gimp-mcp

An MCP server that lets AI assistants (Claude Desktop, Claude Code, and any other MCP client) edit images with GIMP.

Unlike most GIMP MCP servers, gimp-mcp:

• is a plain npm package — run it with npx @volare-consulting/gimp-mcp, no Python environment;
• needs no custom GIMP plug-in — it drives GIMP's built-in headless Script-Fu server, keeping one GIMP process alive as a live session;
• works on Windows, macOS, and Linux, and points you to the right installer if GIMP isn't present (gimp_doctor / install_gimp).

The tools are atomic GIMP operations — the same single actions a person performs in the GIMP UI (open an image, add an alpha channel, fuzzy-select, clear, add a text layer, scale, export, …). The assistant composes them, and all state persists between calls (open images, selections, layers, colours) — exactly like working in GIMP. There are no "do-everything" wrapper tools.

Example — make a logo's background transparent and caption it, the way you would in GIMP:

open_image("logo.png")            -> image 1
add_alpha_channel(1)
fuzzy_select(1, x=4, y=4, threshold=0.2)   # magic-wand the corner background
edit_clear(1)                     # erase it to transparency
select_none(1)
add_text_layer(1, "Super Diego", font="Times New Roman", x=430, y=672)
merge_visible(1)                  # keep the alpha channel
export_image(1, "logo_final.png")

Requirements

• Node.js ≥ 20
• GIMP 3.x installed (verified against GIMP 3.2; the tools use the GIMP 3.0 PDB). See Installing GIMP.

Quick start

Add the server to your MCP client. For Claude Desktop, edit claude_desktop_config.json (a full example is in examples/claude_desktop_config.json):

{
  "mcpServers": {
    "gimp": {
      "command": "npx",
      "args": ["-y", "@volare-consulting/gimp-mcp"]
    }
  }
}

For Claude Code:

claude mcp add gimp -- npx -y @volare-consulting/gimp-mcp

Then ask your assistant to "check the GIMP setup" — it will call gimp_doctor. If GIMP is missing it will tell you exactly how to install it.

Installing GIMP

The recommended, all-platform option is the official installer:

Download GIMP: https://www.gimp.org/downloads/

Or use a package manager:

| OS | Command | | ------- | --------------------------------------------- | | Windows | winget install --id GIMP.GIMP -e | | macOS | brew install --cask gimp | | Linux | flatpak install -y flathub org.gimp.GIMP (or sudo apt install gimp) |

The gimp_doctor and install_gimp tools report this guidance for the OS you're on. For safety, the server never runs an installer itself — it only tells you how.

How GIMP is located

The server finds GIMP automatically, in this order:

1. The GIMP_CONSOLE_PATH environment variable, if set.
2. gimp-console / gimp-console-3.2 / gimp-console-3.0 / … on your PATH.
3. Well-known install locations:
   • Windows: %LOCALAPPDATA%\Programs\GIMP 3\bin\ (winget) and C:\Program Files\GIMP 3\bin\
   • macOS: /Applications/GIMP.app/Contents/MacOS/gimp-console
   • Linux: /usr/bin/gimp-console, and Flatpak (org.gimp.GIMP).

If your GIMP is elsewhere, set GIMP_CONSOLE_PATH to the full path of the gimp-console executable.

Tools

Each tool is one GIMP operation. Tools that act on a layer take a layerId (from get_image_info) and default to the image's top layer when omitted. All verified against GIMP 3.2.

Setup & session — gimp_doctor, gimp_version, install_gimp (instructions only), end_session (reset the live GIMP process).

Images — open_image, new_image, export_image, duplicate_image, close_image, list_images, get_image_info, list_fonts.

Selection — select_all, select_none, select_invert, select_rectangle, select_ellipse, select_by_color, fuzzy_select (magic wand), select_grow, select_shrink, select_feather. Selection tools take a mode (replace/add/subtract/ intersect).

Edit & context — edit_clear, edit_fill, bucket_fill, set_foreground, set_background, set_sample_threshold, set_opacity.

Layers — add_alpha_channel, new_layer, add_layer_from_file, add_text_layer (with font — see list_fonts), set_layer_opacity, set_layer_offsets, delete_layer, merge_visible (keeps alpha), flatten (drops alpha).

Transform — scale_image, crop_image, resize_canvas, rotate_image, flip_image.

Colour & filters — brightness_contrast, levels, hue_saturation, color_balance, desaturate, invert, posterize, threshold, convert_grayscale, and apply_gegl_filter — the generic filter tool (any gegl:* operation with its properties, e.g. gegl:gaussian-blur { "std-dev-x": 5, "std-dev-y": 5 }).

Escape hatch — run_script_fu — evaluate arbitrary Script-Fu in the same live session, mixing freely with the tools above.

How it works

On first use the server starts one gimp-console running GIMP's built-in Script-Fu TCP server and connects to it. Each tool sends a single Script-Fu (PDB) command over the socket and reads the result; the GIMP process stays alive, so every open image, selection, and layer persists between tool calls — a true session, not file-in / file-out. See the GIMP manual and the Script-Fu server docs.

First-start note: the very first session start on a freshly installed GIMP registers every plug-in and loads all data/fonts — 30-60s on Windows (longer on a cold cache). The server is started eagerly when the MCP launches to hide this, but the first tool call may still wait. After that, operations are near-instant (~10 ms each). Launching the GIMP GUI once after install also warms the caches.

Commands are serialized — each runs to completion before the next starts — so the stateful session never desyncs even when a client dispatches tool calls concurrently.

If the GIMP process exits mid-session (crash, a (gimp-quit), or a command that exceeds the 120s timeout), the session tears down and restarts automatically on the next tool call — but any images, selections, and layers from before the restart are gone, so previously returned image/layer IDs become invalid. Re-open your images and continue. end_session resets the session deliberately.

Security

This server runs GIMP with the privileges of the user who launched it, and exposes run_script_fu, which evaluates arbitrary Script-Fu (Scheme) in the live session. Script-Fu can read and write files anywhere the user can and can invoke plug-ins, so a connected MCP client effectively has the user's filesystem access. Only connect MCP clients you trust, and treat any model output that reaches run_script_fu as code, not data. See SECURITY.md.

Development

npm install
npm run build            # tsc -> dist/
npm test                 # vitest unit tests
npm run typecheck
npm run lint
node scripts/smoke.mjs    # list tools + run gimp_doctor against the built server

Configuration

| Variable | Purpose | | ------------------- | -------------------------------------------------------- | | GIMP_CONSOLE_PATH | Full path to gimp-console if it isn't auto-detected. | | GIMP_MCP_PORT | TCP port for the Script-Fu session (default 10008). | | GIMP_MCP_TIMEOUT_MS | Timeout for one-shot console calls like gimp_version (default 240000). | | GIMP_MCP_DEBUG | Set to 1 to log every Script-Fu command to stderr. |

License

MIT © Volare Consulting