so when that happens.

Cropping to a region

--crop finds the subject itself. --region is for when *you* — or the AI assistant driving the MCP server — already know which part of the picture you want:

# The bottom-left quarter

mochify photo.jpg --region 0,0.5,0.5,0.5

A region, then sized: -w/-H apply to the cropped part

mochify photo.jpg --region 0.2,0.1,0.6,0.8 -w 800 -t webp

The four numbers are x,y,width,height as fractions of the image (0 to 1), measured from the top-left of the picture as it displays — the right way up, even for a phone photo stored sideways. Fractions rather than pixels so the same box works whatever size the image is viewed at. A value above 1 is refused before the request goes out, since that is almost always a box in pixels. The region is cut first: -w/-H, --crop, --rotation and --remove-bg all act on it. --verbose prints the pixel rectangle that was actually cut.

Over MCP this is how an assistant can crop to *content* — "crop to the feet", "just the logo": it looks at the image itself, picks the box, and Mochify only ever receives the four numbers.

Redaction

Hide faces, number plates, addresses or anything else before an image goes anywhere:

# Every face, found automatically

mochify family.jpg --redact faces

A number plate, as a box (fractions of the upright image, like --region)

mochify car.jpg --redact 0.38,0.71,0.24,0.08

Both, softened with a blur instead of a solid fill

mochify street.jpg --redact "faces;0.38,0.71,0.24,0.08" --redact-style blur

Separate entries with ; — the , belongs to the box. fill (solid black) is the default and the one to use for anything that must stay secret; blur is for the look of a blurred face, and blurred text or faces can sometimes be recovered.

Redaction always strips metadata (EXIF can hold a thumbnail of the original) and removes any HDR gain map (which holds the scene's structure), even if you asked to keep them. faces is best-effort — it can miss small faces and side profiles — so the CLI says when it found none. Check the output before sharing it.

HDR (Ultra HDR gain maps)

--hdr controls the Ultra HDR / ISO 21496-1 gain map that makes a photo render with real headroom on an HDR display.

Only jpg output can carry a gain map (jxl carries HDR by a different route; avif, webp and png cannot), so pair it with -t jpg. It is also skipped alongside --clarity or --remove-bg, which change the base the gain map is a ratio to. The CLI reads the X-Mochify-HDR response header and tells you when the output ended up with no gain map.

# Keep the headroom an iPhone photo already captured, converting to JPEG

mochify IMG_1234.heic -t jpg --hdr

Give an SDR photo a gain map

mochify photo.jpg --hdr generate

Or just say so

mochify photo.jpg -p "make this HDR"

Output file naming

By default, when the output format and directory match the input, the result is saved as {name}_mochified.{ext} so it's always clear something happened. If that file already exists, a numeric suffix is added (_1, _2, etc.). When the format changes (e.g. .jpg → .webp), the extension change is already unambiguous so no suffix is added.

Use -n, --name to set an explicit base name: mochify photo.jpg -t webp -n hero saves hero.webp. The prompt path also supports this: mochify *.jpg -p "optimise for Shopify, name them product" will produce product.webp, product_1.webp, etc.

PDF processing

PDFs are detected automatically by the .pdf extension, and --op picks what to do with them. (PDFs and images can't be mixed in a single command — run them separately.)

create is the exception: its inputs are images, so there is nothing in a .jpg to route on. Pass --op create, or just say "pdf" in a prompt — mochify *.jpg -p "convert to pdf" builds one too.

| --page | create | fit (default), a4, `let