{"name":"API Change Feed","description":"Machine-readable breaking changes, deprecations and security fixes for popular APIs and SDKs. Paid per call via x402 (USDC). No account or API key.","docs":{"llms_txt":"/llms.txt","openapi":"/openapi.json"},"free":["/v1/sources","/v1/preview"],"paid":{"/v1/changes":"$0.005","/v1/upgrade-check":"$0.01","/v1/digest":"$0.02"},"sandbox":"Same endpoints under /sandbox/v1, paid with test USDC on Base Sepolia; data delayed 30 days. For integration testing.","mcp":"/mcp","discovery":["/.well-known/x402","/.well-known/x402.json","/.well-known/agent.json"]}