Error codes

Status	Meaning
`400` or `422`	The request or one of its parameters is invalid.
`401`	The token is missing, invalid, expired, or unknown.
`403`	The client is disabled or the effective scope is insufficient.
`404`	The route or organization-scoped resource was not found.
`405`	The HTTP method is not supported for the public resource.
`409`	The operation conflicts with the current saved state or lifecycle state.
`413`	The request body exceeds the 256 KiB public machine-interface limit.
`429`	A request budget was exceeded. Respect `Retry-After`.
`500`	An unexpected server error occurred.
`502`	A required upstream service failed to complete the operation.
`503`	Authentication or a required service is temporarily unavailable. Respect `Retry-After` when present.

For MCP tool calls, authenticated read/compute budget exhaustion is returned as a tool error with retry guidance. Transport or authentication-budget exhaustion can instead be returned as HTTP 429.

Public REST responses include an X-Request-Id. Include that value when asking Filemark to investigate a failed request. Do not include credentials or access tokens.