Pexafy Server

CI License: MIT

Stock photo search for AI assistants. An MCP server that lets Claude, ChatGPT or any MCP client search a library of royalty-free images — by describing a scene in plain language, from an example image, or "more like this" — and render the results as a thumbnail grid inside the conversation.

Remote MCP, OAuth, no API key to paste, 3 tools, images rendered inline.

The product page, with the same steps in twenty-three languages, is at pexafy.com/mcp.

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Use it (nothing to install)

A hosted server runs at:

https://mcp.pexafy.com/mcp

It speaks Streamable HTTP and authenticates with OAuth 2.1 — you sign in to Pexafy in a browser window and the connector receives its own credentials. There is no API key to generate, paste into a JSON file, or rotate later.

Claude (web and desktop)

1. Open Settings → Connectors (on Team/Enterprise, an owner adds it once under Organization settings → Connectors).
2. Click Add custom connector.
3. Paste https://mcp.pexafy.com/mcp and confirm.
4. Sign in to Pexafy in the window that opens. Done — ask Claude for a photo.

Claude Code

claude mcp add --transport http pexafy https://mcp.pexafy.com/mcp

Any other MCP client

Point it at the same URL with the streamable-http transport. Clients that don't implement OAuth can authenticate instead with a Pexafy API key sent as Authorization: Bearer <key> or x-api-key: <key> — get one from the dashboard.

Liveness: GET /health (public, no auth).

Also listed in the official MCP registry as com.pexafy/pexafy-mcp, and on Smithery — where a hosted gateway URL is available for clients that prefer it.

What it costs

The Free plan covers 5,000 searches a month with one connector — enough for regular use, no card required. Higher tiers are on the pricing page. When you hit a limit, the assistant tells you in-chat instead of failing with an opaque error.

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Tools

Three read-only tools. No write scope, no account mutation.

search_photos — semantic text search

Describe the scene in a full sentence; Pexafy is semantic, so sentences beat keywords. All parameters are optional, but pass either q or at least one filter.

Parameter	Type	Notes
q	string	The scene, in natural language. Max 500 characters.
color_name	string	One of: red, orange, yellow, green, blue, purple, pink, brown, black, white, gray, teal, beige, gold, navy. Excludes color_hex.
color_hex	string	e.g. #1E90FF. Excludes color_name.
color_tolerance	integer	0 (exact) to 255 (loose). Default 20. Only with color_hex.
orientation	string[]	landscape, portrait, square.
source	string[]	Unsplash, Pexels, Pixabay, Kaboompics, Burst, StockSnap, Picjumbo, Skitterphoto, NegativeSpace.
license_type	string[]	free, cc0.
photographer	string	Exact username.
after_date	string	YYYY-MM-DD. Published on or after.
cursor	string	pagination.next_cursor from a previous response.

search_photos_by_image — visual search from an example

Finds photos that look like a reference image, optionally tweaked in words ("like this, but at night").

Parameter	Type	Notes
image_url	string	Public http(s) URL of the reference image.
image_file	object	Auto-filled by hosts that support uploads (e.g. ChatGPT).
image_base64	string	Raw base64 bytes, for programmatic clients.
q	string	Text to combine with the image ("but with hands raised").
text_alpha	number	Weight of q against the image.
orientation, source, color_name, license_type, photographer, after_date	string	Same filters as above.
cursor	string	Pagination token.

One of image_url, image_file or image_base64 is required. Images are fetched server-side; max 20 MB.

get_similar_photos — more like this

Parameter	Type	Notes
photo_id	string	Required. A photo's UUID, taken from a previous result.
cursor	string	Pagination token.

What comes back

Every photo carries its id, URLs at several sizes, dimensions, dominant colour, orientation, source, licence, photographer, and an attribution string to display as credit — enough for the assistant to reason about the results rather than just list them.

Results are numbered #1, #2, …, so you refer to a photo the way you would in conversation. No ids to copy around:

In clients that support MCP Apps, clicking a thumbnail opens a detail panel with the full metadata — no extra call, it is all in the tool result already:

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Self-host

You don't need to — the hosted server above is the intended way in. But the server is a thin, plain client of the Pexafy API, so you can run your own against your own key.

Requires Python 3.12+.

git clone https://github.com/Pexafy/pexafy-mcp.git && cd pexafy-mcp
./run.sh setup        # venv + editable install + seed .env
# edit .env — set PEXAFY_API_KEY
./run.sh dev          # stdio, for Claude Desktop / Claude Code

With the installed console script (pip install .):

pexafy-mcp                             # stdio (default)
PEXAFY_MCP_TRANSPORT=http pexafy-mcp   # remote Streamable HTTP

Claude Desktop / Claude Code, over stdio:

{
  "mcpServers": {
    "pexafy": {
      "command": "pexafy-mcp",
      "env": { "PEXAFY_API_KEY": "pexafy_api_…" }
    }
  }
}

Docker, over HTTP — see docker-compose.example.yml:

docker compose -f docker-compose.example.yml up -d
curl localhost:8765/health

The image itself defaults to stdio, the transport an MCP client uses to drive a container, so it also works directly:

docker run -i --rm pexafy-mcp

That answers initialize and tools/list with no API key and no network — the tools come from the vendored OpenAPI snapshot. A key is only needed to run a search. Serving over HTTP is a matter of setting the transport, which both compose files do.

Configuration

Every setting is an environment variable, and every one of them is optional: with none set, pexafy-mcp starts on stdio and answers initialize and tools/list offline. Two are worth knowing about.

Variable	Default	Purpose
PEXAFY_MCP_TRANSPORT	stdio	stdio for a local client, http to serve remotely
PEXAFY_API_BASE_URL	http://localhost:8000	Pexafy API root — point it at https://api.pexafy.com, or at your own deployment

The rest belongs to a deployment rather than to someone running the container, and lives in .env.example: a fallback PEXAFY_API_KEY for stdio use when the client sends no key of its own, PEXAFY_THUMB_BASE_URL and PEXAFY_THUMB_HMAC_SECRET to sign the thumbnails behind the inline grid, and PEXAFY_OAUTH_* with MCP_RESOLVE_SECRET to run the HTTP transport as an OAuth resource server. None of them is needed to start the server.

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How it works

src/pexafy_mcp/
├── server.py     # entry point: builds the server, wires hooks, custom tools, /health
├── tooling.py    # tunes the OpenAPI-derived tools for an LLM (descriptions, value sets)
├── widget.py     # MCP Apps UI resource — the inline result grid (self-contained HTML)
├── previews.py   # signs the thumbnail URLs injected into each result
├── limits.py     # turns plan-limit (429) responses into in-chat upgrade nudges
├── auth.py       # per-user auth: OAuth Resource Server or forwarded API key
└── assets/       # vendored, shipped with the package:
    ├── openapi.json          # OpenAPI snapshot the tools are generated from
    ├── facets.json           # evolving source/license value sets
    └── ext_apps_bundle.js    # @modelcontextprotocol/ext-apps SDK (inlined in the widget)

• The tools are generated from the Pexafy OpenAPI spec via FastMCP.from_openapi(), so the API stays the single source of truth; tooling.py then reshapes them for an LLM — narrowing the surface to the search core, dropping parameters that mislead a model, and inlining the closed value sets so no facet lookup is ever needed.
• build_server() assembles everything. Importing the package has no side effects and does no network I/O: it reads the vendored assets/openapi.json and assets/facets.json. prepare.sh regenerates those.
• search_photos_by_image is hand-written: a chat assistant cannot upload a binary file to an MCP tool, so the tool takes an image URL and fetches it server-side.
• The inline grid is an MCP Apps UI resource. The ext-apps client is bundled and inlined, because the host's sandboxed iframe cannot fetch external scripts at runtime.

Development

./run.sh test         # offline test suite (pytest)
./run.sh inspect      # MCP Inspector
./prepare.sh          # maintainers: regenerate the vendored assets/

Contributions welcome — see CONTRIBUTING.md.

License

MIT — see LICENSE.

The package also redistributes third-party assets (the Inter typeface, the @modelcontextprotocol/ext-apps browser bundle and the libraries bundled into it), each under its own licence — see THIRD_PARTY_NOTICES.md.