0n3
MCP servers · Substack · MCP server

Connect Codex CLI to Substack

One line gives Codex CLI 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 Codex CLI's access alone any time.

Get the line for Codex CLIConnect 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 Codex CLI. OpenAI's terminal agent reads 0n3 over Streamable HTTP with a token from your environment.
  3. Ask Codex CLI: whoami. Then: "List posts in Substack".
Put the token in your environment
export ON3_TOKEN="<your 0n token>"

Add it to your shell profile so Codex finds it next time.

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

What Codex CLI 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

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Codex CLI with other apps

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