{"uid":"cap_iVOcsCEj1uuwQI1D3Smiq","slug":"polygon-pos-checkpoint-fetcher-57a39a2d","name":"Polygon PoS Checkpoint Fetcher","description":"Polygon PoS checkpoints from the Heimdall API: the latest K checkpoints (1 to 10) with their Bor block range, timestamp and proposer, plus the average spacing in blocks and seconds. Checkpoints are the Ethereum-anchored root commitments. State-sync logs are not included.","url":"https://api.chainmarket-api.workers.dev/api/crypto/polygon-pos-checkpoints?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"count":{"type":"string","description":"How many latest checkpoints, 1 to 10 (default 3)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"count":3,"source":"https://heimdall-api.polygon.technology/checkpoints/latest","checkedAt":"2026-10-23T09:36:01.084Z","checkpoints":[{"id":114911,"endBlock":96027301,"proposer":"0x203847fbc212987f83680e0682e45e930eb11b0e","timestamp":"2026-10-23T09:23:36.000Z","blockCount":1536,"borChainId":"137","startBlock":96025766},{"id":114910,"endBlock":96025765,"proposer":"0x02f70172f7f490653665c9bfac0666147c8af1f5","timestamp":"2026-10-23T08:43:56.000Z","blockCount":512,"borChainId":"137","startBlock":96025254}],"avgBlocksBetween":1024,"avgSecondsBetween":1600.5}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_qSQh5LoG_O2JgT2eJEba7","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the latest Polygon PoS (Heimdall) checkpoints including block ranges, proposers, timestamps, and inter-checkpoint timing statistics.","exampleAgentPrompt":"What are the last 5 Polygon PoS checkpoints — give me the block ranges, proposers, and how long on average between them?","exampleUseCases":[{"title":"Monitoring Polygon finality latency","prompt":"Check the last 5 Polygon PoS checkpoints and tell me how many seconds on average are passing between them — I want to track whether finality is getting faster or slower."},{"title":"Verifying checkpoint proposer activity","prompt":"Who proposed the most recent Polygon checkpoint and what block range did it cover? I need to verify a validator is active."},{"title":"Cross-chain bridge readiness check","prompt":"Pull the latest 3 Polygon PoS checkpoints for me — I need the end block and timestamp of the most recent one to confirm whether my transaction has been checkpointed to Ethereum yet."}],"resultDescription":"A JSON object containing the requested number of latest Polygon PoS checkpoints (default 3, max 10), each with checkpoint ID, start block, end block, proposer address, timestamp, block count, and Bor chain ID, plus aggregate statistics: average blocks between checkpoints and average seconds between checkpoints. Also includes the source URL and the time the data was fetched.","failureModes":["Invalid count parameter (outside 1–10 range) may return an error or default behavior","Upstream Heimdall API unavailability causing fetch failure","Stale data if the upstream Polygon Heimdall API is lagging","Network timeout from the Cloudflare Worker to the upstream source"],"whenToPreferThis":"Use this endpoint when you need real-time Polygon PoS checkpoint data sourced directly from Polygon's official Heimdall API, especially for finality monitoring, validator/proposer tracking, bridge readiness checks, or cross-chain state verification — without needing an API key or account. Prefer it over raw RPC calls when you want pre-parsed, structured checkpoint metadata with timing statistics in a single pay-per-call request.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-24T12:30:03.282Z","isFirstParty":false,"canonicalSlug":"polygon-pos-checkpoint-fetcher-57a39a2d"}