Errors

Successful responses return the resource (or a { "data", "next_cursor" } page) verbatim. Errors use a single envelope:

{
  "error": {
    "code": "insufficient_scope",
    "message": "The API key does not grant leads:read.",
    "details": null
  }
}

code — a stable, machine-readable snake_case string. Branch on this, not the message.
message — a human-readable description; may change.
details — optional structured context, present only for some errors.

Status codes

Status	Meaning
`200`	OK
`201`	Created (a new lead from push, or a consultation from book)
`400`	Malformed request (bad JSON, invalid body)
`401`	Missing or invalid API key
`403`	Key disabled, or missing the required scope
`404`	No such resource (or it belongs to another firm)
`413`	Request body too large
`429`	Rate limit exceeded
`500`	Unexpected server error
`503`	The API is temporarily unavailable / not configured

`code`	Status	When
`missing_key`	401	No `Authorization` header
`invalid_key`	401	Key doesn't match an active key
`key_disabled`	403	Key has been disabled
`insufficient_scope`	403	Key lacks the required scope
`not_found`	404	Resource doesn't exist for this firm
`rate_limited`	429	Too many requests for this key
`internal_error`	500	Unexpected failure
`unavailable`	503	API not configured / temporarily down

A cross-firm id reads as 404 not_found, never 403 — the API doesn't reveal whether a resource exists in another firm.