HTTP Status Code

The HTTP 200 status code only indicates that the server successfully received and processed the request; it does not represent correct execution of business logic, as a large number of business errors can be wrapped inside a 200 response body.

When validating an API endpoint, 401 means the Key is wrong, has been revoked, or is missing the Bearer prefix; 402 means an account balance or billing issue; 403 means an environment or permission mismatch; 400/404 (for the model) means the Model ID has expired; and 429/5xx are the only two status codes worth retrying.

When encountering non-retryable status codes (such as 400, 401, 404), break directly to the next model, because retrying is pointless.

HTTP status codes that should be retried include: 429, 502, 503, 504, as well as network-layer failures such as connection resets and timeouts.

Among HTTP status codes, those starting with 2 indicate success (200 success, 201 created successfully, 204 success but no response content), those starting with 3 indicate redirection or caching (301 and 302 redirection, 304 caching), those starting with 4 indicate client errors (401 no authentication provided, 403 no permission, 422 parameter format incorrect, 429 requests too frequent), and those starting with 5 indicate internal server errors.

The bare error codes returned by traditional APIs (such as 404, 500) will trap an Agent in an ineffective retry loop, because an Agent lacks the contextual ability of a human developer to consult logs and documentation.

HTTP status code 200 indicates the page returns normally; 301/302 indicates a redirect, and overly long chains dilute authority; 404 indicates the page does not exist; 410 indicates the content has been permanently removed; 5xx indicates a server error.

An HTTP 200 status code means the server has accepted and started running the task, but it does not guarantee the processing result is correct; a status code other than 200 means the task did not start.

Once a response has started with a 200 status code, the status code can no longer be changed; therefore exceptions should be wrapped as explicit error events and sent to the frontend.

In model invocation scenarios, a 404 typically means the model ID does not exist or has been taken offline, and is a signal to try a different model.

HTTP 503 indicates the server is temporarily unable to handle the request, 500 indicates a backend logic anomaly, and 404 indicates that the requested resource does not exist.

接口自动化编排中，401表示认证失败、404表示资源不存在，AI可根据HTTP状态码智能诊断问题