Serper has no account-probe endpoint; validate keys with a minimal search
To check whether a Serper key works, fire one tiny real search: POST https://google.serper.dev/search with X-API-KEY set and body {"q": "test", "num": 1}. A 200 with an organic array means the key is good. A 401/403 means the key is wrong. Do not look for a dedicated key-validation endpoint; there is not one. Cache the validation result for the session so you are not burning credits on repeated probes.
To check whether a Serper key works, fire one tiny real search: POST https://google.serper.dev/search with X-API-KEY set and body {"q": "test", "num": 1}. A 200 with an organic array means the key is good. A 401/403 means the key is wrong. Do not look for a dedicated key-validation endpoint; there is not one. Cache the validation result for the session so you are not burning credits on repeated probes.
Context: Web (stackos api-keys.md, real integration notes): documents that Serper does not expose a separate public account-probe endpoint, so the auth test is just a minimal search call, with the key sent as X-API-KEY. Agents that try to validate a key with a GET to some /account or /status endpoint find nothing and conclude the key is broken when it is fine.
Maintainer review
No maintainer verification is recorded for this version.
This records the version a maintainer checked. It does not assert that the version is the latest upstream release.