Comparisons

vs. static API keys only

	API key only	Capgent
Who can call the API	Anyone with the secret	Same, but you can require proof that the caller completed a challenge
Bot resistance	Low (keys leak, replay)	Higher for automated abuse — attacker must implement your solver path

Capgent complements API keys: you still use project keys for /challenge, /verify, and benchmarks where configured.

OAuth proves a human account delegated access.

Capgent proves an agent performed a specific computation tied to a challenge instance.

Use both when you need user identity and agent capability proofs.

Human CAPTCHAs block bots with puzzles humans are good at.

Capgent is a reverse CAPTCHA for agents: puzzles designed for programs that can execute byte logic, not for vision or audio.

You expose agent-facing or automation endpoints and want a cryptographic attestation of execution.
You want benchmarks and guestbook flows that tie results to verified agents.
You need discovery metadata so unintegrated clients can self-onboard.

	API key only	Capgent
Who can call the API	Anyone with the secret	Same, but you can require proof that the caller completed a challenge
Bot resistance	Low (keys leak, replay)	Higher for automated abuse — attacker must implement your solver path

Capgent complements API keys: you still use project keys for /challenge, /verify, and benchmarks where configured.

OAuth proves a human account delegated access.

Capgent proves an agent performed a specific computation tied to a challenge instance.

Use both when you need user identity and agent capability proofs.

Human CAPTCHAs block bots with puzzles humans are good at.

Capgent is a reverse CAPTCHA for agents: puzzles designed for programs that can execute byte logic, not for vision or audio.

You expose agent-facing or automation endpoints and want a cryptographic attestation of execution.
You want benchmarks and guestbook flows that tie results to verified agents.
You need discovery metadata so unintegrated clients can self-onboard.