dcc-mcp-gimp

Production-oriented GIMP 3 adapter for the DCC Model Context Protocol ecosystem.

Illustrative workflow generated with OpenAI ImageGen from the retained source in docs/images/sources; it is not a GIMP screenshot or host-validation artifact.

The adapter keeps GIMP API ownership inside a persistent GIMP 3 Python plug-in. An authenticated loopback JSON-lines bridge accepts a fixed catalog of typed commands, bounds connections, requests, responses, queue depth, image size, layer traversal, paths, file size, and execution time, then marshals every host operation onto GIMP's GLib main thread. It exposes no arbitrary Python, Script-Fu, action, or PDB-procedure execution.

Install

pip install dcc-mcp-gimp
dcc-mcp-gimp-install
dcc-mcp-gimp-doctor

Set at least one allowed file root before launching GIMP and the MCP server:

export DCC_MCP_GIMP_ALLOWED_ROOTS=/absolute/project/root
dcc-mcp-gimp

On Windows, separate multiple roots with ;; on POSIX, use :. The plug-in and client share a per-user token at ~/.dcc-mcp/gimp-bridge-token by default. An explicit token may instead be supplied through DCC_MCP_GIMP_BRIDGE_TOKEN and must contain at least 32 characters. Token values are never returned by status or diagnostics.

Restart GIMP after installation, then invoke the registered persistent python-fu-dcc-mcp-gimp-bridge procedure. The MCP endpoint defaults to http://127.0.0.1:8767/mcp; the plug-in bridge defaults to 127.0.0.1:3848.

Typed capabilities

• Inspect bridge readiness, open images, active image metadata, and recursive layer trees.
• Create or open bounded images under configured roots.
• Create/select/fill/rename/show/hide/lock/fade/delete layers through typed parameters.
• Preserve layered work as XCF and export PNG, JPEG, WebP, or TIFF with byte counts and SHA-256 digests.
• Flatten only with confirm=true; overwrite only with overwrite=true.
• Close only bridge-opened displays, and require discard_changes=true for dirty images.

GIMP image and layer IDs are process-local and must be rediscovered after a restart. File paths outside configured roots are rejected; paths attached to untrusted user images are redacted to a basename.

Architecture and validation

The GIMP host remains the sole owner of image state and main-thread affinity. The Python package owns MCP lifecycle, typed Skill declarations, installation, diagnostics, and the authenticated bridge client. No generic code evaluation crosses this boundary.

python -m pip install -e ".[dev]"
python -m pytest
python -m ruff check src tests tools
python tools/lint_skills.py
python -m build
python -m twine check dist/*

The real-host acceptance script is tests/live_gimp_smoke.py. It creates a bounded layered image, exercises all typed commands, saves XCF, exports PNG, verifies both artifacts, reopens the XCF, and cleans up only bridge-owned displays.

Official references: GIMP 3 Python plug-ins, GIMP Image API, and GIMP file save/export API.