# Substack Publication Scraper: Posts, Authors & Stats (`accountable_eel/substack-publication-lookup`) Actor Look up any Substack publication by handle or domain via Substack's own archive API. Get name, tagline, posting cadence, free-vs-paid mix, top keywords, and the last 10 posts with engagement counts, built for sponsor prospecting. No subscriber counts (Substack never exposes those). - **URL**: https://apify.com/accountable\_eel/substack-publication-lookup.md - **Developed by:** [Adrian Voss](https://apify.com/accountable_eel) (community) - **Categories:** Lead generation, Social media - **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 1 bookmarks - **User rating**: No ratings yet ## Pricing from $1.50 / 1,000 publication looked ups This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events. Since this Actor supports Apify Store discounts, the price gets lower the higher subscription plan you have. Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event ## What's an Apify Actor? An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes. In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours, and optionally produces a well-defined JSON output, datasets with results, or files in key-value store. In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server. Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md. ## How to integrate an Actor? If asked about integration, you help developers integrate Actors into their projects. You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready. Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run. For examples already wired to this Actor's own input schema, see the [API](#api) section below. Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`). # README ## Substack Publication Lookup Look up any [Substack](https://substack.com) publication by handle or domain against Substack's own archive API (`.substack.com/api/v1/archive`) — publication name and tagline, estimated posting cadence, free-vs-paid content mix, top recurring keywords from recent titles, and the last 10 posts with engagement counts. Built for sponsor prospecting and newsletter research, not a raw post-by-post scrape. ### Features - **Handle, subdomain, or custom-domain input.** Paste a bare handle (`astralcodexten`), a full `.substack.com` URL, or a custom domain the publication uses instead (`www.astralcodexten.com`) — all three resolve the same way. A custom domain that only routes its `www.` subdomain to Substack is retried automatically. - **Sponsor-ready summary, not a raw feed.** One row per publication: name, tagline, estimated posts/week, paid-content ratio, and top keywords — the shape a media buyer or sponsor-outreach tool actually needs, not 30 separate post rows to aggregate yourself. - **Recent posts with engagement.** The last 10 posts, each with its title, URL, publish date, audience gate (free/paid), like count, and comment count. - **Honest about its limits.** No subscriber counts — Substack does not expose those publicly, and this actor does not guess. Cadence and keyword topics are both computed over the sampled window only (up to 30 recent posts), not a lifetime average or a real topic model — see [FAQ](#faq). - **Pay only for hits.** Handles that don't resolve to an active Substack publication cost nothing — see [Pricing](#pricing). ### How to use Substack Publication Lookup 1. **In the Apify Console.** Open the actor page and click **Start** — the `publications` field is already pre-filled with a working example. Results land in the run's dataset as soon as each item is found. 2. **Via the API.** Call it directly with a POST request — no Console needed once you have an API token: ```bash curl "https://api.apify.com/v2/acts/accountable_eel~substack-publication-lookup/run-sync-get-dataset-items?token=" \ -X POST \ -H "Content-Type: application/json" \ -d '{"publications":["astralcodexten"]}' ``` 3. **On a schedule.** Save this actor as an Apify **Task** with the input you want, then add a **Schedule** (hourly, daily, weekly) so it runs on its own — no server of your own required. ### Input ```json { "publications": [ "astralcodexten" ] } ``` One per line. A Substack handle (e.g. stratechery), a full .substack.com URL, or a custom domain if the publication is still Substack-hosted (e.g. www.astralcodexten.com). Custom domains that only route their "www." subdomain to Substack are retried automatically. Accepted formats: astralcodexten, https://noahpinion.substack.com, www.astralcodexten.com. ```json { "publications": ["astralcodexten", "https://noahpinion.substack.com"], "testRun": false, "onlyFound": false, "columns": ["publicationName", "postingCadencePerWeek", "paidPostRatio", "topics", "recentPosts"], "maxConcurrency": 5, "proxyConfiguration": { "useApifyProxy": true } } ``` `publications` is a list of Substack handles, `.substack.com` URLs, or custom domains — one per line. Turn on `testRun` to process only the first 5 items before running the full list. `onlyFound` hides rows with no result (misses are always free). `includeKeywords` / `excludeKeywords` filter by keyword, and `maxResults` stops the run early. `columns` picks which fields appear in each row — all are included by default. ### Output One row per publication, for example: | query | found | status | publicationName | description | platformUrl | postCount | firstPostDate | lastPostDate | postingCadencePerWeek | paidPostRatio | topics | recentPosts | scrapedAt | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | astralcodexten.substack.com | true | OK | Astral Codex Ten | P(A|B) = \[P(A)\*P(B|A)]/P(B), all the rest is commentary. Click to read Astral Codex Ten, by Scott Alexander, a Substack publication. | https://astralcodexten.substack.com/ | 23 | 2026-07-30T01:07:16.450Z | 2026-08-28T17:32:14.561Z | 5.42 | 0.09 | \["book","open","review","thread","contest","finalist","debate","hidden"] | \[{"title":"Your Book Review: Thomas Urquhart’s Translation Of Rabelais","url":"https://www.astralcodexten.com/p/your-book-review-thomas-urquharts","publishedAt":"2026-08-28T17:32:14.561Z","audience":"everyone","reactionCount":161,"commentCount":61},{"title":"Hidden Open Thread 448.5","url":"https://www.astralcodexten.com/p/hidden-open-thread-4485","publishedAt":"2026-08-27T21:21:19.345Z","audience":"only\_paid","reactionCount":9,"commentCount":204},{"title":"Take The 2026 ACX Survey","url":"https://www.astralcodexten.com/p/take-the-2026-acx-survey","publishedAt":"2026-08-27T07:16:18.580Z","audience":"everyone","reactionCount":77,"commentCount":499},{"title":"Highlights From The Comments On The Substack Religion Debate","url":"https://www.astralcodexten.com/p/highlights-from-the-comments-on-the-491","publishedAt":"2026-08-25T16:03:47.167Z","audience":"everyone","reactionCount":134,"commentCount":412},{"title":"Re: Re: Re: Pritchard On Liberal Happiness","url":"https://www.astralcodexten.com/p/re-re-re-pritchard-on-liberal-happiness","publishedAt":"2026-08-24T23:54:20.847Z","audience":"everyone","reactionCount":419,"commentCount":455},{"title":"Open Thread 448","url":"https://www.astralcodexten.com/p/open-thread-448","publishedAt":"2026-08-24T02:48:38.910Z","audience":"everyone","reactionCount":69,"commentCount":446},{"title":"Your Book Review: A Residence Of 21 Years In The Sandwich Islands","url":"https://www.astralcodexten.com/p/your-book-review-a-residence-of-21","publishedAt":"2026-08-21T17:16:16.964Z","audience":"everyone","reactionCount":153,"commentCount":85},{"title":"College EA Meetups Everywhere: Call For Organizers","url":"https://www.astralcodexten.com/p/college-ea-meetups-everywhere-call","publishedAt":"2026-08-20T19:55:39.806Z","audience":"everyone","reactionCount":103,"commentCount":51},{"title":"Why I'm Staying Out Of The Substack Religion Debate","url":"https://www.astralcodexten.com/p/why-im-staying-out-of-the-substack","publishedAt":"2026-08-19T05:24:22.705Z","audience":"everyone","reactionCount":427,"commentCount":838},{"title":"Open Thread 447","url":"https://www.astralcodexten.com/p/open-thread-447","publishedAt":"2026-08-17T19:52:17.873Z","audience":"everyone","reactionCount":47,"commentCount":638}] | 2026-08-31T06:30:24.957Z | ```json { "query": "astralcodexten.substack.com", "found": true, "status": "OK", "publicationName": "Astral Codex Ten", "description": "P(A|B) = [P(A)*P(B|A)]/P(B), all the rest is commentary. Click to read Astral Codex Ten, by Scott Alexander, a Substack publication.", "platformUrl": "https://astralcodexten.substack.com/", "postCount": 30, "firstPostDate": "2026-08-05T12:00:00.000Z", "lastPostDate": "2026-08-24T08:46:48.970Z", "postingCadencePerWeek": 11.05, "paidPostRatio": 0.2, "topics": ["open", "thread", "review", "book", "links", "ai", "war", "meetup"], "recentPosts": [ { "title": "Open Thread 448", "url": "https://www.astralcodexten.com/p/open-thread-448", "publishedAt": "2026-08-24T02:48:38.910Z", "audience": "everyone", "reactionCount": 55, "commentCount": 412 } ], "scrapedAt": "2026-08-24T15:00:00.000Z" } ``` A row is only marked `found: true` — and only then billed — once the handle resolves to an active Substack publication with at least one post in its archive. A handle with no matching publication comes back `status: "NOT_FOUND"` — `found: false` and never charged. ### Use cases - Qualify a list of newsletter handles for sponsor outreach by posting cadence and free-vs-paid mix before pitching. - Pull recent post titles and top keywords to gauge whether a publication's beat still matches your brand or product. - Track a competitor's or a partner's newsletter cadence over time by re-running the same handle on a schedule. - Enrich a spreadsheet of newsletter handles or URLs with a one-row intelligence summary each, instead of opening every publication by hand. - Feed publication metadata into a media-planning or CRM tool via the API or MCP, no manual copy-paste required. ### Pricing $3 per 1,000 Substack publications, plus a $0.00005 start fee. Misses (`found:false`) are never charged. ### Use it from Clay, n8n, Make, or an AI agent This actor runs synchronously over plain HTTP — call it directly from a script, a workflow tool, or an AI agent, no Apify Console needed once you have an API token. ```bash curl "https://api.apify.com/v2/acts/accountable_eel~substack-publication-lookup/run-sync-get-dataset-items?token=" \ -X POST \ -H "Content-Type: application/json" \ -d '{"publications":["astralcodexten"]}' ``` **n8n.** Add an HTTP Request node: Method `POST`, URL `https://api.apify.com/v2/acts/accountable_eel~substack-publication-lookup/run-sync-get-dataset-items?token=`, Body Content Type `JSON`, JSON Body `{"publications":["astralcodexten"]}` (swap in an expression from an earlier node for a real value). **Clay.** Add an "HTTP API" column: Method `POST`, URL `https://api.apify.com/v2/acts/accountable_eel~substack-publication-lookup/run-sync-get-dataset-items?token=`, Body `{"publications":["{{Substack publication}}"]}`, mapping the row's Substack publication into the `publications` array. **MCP.** In Claude, Cursor, or any MCP client with the Apify MCP server, ask for "Substack Publication Lookup | Apify" — the agent will find and run this actor. ### FAQ **Does this return subscriber counts?** No. Substack does not expose subscriber counts publicly anywhere — not in the archive API, not on the publication's own page. Any actor claiming to return exact subscriber numbers is guessing or scraping something Substack never intended to be public. This actor reports post volume, cadence, and engagement counts (likes, comments) instead, since those ARE genuinely public. **What does "posting cadence" actually measure?** It's `(posts sampled / days between the oldest and newest sampled post) * 7`, computed over up to the last 30 posts only — not the publication's lifetime average. A publication that recently changed its schedule will show its current pace, not its historical one. **What are "topics"?** Simple word-frequency counting over the sampled posts' titles and subtitles, filtered for common stopwords. It is not a topic model or NLP classifier — think of it as "the words that keep showing up," a cheap and honest signal, not a guarantee of thematic accuracy. **Does it work with a custom domain?** Yes, if the publication is still Substack-hosted on that domain — the same archive endpoint works there. If a bare custom domain 404s, the actor automatically retries with a "www." prefix, since several Substack custom domains only route their www subdomain to Substack's infrastructure. If a publication has migrated entirely off Substack (its own site, not Substack-hosted), no fallback can recover it. **Why might a well-known publication show a stale `lastPostDate`?** A handful of publications that left Substack for their own platform keep a frozen, no-longer-updated archive on their old `.substack.com` subdomain — it still resolves and returns data, just not current data. Check `lastPostDate` against what you expect before relying on freshness. **Does it require a Substack API key or login?** No — the archive endpoint is a free, public, unauthenticated JSON API that Substack's own publication pages use to render their post lists, so no key or login is needed. # Actor input Schema ## `publications` (type: `array`): One per line. A Substack handle (e.g. stratechery), a full .substack.com URL, or a custom domain if the publication is still Substack-hosted (e.g. www.astralcodexten.com). Custom domains that only route their "www." subdomain to Substack are retried automatically. Accepted formats: astralcodexten, https://noahpinion.substack.com, www.astralcodexten.com. You're only charged for the ones we actually find — a miss costs nothing. ## `testRun` (type: `boolean`): Turn this on to test your input on a small sample before running the full list. Turn it off to process everything. ## `onlyFound` (type: `boolean`): Only keep rows where something was actually found. Misses are always free, whether or not you show them here. ## `includeKeywords` (type: `array`): Optional. Only keep results that mention at least one of these words (e.g. a job title, a city, a product name). Leave empty to keep everything. ## `excludeKeywords` (type: `array`): Optional. Drop any result that mentions one of these words. Leave empty to skip nothing. ## `maxResults` (type: `integer`): Optional. Stop the run once this many results have been found — useful for a quick, cheap sample. Leave blank for no limit. ## `columns` (type: `array`): Choose which pieces of information to include in each result row. All are included by default. ## `maxConcurrency` (type: `integer`): Parallel requests. Keep conservative — this target has no browser fallback, so getting blocked costs more than slow-and-steady. ## `proxyConfiguration` (type: `object`): Apify Proxy config. Residential recommended for anti-bot-sensitive targets. ## Actor input object example ```json { "publications": [ "astralcodexten" ], "testRun": false, "onlyFound": false, "includeKeywords": [], "excludeKeywords": [], "columns": [ "publicationName", "description", "platformUrl", "postCount", "firstPostDate", "lastPostDate", "postingCadencePerWeek", "paidPostRatio", "topics", "recentPosts" ], "maxConcurrency": 5, "proxyConfiguration": { "useApifyProxy": true } } ``` # Actor output Schema ## `results` (type: `string`): No description # API You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup. ## JavaScript example ```javascript import { ApifyClient } from 'apify-client'; // Initialize the ApifyClient with your Apify API token // Replace the '' with your token const client = new ApifyClient({ token: '', }); // Prepare Actor input const input = { "publications": [ "astralcodexten" ], "includeKeywords": [], "excludeKeywords": [] }; // Run the Actor and wait for it to finish const run = await client.actor("accountable_eel/substack-publication-lookup").call(input); // Fetch and print Actor results from the run's dataset (if any) console.log('Results from dataset'); console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`); const { items } = await client.dataset(run.defaultDatasetId).listItems(); items.forEach((item) => { console.dir(item); }); // 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs ``` ## Python example ```python from apify_client import ApifyClient # Initialize the ApifyClient with your Apify API token # Replace '' with your token. client = ApifyClient("") # Prepare the Actor input run_input = { "publications": ["astralcodexten"], "includeKeywords": [], "excludeKeywords": [], } # Run the Actor and wait for it to finish run = client.actor("accountable_eel/substack-publication-lookup").call(run_input=run_input) # Fetch and print Actor results from the run's dataset (if there are any) print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}") for item in client.dataset(run.default_dataset_id).iterate_items(): print(item) # 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start ``` ## CLI example ```bash echo '{ "publications": [ "astralcodexten" ], "includeKeywords": [], "excludeKeywords": [] }' | apify call accountable_eel/substack-publication-lookup --silent --output-dataset ``` ## MCP server setup ```json { "mcpServers": { "apify": { "type": "http", "url": "https://mcp.apify.com/?tools=fetch-actor-details,accountable_eel/substack-publication-lookup" } } } ``` The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer ` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations). ## OpenAPI specification Download the OpenAPI definition: https://api.apify.com/v2/actors/Rc0CO90aFDFSGjNmH/builds/hVGd1eEDp2AMBwGED/openapi.json