BABYDOV Postcondition Verify — HTTP Response Assertion & Evidence

Choose this endpoint when an AI agent needs cryptographically auditable, tamper-evident proof that a live HTTP resource satisfies specific postconditions — such as before releasing a bounty, confirming a deployment went live, or validating a third-party API contract. It is superior to a simple HTTP fetch when you need a verifiable evidence record (SHA-256 + verification ID), combinatorial logic (all/any) over multiple assertions, or low-cost autonomous verification without standing up your own infrastructure. Prefer alternatives if you need to extract or transform the response body rather than just assert conditions on it.

• Target URL unreachable or DNS resolution failure — verification fails with network error
• Target URL returns unexpected status code — check fails, failed_check_count incremented
• Response body does not contain expected string — assertion fails
• SHA-256 hash mismatch — hash check fails
• Response latency exceeds max_latency_ms — latency check fails
• Max redirects exceeded — redirect check fails
• Malformed URL in queryParams.url — input validation error
• logic enum value not in ['all','any'] — schema validation error
• Missing required 'url' in queryParams — 400 bad request
• x402 payment not satisfied — 402 payment required before response