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Model Fingerprint Detection

Ask the model three “pick integers by instinct” questions, compare the number distribution against every official model in the fingerprint bank, and find out which model is really behind the endpoint.

Start a check

Takes about 30–90 s, longer for reasoning models. Just the endpoint, model and key.

Sampling requests are sent from the CCTest server. Your key is used only for this check and is never stored.

Stop at /v1; the path for the selected protocol is appended automatically.

Protocol
Parallel requestsSend all three samples at once: faster, but more likely to hit rate limits

01Send 3 test requests to the endpoint

Sent from CCTest servers; the key is discarded afterwards

02Compare against official model fingerprints

Every model picks “random” numbers differently

03Get a verdict with confidence

Swapped or not, closest model, and its family