letmepost

Letmepost is an open-source HTTP API for publishing to social media. A single POST /v1/posts reaches Bluesky, LinkedIn, X, Instagram, Facebook, Threads, Pinterest, and TikTok, instead of wiring up a separate integration, OAuth flow, and error format for each one. The difference shows up when something breaks. Most social APIs fail silently: a post returns 200 and never appears, tokens rot after 60 days with no warning, and a platform version sunset quietly kills your automation overnight. letmepost fails loudly: Preflight validation: character counts, media rules, and OAuth scopes are checked locally before the call, so you catch problems before they ship. Transparent errors: every failure returns a stable code, the exact rule that broke, the raw platform response, and how to fix it. Pinned platform versions: we track upstream deprecations and upgrade internally, so your workflow doesn't break at 2 a.m. Idempotency keys : retries never double-post. Apache-2.0 and self-hostable; the hosted version runs the exact same code, with flat usage-based pricing (no per-profile tax). The machine-readable errors also make it a clean primitive for AI agents that need to post and correct their own mistakes.