Mailchimp
Connect Mailchimp to manage audiences, members, segments, and tags, and run campaigns, automations, and reports.
You end up with a single Mailchimp API key, ending in a data-centre suffix like -us21, that you paste into PopMCP's "API key" field.
- Setup time
- 3 min
- Auth
- API credentials
- API base URL
- https://<dc>.api.mailchimp.com/3.0
- Rate limits
- Mailchimp allows 10 simultaneous connections per API key and times out any single call after 120 seconds. Going over returns 429, and bulk work should use the batch endpoint.
Before you begin
- A Mailchimp account on any plan, including Free.
- Owner or Admin user level. Manager and below cannot open the API keys page.
- Somewhere safe to store the key, because Mailchimp shows it in full only once.
Get your credentials
Open the API keys page
Click your profile icon in the bottom-left corner and choose Profile, then open the Extras drop-down and pick API keys. The direct link is admin.mailchimp.com/account/api/, which redirects to your data centre.
API keys
Keys let other applications read and write your Mailchimp data.
| API key name | API key | Created | Status |
|---|---|---|---|
| Website formCreated by Dana R. | a1b2************-us21 | Jan 12, 2026 | Active |
| Old CRM syncCreated by Dana R. | 9f8e************-us21 | Mar 4, 2026 | Disabled |
Existing keys show their name and first four characters only.
Create a key and name it
Click Create A Key, type a name you will recognise later such as PopMCP, and click Generate Key.
Create API key
Name this key so you can find it later.
Mailchimp keys have no scopes, so the name is the only way to tell them apart.
Copy the key before you close the dialog
Click Copy Key to Clipboard, store the key somewhere safe, then click Done. Keep the trailing -us21 style suffix on the end.
API keys
The suffix after the hyphen names the data centre PopMCP will call.
Paste the key into PopMCP
Open the Mailchimp connector in PopMCP, paste the whole key including the suffix into API key, and save.
Connect in PopMCP
Open your workspace, choose Mailchimp in the marketplace, and fill in the connect dialog:
| Field | What to enter |
|---|---|
| API keysecret | Mailchimp → Account & billing → Extras → API keys → Create A Key. Copy the key (it ends with your datacenter, e.g. -us21). Stored encrypted.Encrypted with AES-256-GCM on save and never shown again. |
PopMCP verifies the credential against Mailchimp immediately. On success the connection flips to Verified and its MCP tools are provisioned.
Verify it worked
The Mailchimp connector in PopMCP flips to Connected and the tool list loads. Asking for your audiences returns your real list names and subscriber counts.
Troubleshooting
401 API Key Invalid
Why: The key was disabled or deleted in Mailchimp, or the user who owned it was removed from the account.
Fix: Open Profile → Extras → API keys, create a fresh key, and paste the new value into PopMCP.
Calls hit the wrong account, or 404 on every endpoint
Why: The data-centre suffix was trimmed when copying, so requests go to the wrong host.
Fix: Paste the key exactly as Mailchimp gave it, including the trailing hyphen and data centre such as -us21.
429 Too Many Requests
Why: Mailchimp allows only 10 simultaneous connections per key, shared with every other integration and the Mailchimp web app.
Fix: Retry after a moment, and give PopMCP a dedicated key so other tools do not eat the connection budget.
The API keys page is missing from the Extras menu
Why: Your Mailchimp user level is below Admin.
Fix: Ask the account Owner or an Admin to create the key, or to raise your user level in Account & billing → Settings → Users.
The key stopped working after a staff change
Why: Mailchimp keys belong to the user who created them, and removing that user disables their keys.
Fix: Have a current Owner or Admin generate a replacement key and paste it into PopMCP.