Flow Unified API

Errors

Structured JSON errors — 4xx for request/access problems, 5xx for retryable platform failures.

Errors are returned as structured JSON. Treat 4xx as request or access problems, and 5xx as retryable platform failures.

StatusMeaning
422Invalid request — malformed body, bad query parameters, or a body that fails the entity's unified schema validation.
401Missing, malformed, or revoked API key. Check the authorization header.
404Unknown accountId, or an entityType this account's platform does not expose.
429The backing system's rate limit was reached. Retry with exponential backoff.
5xxTemporary LinkToAny or platform issue. Safe to retry idempotent reads; retry writes with the same externalId — it doubles as the idempotency key.

SDK error classes

The Node.js SDK maps each status onto a typed error class. Retryable failures (429, 5xx, network) retry automatically with exponential backoff honouring Retry-After before anything throws.

Error classStatusMeaning
AuthenticationError401Missing, malformed, or revoked API key.
PermissionError403Key is valid but not scoped for this account or action.
NotFoundError404Unknown accountId, or an entityType this account's platform does not expose.
ValidationError400 / 422Request or write payload failed schema validation — see err.body.
RateLimitError429Raised only after automatic retries are exhausted.
ServerError5xxTemporary LinkToAny or platform issue. Safe to retry idempotent reads.
TimeoutError / ConnectionErrorThe request never completed — network failure or timeoutMs exceeded.

Every error carries status, code, body, and requestId — include requestId when escalating to support.

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