JSON Change Detector (structural diff) ($0.002/call)

Detect exactly what changed between two API responses, configs, or state snapshots. POST {a, b} returns every added, removed, and changed path with old/new values, plus an equal flag. Watch an endpoint for drift, verify a migration did what it claimed, assert before/after state in tests — nested objects and arrays handled, no traversal code to write.

Paid endpoint: $0.002 per call via the x402 protocol (USDC on Base). An unpaid request returns 402 with payment requirements in the PAYMENT-REQUIRED response header; attach payment and retry.