Mastodon MCP

A Model Context Protocol server that provides tools for interacting with Mastodon. Currently supports creating toots with optional media attachments.

Features

• Create toots with customizable visibility and content warnings

• Upload and attach media files (images, videos, audio)

• Add alt text/descriptions to media attachments

• Schedule toots for a future time

• Secure credential management using environment variables or 1Password CLI

Related MCP server: MCP Twitter

Prerequisites

• Node.js 18+

• pnpm

• A Mastodon account and API access token

• Optionally, 1Password CLI (op) installed and configured if using 1Password for credential management.

Installation

# Clone the repository
git clone [repository-url]
cd mastodon-mcp

# Install dependencies
pnpm install

# Build the project
pnpm build

Configuration

The tool requires a Mastodon API token. You can provide this token in one of the following ways:

1. Environment Variable (Recommended for simplicity): Set the MASTODON_ACCESS_TOKEN environment variable:

   export MASTODON_ACCESS_TOKEN="your_mastodon_api_token"

2. 1Password: Store your token at:

   • op://Personal/Floss.Social Key/notesPlain

You can optionally set the Mastodon instance URL via environment variable:

export MASTODON_INSTANCE_URL="https://your.instance.social"

If not set, it defaults to https://floss.social.

Usage

Start the MCP server:

pnpm start

The server exposes a single tool mastodon_create_toot with the following parameters:

• content (required): The text content of your toot

• visibility: One of "public", "unlisted", "private", or "direct" (default: "public")

• sensitive: Boolean flag for sensitive content (default: false)

• spoiler_text: Warning text shown before the content (default: "")

• media_file: Path to a media file to attach

• media_description: Alt text/description for the attached media

• scheduled_at: Optional ISO 8601 datetime to schedule the toot for a future time (e.g., "2024-07-04T10:00:00-07:00")

Example Usage with MCP Inspector

1. Start the inspector:

npx @modelcontextprotocol/inspector node dist/mcp-server.js

2. Open http://localhost:5173 in your browser

3. Use the tool with parameters like:

{
  "content": "Hello from MCP!",
  "visibility": "public",
  "media_file": "/path/to/image.jpg",
  "media_description": "A beautiful sunset",
  "scheduled_at": "2025-01-01T12:00:00Z"
}

Development

# Run in development mode with auto-reloading
pnpm dev

# Build the project
pnpm build

# Run the built server
pnpm start

Security

• No credentials are hardcoded in the codebase

• API tokens can be securely managed via environment variables or retrieved from 1Password.

• API responses are git-ignored to prevent accidental credential leaks

License

ISC