Eight social platforms.
Right inside
One install line. Twenty-one MCP tools. Your agent now publishes to eight social platforms — text, image, video, scheduled, replied, quoted — without you shipping a per-platform SDK. OAuth 2.1 with Dynamic Client Registration, so the agent registers itself.
ONE LINE TO INSTALL
$ npx -y @letmepost/mcp@latest # Add as an MCP server in Claude Desktop, Cursor, Claude Code, Windsurf. # Or use the hosted server at api.letmepost.dev/mcp with OAuth 2.1 — no API key in any file.
Auth, your agent registers itself.
oauth 2.1 + dynamic client registration (rfc 7591)
Agent posts to /oauth/register.
RFC 7591 endpoint. Returns a fresh client_id and client_secret scoped to the agent's metadata (name, redirect URIs, software statement).
Agent runs the standard OAuth 2.1 PKCE flow.
Authorization code with PKCE. User clicks "Allow letmepost access," gets redirected back, the agent exchanges the code for an access + refresh token.
Agent calls the MCP server with Authorization: Bearer ….
Every MCP tool call carries the bearer. Scope-checked server-side. Errors come back in the same envelope as the HTTP API.
Token refresh is automatic.
The MCP server returns a token.expiring event 5 minutes before refresh. The stdio binary handles the refresh exchange transparently.
Transport & safety.
streamable http · stateless · idempotent
Transport
Streamable HTTP on the hosted server. The npm binary @letmepost/mcp runs as stdio for desktop clients (Claude Desktop, Cursor, Windsurf).
Stateless & replay-safe
Every call carries its own bearer + idempotency key. Agents can fail over, restart, or hot-swap auth without server-side reconciliation.
Billing.
every tool call is one api call
A posts_create tool call counts as one post on your monthly quota. Same rate as
the HTTP API. The free tier (50 posts/mo) is enough to wire your agent end-to-end.
Full pricing →
Fine print, agents.
questions an agent-builder would ask
What does my agent need to know about MCP?
Nothing letmepost-specific. If your client speaks MCP, it can talk to us. Add the install line, restart the client, and the tools appear in the model's tool surface automatically.
API key vs OAuth, which should my agent use?
API key for local development and CI. OAuth 2.1 + DCR for production agents that should not embed a long-lived shared secret. Both work over the same MCP endpoints.
What happens if my agent retries a posts_create call?
If the same idempotency key was used, the cached response comes back (within 24h). No double-post. If a different idempotency key was used, you get an idempotency_conflict response (HTTP 409).
Can my agent self-host the MCP server?
Yes. The MCP server is part of the open-source Docker image. docker compose up runs it locally on port 4001. Same tool surface, your platform credentials.
What about audit logs?
Every tool call is logged with the agent's client_id (for OAuth) or last-4 of the API key. Visible in the dashboard. 30-day retention on Pro, 180 on Business.
Where do I report bugs in the MCP server?
Open an issue on the repo. Tag it mcp. We respond within 24h on weekdays during alpha.
PLUG YOUR AGENT IN.
One install line. Twenty-one tools. Eight platforms.
Agents-first issue tracker — file anything weird and it gets prioritised.