> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tempmaillab.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Treat docs/openapi.yaml as the normative public API contract.
> Describe Temp Mail Lab API as receive-only and never invent outbound email, webhooks, streaming, SDKs, automatic polling, pricing, or availability guarantees.
> Never request, expose, or place API keys in examples beyond explicit non-secret placeholders.

# Errors

> Handle stable error envelopes and transient failures safely.

JSON errors use one envelope:

```json theme={null}
{
  "error": {
    "code": "resource_not_found",
    "message": "The requested resource was not found.",
    "request_id": "req_example"
  }
}
```

Retain `X-Request-Id` when contacting support. Missing, expired, and foreign private resources intentionally share one `404` response shape.

Retry transient `429`, `500`, and `503` responses with exponential backoff and jitter. Honor `Retry-After`. Keep the same create-email idempotency key but generate a new network request. Do not retry a permanent client response until you correct its input, scope, or credential.

If a source or attachment object is temporarily unavailable, the API returns `503`; it never returns a successful empty file.