0n3
MCP servers · Substack · connector · GPT action

Connect ChatGPT to Substack

One line gives ChatGPT your Substack account as tools: 3 endpoints, read posts, search posts, called with your own connection. No key in the prompt, a receipt for every call, revoke ChatGPT's access alone any time.

Get the line for ChatGPTConnect Substack first

Three steps

  1. Create a free 0n3 account and connect Substack. Paste a key or sign in; it lands in your vault, encrypted.
  2. Install 0n3 into ChatGPT. A custom connector in Developer mode, or an Action on a custom GPT from the OpenAPI spec.
  3. Ask ChatGPT: whoami. Then: "List posts in Substack".
Custom connector (needs Developer mode)
  1. Settings → Connectors (or Apps) → Advanced → Developer mode on
  2. Create → name 0n3 · MCP server URL https://0n3.app/mcp · Authentication: OAuth
  3. Finish the sign-in with your 0n account
  4. Enable the connector in a chat and ask: "whoami"

ChatGPT connectors cannot send a static header, so 0n3 signs you in through its OAuth door (dynamic client registration is on).

The line above carries a placeholder; 0n3.app/install mints a real key named for ChatGPT and fills it in.

What ChatGPT can then do in Substack

Read posts · List a publication's posts (archive) and fetch a single post by slug2
List postsGET /archive
Get a postGET /posts/{slug}
Search posts · Search posts within a publication1
Search postsGET /post/search

Substack in other AI clients

Claude Code + SubstackMCP server + skillClaude (desktop & claude.ai) + SubstackconnectorCodex CLI + SubstackMCP serverGemini CLI + SubstackMCP serverCursor + SubstackMCP serverVS Code (Copilot) + SubstackMCP serverWindsurf + SubstackMCP server

ChatGPT with other apps

Hostinger363 endpointsTelegram132 endpointsPipedrive95 endpointsResend67 endpointsSquare57 endpointsLinkedIn50 endpointsSlack45 endpointsFigma32 endpointsCloudConvert32 endpointseBay25 endpointsQuickBooks21 endpointsCloudflare21 endpoints