{"uid":"cap_Hsp3BHWJNldmMcsRQbqlL","slug":"changelog-state-api-langchain-change-history-4f311a94","name":"Changelog State API – LangChain Change History","description":"Detected changelog update history for one tracked vendor.","url":"https://changelog-state-api.replit.app/api/monitors/langchain/changes","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"pathParams":{"type":"object","required":["slug"],"properties":{"slug":{"type":"string","pattern":"^[a-z0-9][a-z0-9-]*$","maxLength":64,"minLength":1,"description":"Vendor slug, lowercase alphanumeric with dashes."}}},"queryParams":{"type":"object","properties":{"type":{"enum":["new_release","version_changed","date_changed","title_changed","breaking_signal"],"type":"string","description":"Restrict to a single change type."},"limit":{"type":"integer","default":50,"maximum":200,"minimum":1,"description":"Maximum number of change rows to return."},"since":{"type":"string","format":"date-time","description":"Only return changes detected at or after this instant."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"enum":["json"],"type":"string"},"example":{"type":"object"}},"description":"Detected changelog update history (paid)"}},"description":"Call shape for GET /api/monitors/{slug}/changes."},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_QXG8JlpHZWldTSJ7TWXMm","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns detected changelog update history (new releases, version changes, breaking signals, etc.) for the LangChain vendor.","exampleAgentPrompt":"Show me all detected changelog changes for LangChain since last Monday, filtering to only new_release events, up to 100 results.","exampleUseCases":[{"title":"Breaking change alert for LangChain","prompt":"Have there been any breaking changes detected in LangChain's changelog in the past 30 days? Show me up to 50 results."},{"title":"Track LangChain releases for dependency updates","prompt":"List all new_release events detected for LangChain since January 1st, 2025 — I need to know when to update our dependency."},{"title":"Daily changelog diff for LangChain","prompt":"Pull me today's changelog update history for LangChain — anything detected since midnight UTC, all change types, up to 20 entries."}],"resultDescription":"A JSON array of detected changelog change records for LangChain, each including the change type (e.g. new_release, version_changed, breaking_signal), detection timestamp, and relevant metadata about what changed. Supports filtering by change type and time window.","failureModes":["Invalid slug format returns 400 (must be lowercase alphanumeric with dashes)","Untracked vendor slug returns 404 or empty results","since timestamp in wrong format (not ISO 8601) returns 400","limit exceeding 200 returns 400 validation error","Insufficient payment or failed x402 payment returns 402"],"whenToPreferThis":"Use this endpoint when you need a history of detected changelog mutations for LangChain specifically — including breaking signals, version bumps, and release events — with time-range and type filtering. Prefer this over the 'structured recent releases' sibling endpoint when you need raw change detection events rather than curated release summaries, or when you want to audit changelog mutations over time.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T06:43:45.657Z","isFirstParty":false}