API reference

Errors and rate limits

Every failure in the Preflight API is a JSON body with a stable code, a message written for a person and, when a field is at fault, its name. The status says what kind of failure it is: 4xx for a request the API will not take as sent, 402 for the plan's allowance, 422 for a post a network would refuse, 424 for a refusal passed on from a network, 429 for a rate limit. Requests are limited per address and, for the costlier calls, per key.

Errors and limits

Failures return a stable code and a message meant to be read by a person.

{ "error": { "code": "invalid_request", "message": "targets[] is required.", "field": "targets" } }

400invalid_requestThe body did not validate; field says which

400no_slotsA queued post for a channel without a schedule

401unauthorizedMissing, expired or unrecognised key

402post_limit, upload_limit, file_too_large, channel_limit, ai_limit, ai_not_in_planThe plan's allowance

403forbiddenThe key lacks the scope for this call

404not_foundNo such post, file or account here

409account_not_connected, media_unusableA named account or file cannot be used

409already_started, targets_locked, in_flight, nothing_to_retryNot in the post's current state

409unsupported, not_published, account_disconnected, unsupported_connection, account_missingThe network or target does not allow this

409video_on_youtubeThe video already waits on YouTube; the file cannot change

413payload_too_large, file_too_largeA request body over 1 MB, or a file over the server's 2 GB

422validation_failedA network would refuse it; see issues

422ai_declinedThe assistant would not write this

429rate_limitedToo many requests; wait for Retry-After

424metrics_failed, comments_failed, comment_action_failed, update_failed, delete_failed, youtube_refused, playlist_refused, ai_failedThe network or the assistant refused; its message is passed on

503ai_unavailableThe assistant is not set up on this server

A 402 carries limit: { used, allowed } and the plan that would allow it in upgradeTo. Requests are limited to 600 a minute per address, with tighter limits on creating files (60), on AI (20), on account lookups such as boards and playlists (60), on creating webhooks (20) and on MCP (120). The tighter limits count per key.

Questions: info@preflight.social. The same API as a schema: openapi.json (OpenAPI 3.1).

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