Letmepost MCP server

letmepost.dev

An open-source social media publishing API that fails loudly.

One POST /v1/posts across every platform. Stable error codes, the rule that failed, the raw platform body, and a remediation — on every failure. Never an empty { body: {} }. No per-profile tax.

An alternative to: Ayrshare, Postiz, Buffer, Hootsuite, Hypefury.

Website · Docs · Quickstart · Dashboard · API Reference

Supports: Bluesky · LinkedIn · X · Threads · Instagram · Facebook · Pinterest · YouTube

The four guarantees on every request

1. Preflight, not postflight. Character counts, media formats, URN patterns, audit states, OAuth scope mismatches, YouTube quota — all validated locally before the upstream call.
2. Transparent errors. Stable letmepost code + the specific rule that failed + the raw platform body + a remediation hint. Always.
3. Pinned platform versions. We pin the header, track deprecations, upgrade internally. Your workflow doesn't break at 2 a.m. when LinkedIn sunsets v202412.
4. Idempotency by default. Every write accepts an Idempotency-Key. Retries are safe — no double-posting loops when a worker restarts mid-publish.

What it looks like

Request:

curl -X POST https://api.letmepost.dev/v1/posts \
  -H "Authorization: Bearer lmp_live_…" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
    "targets": [{ "accountId": "acc_…" }],
    "text": "Shipping letmepost.dev"
  }'

Failure:

{
  "error": {
    "code": "preflight_failed",
    "rule": "bluesky.text.max_graphemes",
    "platform": "bluesky",
    "platformVersion": "atproto-2026-04",
    "message": "Post text is 312 graphemes; Bluesky allows at most 300.",
    "remediation": "Shorten the post to 300 graphemes or fewer.",
    "docUrl": "https://docs.letmepost.dev/errors/preflight_failed",
    "ruleUrl": "https://docs.letmepost.dev/preflight/bluesky-text-max_graphemes",
    "requestId": "req_01HY6X4AWBJM2K9F2PTQMRD9JQ"
  }
}

Same shape across every platform. Same shape on every error class — preflightfailed, platformauthfailed, platformrejected, platformunavailable, ratelimited. The dashboard renders these directly. Your error handler doesn't need a per-platform branch.

Why this exists

Four things developers hit every week with incumbent social-media APIs:

Shortened. The full README is on GitHub.