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newsletterapi

Private beta · access by invite

The newsletter API for your Substack

newsletterapi is the newsletter API for Substack writers. Paste your publication URL and get your posts and full archive as a REST API, an MCP server your AI agents can use, automatic backups and growth stats. It is read-only: no passwords, no scraping. Now in private beta, with access by email invite.

Which best describes you?

# Your whole archive, as JSON

GET /v1/publications/yourname/posts?q=pricing

{
  "data": [{
    "title": "Why I raised my price",
    "slug": "why-i-raised-my-price",
    "published_at": "2026-09-14",
    "audience": "everyone",
    "markdown": "When I started...",
    "url": "https://yourname.substack.com/p/..."
  }],
  "next_cursor": "c_9f2"
}

Illustrative response. The API is in private beta.

How it works

Connected in about five minutes

Read-only from start to finish. We never post or change anything.

  • Step 1

    Paste your Substack URL

    yourname.substack.com or your custom domain. No password, no browser extension.

  • Step 2

    We read your feed and export

    Your public RSS feed for new posts, and the export you upload for the full archive and stats.

  • Step 3

    Use it from code or your agent

    A REST API, an MCP server for Claude and ChatGPT, and automatic backups. Read-only.

  • ✓ Read-only
  • ✓ No passwords
  • ✓ No scraping
  • ✓ Your data is yours
  • ✓ Delete anytime

Substack API

Everything in your Substack, one API

Posts, archive search, backups, embeds and stats, from one read-only key. See all APIs.

MCP for your AI agent

Can Claude or ChatGPT read my Substack?

That is what our MCP server is for. Connect it once and your assistant can search your whole archive, quote your past posts and look at your growth numbers, so it drafts in your voice instead of guessing. It only reads; you still publish on Substack yourself.

See the MCP server plan or the Posts & Archive API it is built on.

Explore the MCP tools

You, in Claude

“What have I already written about burnout? Give me the three most relevant posts.”

# Claude calls a newsletterapi tool

{
  "tool": "search_archive",
  "input": "{ q, limit? }"
}

Illustrative example. The MCP server is in private beta.

Why not just use a library, the official MCP or RSS?

Each option works for something. Here is what each one gives you, and the catch, as of October 2026.

Ways to get your Substack data into code or an AI agent, compared
OptionWhat you getThe catch
DIY libraries and scrapersOpen-source clients that log in with your session cookie or password and call unofficial endpoints.Substack's Terms of Use (updated October 6, 2026) forbid crawling or scraping and letting anyone else log in as you. They also break: users report captcha errors at login and “Too Many Requests”.
Substack's official MCPRead-only access for AI assistants to dashboard metrics, traffic data and publication settings.You must be an admin of a Bestseller publication, and it cannot read Notes or profile data (Substack help centre).
RSS feedA free, public feed of new posts at /feed. Polling it is fine.Recent posts only: when we checked two public feeds on 2026-10-21, each returned its 20 latest posts. No archive search and no stats.
newsletterapi (planned)Your full archive as an API and MCP, backups and stats, for any Substack writer.Not built yet: it is in private preview, and we build the most-requested parts first. Read-only by design.

From the blog

All posts →

Questions people ask

Is this an official Substack API?
No. newsletterapi is an independent product, not affiliated with or endorsed by Substack. Substack's own MCP server is read-only and limited to Bestseller publication admins as of October 2026. We are building for every writer.
Can I use it today?
We are in private beta and onboarding by invite. Enter your email, pick the API you want, and we will email you an access link as we open each API, most-requested first.
Do you need my Substack password or login?
No. We never ask for your password or session cookie. We read your public RSS feed and the export file you download from Substack yourself and upload to us.
Can my AI agent publish posts through it?
No. It is read-only by design: agents can search and quote your archive and read your stats, and you publish on Substack yourself. See the MCP server plan for the planned tools.
What will it cost?
A free tier is planned, with paid plans from about $9 a month. Beta members lock in a discount. See planned pricing.

Get your Substack as an API

Enter your email and we will send your access invite. Beta members lock in a discount on launch pricing.