@mindstone/mcp-server-gamma

@mindstone/mcp-server-gamma

Gamma MCP server for creating Gamma presentations, documents, webpages, and social posts, listing themes and folders, and polling async generation/export status.

Best for MCP hosts that want to create Gamma decks and exports from a local package using an API key they already manage.

Status

• Version: 0.4.1 · npm
• Auth: API key (GAMMA_API_KEY)
• Tools: 6 (themes, folders, generation)
• Surface: cloud-api
• Machine-readable: STATUS.json

Why this exists

Gamma's hosted MCP server is the easiest path for no-code and remote-connector flows. This package is for local MCP hosts that already manage npm packages and API keys.

It gives an assistant the useful Gamma creation loop: pick a theme or folder, start a deck/document/webpage generation, wait for it to finish, and return the Gamma link or exported PDF/PPTX. The benefit is simple: turn a prompt into a usable Gamma asset without leaving the host.

Example interaction

"Create a 10-slide investor update about Q4 results using our corporate theme and export it as PPTX."

Tools the host calls:

• gamma_list_themes — finds the custom theme ID.
• gamma_generate — starts a presentation generation with export_as: "pptx".
• gamma_get_status — polls until Gamma completes the deck and export.

Response (trimmed):

{
  "generation_id": "gen_123",
  "status": "completed",
  "gamma_url": "<untrusted-content source=\"gamma:generation.url\">https://gamma.app/docs/...</untrusted-content>",
  "pptx_url": "<untrusted-content source=\"gamma:generation.url\">https://...</untrusted-content>",
  "file_path": "/tmp/gamma_export_gen_123_abcd.pptx"
}

External strings (theme/folder names, theme keywords, status error text, and URLs) are returned inside <untrusted-content> envelopes so the model treats them as data, not instructions.

Requirements

• Node.js 20+
• npm

One-click install

After clicking the button, your host will prompt you to fill: GAMMA_API_KEY, GAMMA_EXPORT_POLL_INTERVAL_MS, GAMMA_EXPORT_POLL_MAX_ATTEMPTS, GAMMA_REQUEST_TIMEOUT_MS.

Manual config for Claude Desktop / Claude Code / Goose / Continue.dev (Gamma)

{
  "mcpServers": {
    "Gamma": {
      "command": "npx",
      "args": [
        "-y",
        "@mindstone/mcp-server-gamma"
      ],
      "env": {
        "GAMMA_API_KEY": "",
        "GAMMA_EXPORT_POLL_INTERVAL_MS": "5000",
        "GAMMA_EXPORT_POLL_MAX_ATTEMPTS": "12",
        "GAMMA_REQUEST_TIMEOUT_MS": "60000"
      }
    }
  }
}

Quick Start

Install & build

cd <path-to-repo>/connectors/gamma
npm install
npm run build

npx (once published)

npx -y @mindstone/mcp-server-gamma

Local

node dist/index.js

Configuration

Environment variables

• GAMMA_API_KEY — Gamma API key
• GAMMA_EXPORT_POLL_INTERVAL_MS — export poll interval in milliseconds (default: 5000)
• GAMMA_EXPORT_POLL_MAX_ATTEMPTS — maximum export poll attempts (default: 12)
• GAMMA_REQUEST_TIMEOUT_MS — optional override (positive integer ms, max 30 min) for the outbound HTTP request timeout applied to both Gamma API and host-bridge calls. Default: 60000 (60s). Raise this if you see TIMEOUT errors on slow submits; lower it if you want tighter bounds.
• MCP_HOST_BRIDGE_STATE — host-managed bridge state file used for credential management when a host provides one; not needed for ordinary manual setup.
• MINDSTONE_REBEL_BRIDGE_STATE — backwards-compatible alias for MCP_HOST_BRIDGE_STATE.

Host configuration examples

Claude Desktop / Cursor

{
  "mcpServers": {
    "Gamma": {
      "command": "npx",
      "args": ["-y", "@mindstone/mcp-server-gamma"],
      "env": {
        "GAMMA_API_KEY": "your-api-key"
      }
    }
  }
}

Local development (no npm publish needed)

{
  "mcpServers": {
    "Gamma": {
      "command": "node",
      "args": ["<path-to-repo>/connectors/gamma/dist/index.js"],
      "env": {
        "GAMMA_API_KEY": "your-api-key"
      }
    }
  }
}

Tools (6)

Configuration

• configure_gamma_api_key — Configure the Gamma API key

Listing

• gamma_list_themes — List available Gamma themes (custom and standard)
• gamma_list_folders — List folders in the user's Gamma workspace

Generation

• gamma_generate — Create AI-powered presentations, documents, webpages, or social posts
• gamma_create_from_template — Clone and modify an existing Gamma document using AI
• gamma_get_status — Poll the status of a Gamma generation

Security notes

• Gamma API calls use GAMMA_API_KEY as an x-api-key header.
• configure_gamma_api_key can store the key in memory, or hand it to a host bridge when MCP_HOST_BRIDGE_STATE is present.
• Host bridge requests, when configured, go to 127.0.0.1 using the token from the bridge state file.
• Theme and folder names and theme keyword arrays returned by gamma_list_themes / gamma_list_folders are workspace-authored text and are wrapped in <untrusted-content> envelopes so the model treats them as data, not instructions. Unknown vendor-added response fields are stripped by fail-closed Zod validation, and vendor error bodies are never written to logs or model-visible errors.
• PDF/PPTX exports are downloaded from Gamma-provided URLs into the system temp directory. Export URLs are validated before any outbound request: HTTPS only, no userinfo, private/loopback/reserved hosts rejected, and hosts restricted to gamma.app and its subdomains. Redirects are followed manually with every hop re-validated against the same checks, and downloads are written atomically (exclusive no-follow create at an unpredictable path, mode 0600).
• Generation can create content in the user's Gamma workspace, may consume Gamma credits, and can set workspace/external sharing options; the generation tools are annotated destructiveHint: true accordingly.

Licence

FSL-1.1-MIT — Functional Source License, Version 1.1, with MIT future licence. The software converts to MIT licence on 2030-04-08.