0n3
MCP servers · Mailchimp · connector · GPT action

Connect ChatGPT to Mailchimp

One line gives ChatGPT your Mailchimp account as tools: 12 endpoints, audiences, members, campaigns, 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 Mailchimp first

Three steps

  1. Create a free 0n3 account and connect Mailchimp. 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 audiences in Mailchimp".
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 Mailchimp

Audiences · View and manage audiences/lists2
List audiencesGET /lists
Get an audienceGET /lists/{listId}
Members · Add and manage subscribers4
Add a memberPOST /lists/{listId}/members
Update a memberPATCH /lists/{listId}/members/{subscriberHash}
List membersGET /lists/{listId}/members
Search membersGET /search-members
Campaigns · Create and send email campaigns4
List campaignsGET /campaigns
Create a campaignPOST /campaigns
Send a campaignPOST /campaigns/{campaignId}/actions/send
Get a campaign reportGET /reports/{campaignId}
Templates · View email templates1
List templatesGET /templates
More · Everything else this app exposes.1
List automationsGET /automations

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ChatGPT with other apps

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