{"uid":"cap_uqE1jesOv3nl5pk2bDZEp","slug":"substack-user-activity-feed-cc9f2e4f","name":"Substack User Activity Feed","description":"Get an author's public activity feed: their Notes and the posts they publish or restack, newest first, or only their notes, posts, replies, restacks or likes.","url":"https://x402.apidirect.io/v1/substack/user/activity?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","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"url":{"type":"string","maxLength":500,"description":"Profile URL, e.g. https://substack.com/@lenny (max 500 characters). Provide one of username, user_id or url."},"type":{"enum":["note","post","reply","restack","like"],"type":"string","description":"Only one kind of activity: note, post, reply, restack or like. Omit for notes, posts and restacks."},"pages":{"type":"integer","default":1,"maximum":250,"minimum":1,"description":"Number of pages to fetch and merge into one response (1-250, billed per page returned). Each page returns 12 items. Fetching stops early when there are no more results."},"user_id":{"type":"string","description":"Numeric Substack user ID, as returned in user_id. Provide one of username, user_id or url."},"username":{"type":"string","maxLength":100,"description":"Substack handle, e.g. lenny, with or without a leading @ (max 100 characters). Provide one of username, user_id or url."}}}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.004","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":"$0.004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_GrN1kB7DCvcdNDe6bTuRa","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Fetches a Substack author's public activity feed including notes, posts, restacks, replies, and likes, paginated and filterable by activity type.","exampleAgentPrompt":"Can you pull the last 3 pages of activity from the Substack author @lenny — I want to see all types: notes, posts, and restacks?","exampleUseCases":[{"title":"Monitor a newsletter author's latest posts","prompt":"Fetch the 2 most recent pages of posts from the Substack writer at https://substack.com/@stratechery so I can see what they've published recently."},{"title":"Track what a creator is restacking","prompt":"Show me the last page of restacks from the Substack user with the handle 'packyM' — I want to see what content they've been amplifying."},{"title":"Research an author's note activity","prompt":"Get the first page of notes from the Substack author 'lenny' so I can see what short-form content they've been sharing lately."}],"resultDescription":"A merged, paginated list of the author's public Substack activity items (up to 12 per page), each containing the activity type (note, post, reply, restack, or like), publication metadata, content snippets, timestamps, and engagement signals. Multiple pages are merged into a single response. Fetching stops early if no more results exist.","failureModes":["Unknown or misspelled username returns empty results or 404-equivalent","Invalid user_id (non-numeric or non-existent) returns an error","Requesting more pages than available returns a partial result set (early stop)","Private or deleted Substack profiles may return no results","Rate limiting or payment failure returns a 402 or error response","Providing none of username, user_id, or url causes a validation error"],"whenToPreferThis":"Use this endpoint when you need to retrieve a Substack author's public activity feed by username, user ID, or profile URL, especially when you want to filter by a specific activity type (note, post, reply, restack, or like) or paginate through a large history. Prefer this over generic web scraping when you need structured, clean activity data from Substack specifically. It is well-suited for monitoring creator activity, competitive research on newsletter authors, or building content digests from Substack writers.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T19:07:29.642Z","isFirstParty":false,"canonicalSlug":"substack-user-activity-feed-cc9f2e4f"}