@upload-post/mcp

Official Model Context Protocol (MCP) server for Upload-Post.

Lets any MCP-compatible AI agent (Claude Desktop, Claude Code, Cursor, …) publish, schedule, analyze and manage social media across TikTok, Instagram, YouTube, LinkedIn, Facebook, Pinterest, Threads, Reddit, Bluesky, X, Google Business, Discord, Telegram and more with a single API key.

Built on top of the official upload-post SDK and the public Upload-Post REST API.

Two ways to use it

A) Local stdio (single-user) — simplest

The server runs on your machine, spawned by the MCP client. Add to ~/.claude/mcp.json (or Cursor settings, etc.):

{
  "mcpServers": {
    "upload-post": {
      "command": "npx",
      "args": ["-y", "@upload-post/mcp"],
      "env": { "UPLOAD_POST_API_KEY": "YOUR_API_KEY" }
    }
  }
}

Get your API key at https://app.upload-post.com → API Keys. Restart the client — you should see 45 upload-post tools.

B) Hosted HTTP (multi-tenant) — share one server with many users

Run the server on any Docker-capable host (Fly, Railway, Cloud Run, your own box…) and let each user connect with their own Upload-Post API key. The server stores nothing per user.

{
  "mcpServers": {
    "upload-post": {
      "url": "https://mcp.your-domain.com/mcp",
      "headers": {
        "Authorization": "ApiKey YOUR_OWN_UPLOAD_POST_API_KEY"
      }
    }
  }
}

Authorization: Bearer <key> is also accepted, for clients that only allow Bearer.

What can the agent do?

The server exposes Upload-Post API tools plus one ChatGPT App UI launcher.

Async uploads return a request_id. The agent should poll get_status until success: true.

FFmpeg jobs accept one public URL through input_url or multiple URLs through files. Poll get_ffmpeg_job until completion, then call download_ffmpeg_result; it returns the result URL without streaming the processed binary through MCP.

ChatGPT video upload UI

open_upload_studio renders a ChatGPT Apps component for file-based video publishing. The widget creates a short-lived Upload-Post/R2 staging upload, PUTs the local video directly to R2, completes the upload, then calls upload_video with the returned temporary media URL.

The staging object is deleted after 24 hours whether it is used or not. Scheduled/queued posts remain safe because upload_video copies the temporary URL into the existing durable scheduler storage before execution.

Claude and other MCP clients can use the same flow without the ChatGPT UI: call create_media_upload, PUT the file to upload_url, call complete_media_upload, then pass media_url to upload_video.

Set UPLOAD_POST_R2_CONNECT_DOMAINS on the MCP host to the comma-separated origins used by the backend's R2 signed URLs when they differ from the defaults (for example https://<account>.r2.cloudflarestorage.com,https://<bucket>.<account>.r2.cloudflarestorage.com) so the ChatGPT component CSP allows the browser PUT.

The R2 bucket CORS policy must allow browser uploads. A restrictive policy can include your actual widget origin; for fastest validation, use:

[
  {
    "AllowedOrigins": ["*"],
    "AllowedMethods": ["PUT", "GET", "HEAD"],
    "AllowedHeaders": ["*"],
    "ExposeHeaders": ["ETag"],
    "MaxAgeSeconds": 3600
  }
]

Local / development

git clone https://github.com/Upload-Post/upload-post-mcp.git
cd upload-post-mcp
npm install
npm run build

# stdio (default — used by Claude Desktop, Cursor)
UPLOAD_POST_API_KEY=... node dist/index.js

# HTTP streamable (for hosted deployments)
UPLOAD_POST_API_KEY=... node dist/index.js --http --port 8080

Inspect the live tool surface with the official inspector:

npx @modelcontextprotocol/inspector node dist/index.js

Configuration

CLI flags:

• --http — start the streamable HTTP transport instead of stdio
• --port <n> — port for HTTP mode

HTTP endpoints:

• POST /mcp — JSON-RPC over MCP streamable HTTP. Requires Authorization: ApiKey <key> (or Bearer <key>) on every request. The key is the user's own Upload-Post API key; the server uses it only for that session and stores nothing.
• GET /healthz — liveness probe, always open. Returns {"ok":true}.

Auth model in --http mode is the same pattern Resend, Tavily, Brave Search and other API-key-native services use for their hosted MCPs: the upstream key is the auth.

Deploy with Docker

The repo ships with a multi-stage Dockerfile and a .dockerignore. On any Docker-capable PaaS (Fly.io, Railway, Render, Cloud Run, fly machines, your own box…):

1. Point the PaaS at this repo and select Dockerfile as the build pack.
2. Port: 8080 (matches EXPOSE 8080).
3. Environment variables: none are required. Optionally set UPLOAD_POST_BASE_URL if you point at staging.
4. Health check path: /healthz (HTTP, port 8080).
5. Domain: attach a domain, e.g. mcp.your-domain.com, and provision TLS (most PaaS do this automatically via Let's Encrypt).

Deploy. The server is now ready for any number of users. Each user adds the endpoint to their MCP client config with their own Upload-Post API key:

{
  "mcpServers": {
    "upload-post": {
      "url": "https://mcp.your-domain.com/mcp",
      "headers": {
        "Authorization": "ApiKey USER_OWN_UPLOAD_POST_API_KEY"
      }
    }
  }
}

Without an Authorization header the server returns 401. The header is the only credential — invalid Upload-Post keys will surface as upstream errors on the first tool call.

Local test of the production image:

docker build -t upload-post-mcp .
docker run --rm -p 8080:8080 upload-post-mcp
curl http://localhost:8080/healthz   # → {"ok":true}
curl -i -X POST http://localhost:8080/mcp \
  -H "content-type: application/json" \
  -d '{}'                               # → 401 (no Authorization)

Tips for prompting the agent

• Prefer public URLs over local paths when uploading — local paths only work if the MCP server runs on the user's machine.
• In ChatGPT Apps, prefer open_upload_studio for user-selected video files. It avoids local-path handoff issues by uploading to short-lived Upload-Post/R2 staging, then passing a temporary media URL to upload_video.
• To send video bytes directly (a client that holds the file rather than a URL), pass videoBase64 to upload_video instead of videoPathOrUrl. The server writes it to a temp file, uploads, then deletes it. Inline bytes are capped at UPLOAD_POST_MAX_INLINE_MB (default 100 MB) — for larger videos use a public URL.
• Always create the profile first (create_user) and connect socials in the Upload-Post dashboard before publishing.
• For scheduled posts, pass ISO 8601 dates with timezone, e.g. "2026-12-25T10:00:00Z" + "timezone": "Europe/Madrid".

Privacy & data handling

This server is a stateless proxy to the Upload-Post API. Per request, the only data it processes is the user's API key (or OAuth access token resolved to one) and the arguments of the tool call being executed. No user data is persisted by the MCP container itself.

• What we receive per request: the Authorization header, the MCP tool name + arguments, and any media URLs/paths the agent passes.
• What we forward: the tool arguments to the Upload-Post API on behalf of the authenticated user.
• What we store: nothing per-user. OAuth tokens are stored upstream in the Upload-Post backend, hashed (SHA-256), so a breach of token storage cannot impersonate users.
• What we log: HTTP method, path, status code, and an opaque request ID. No tool arguments, no API keys, no tokens.

Full Upload-Post privacy policy (data collection, retention, third-party sharing, contact, GDPR/CCPA): https://upload-post.com/privacy

To revoke a connector's access at any time, open Connected Apps in app.upload-post.com.

Security

• All traffic is TLS-terminated at the edge (HTTPS only).
• /mcp requires a valid Authorization header on every request; OAuth access tokens are short-lived (1 h access + 90 d refresh with rotation per RFC 6749 §10.4).
• The server validates the Origin header against an allow-list (claude.ai, claude.com, chatgpt.com, chat.openai.com, app.upload-post.com, localhost) to mitigate DNS-rebinding attacks from browser-based clients. Extend with OAUTH_EXTRA_ALLOWED_ORIGINS (comma-separated) when self-hosting behind a custom dashboard.
• If ChatGPT shows redirect_uri not on allow-list during OAuth, add the exact redirect_uri from the failing authorize request to the Upload-Post backend OAuth redirect allow-list. For ChatGPT clients this is typically on https://chatgpt.com/.../oauth/callback or https://chat.openai.com/.../oauth/callback.
• All tools declare MCP readOnlyHint/destructiveHint annotations so clients can surface confirmation prompts for destructive operations.

Report a security issue: info@upload-post.com (encrypted PGP available on request).

License

MIT © Upload-Post