Buffer API + MCP vs Postiz API + MCP

Buffer API + MCP

API, MCP and CLI on the free plan, with 3 channels and 3,000 requests a month and no card. 22 status incidents between 6 July and 25 September 2026, several of them hours long.

Postiz API + MCP

AGPL-3.0 and self-hostable with the API and MCP included, 34 platforms. Create-post capped at 90 requests an hour on every Cloud plan.

Buffer API + MCP

1. Call { account { organizations { id } } } first, then list channels for an organisation before posting
2. Include ... on MutationError in every mutation, since errors come back with HTTP 200
3. On 429, wait Retry-After plus a few seconds of jitter. The 429 itself doesn't cost quota
4. Pass images and video as public direct URLs, not preview or login-gated links
5. Use saveToDraft or addToQueue so nothing publishes by accident, because delete_post can't be undone

Postiz API + MCP

1. Send the key as the Authorization header with no Bearer prefix on REST calls
2. Batch several posts into one create request to stay under 90 an hour
3. Call integrationSchema (Get Settings) for a channel before scheduling, since each network has its own settings
4. Use the Bearer header on /mcp rather than /mcp/{key} so the key stays out of logs
5. Read output.errors on a failed schedule call and retry with the corrected fields