Cursor Model Provider Errors — 401, 429, Unable to Reach
With a custom Anthropic key, Cursor talks to the provider directly, so most failures are either the key/base-URL configuration or the provider's own response passed through. The pages below separate the two.
| Error | Meaning |
|---|---|
We're having trouble connecting to the model provider. This migh… | Cursor reports it cannot reach the model provider when the request dies before an HTTP response: wrong base URL, network path, or a provider outage. How to tell which one you have. |
Invalid API key | Cursor rejects an Anthropic key on verify when the key and the base URL do not belong together, or the override field still points at the default endpoint. The checklist that fixes it. |
Request failed with status code 401 | A 401 inside Cursor chat means the provider answered and rejected the credentials: key and base URL mismatched, key revoked, or the wrong header reaching the endpoint. The fix path. |
{"type":"error","error":{"type":"rate_limit_error","message":"Th… | With a custom Anthropic key, a 429 in Cursor is the key's own per-minute ceiling, not Cursor's plan limits. Why long chats trigger it and how to stop the loop. |
Cursor: Unable to Reach the Model Provider — Causes and Fixes
Cursor reports it cannot reach the model provider when the request dies before an HTTP response: wrong base URL, network path, or a provider outage. How to tell which one you have.
Cursor Invalid API Key (Anthropic) — Why Verify Fails
Cursor rejects an Anthropic key on verify when the key and the base URL do not belong together, or the override field still points at the default endpoint. The checklist that fixes it.
Cursor: Request Failed With Status Code 401 — Anthropic Key Fix
A 401 inside Cursor chat means the provider answered and rejected the credentials: key and base URL mismatched, key revoked, or the wrong header reaching the endpoint. The fix path.
Cursor Rate Limit / 429 With Your Own Anthropic Key
With a custom Anthropic key, a 429 in Cursor is the key's own per-minute ceiling, not Cursor's plan limits. Why long chats trigger it and how to stop the loop.