What is the Mailchimp Marketing API base URL?

The Mailchimp Marketing API base URL is https://{server}.api.mailchimp.com/3.0

Mailchimp Marketing API — Base URL, Auth & Endpoints

The Mailchimp Marketing API provides full programmatic control over your email marketing. Manage subscriber lists (audiences) and tags, create and send campaigns, build automation journeys, run A/B tests, pull campaign reports (opens, clicks, revenue), sync e-commerce purchase data, and manage templates. The API follows RESTful conventions with OAuth 2.0 for multi-account apps or API keys for single-account integrations.

Quick Reference

Base URL https://{server}.api.mailchimp.com/3.0 Auth type Basic Auth Auth header Authorization: Basic base64(anystring:YOUR_API_KEY) Rate limit 10 concurrent connections · No per-minute limit Pricing Free tier available Free quota 1,000 email sends/mo Documentation https://mailchimp.com/developer/marketing/api/ Endpoint status Unreachable — No response — server may be down or blocking automated probes (checked Mar 29, 2026) Builder score C 59% builder-friendly

Pricing

Latency

Depth

Authentication

Use HTTP Basic Auth with any string as username and your API key as password. Your server prefix (e.g., us1) is in the API key and determines your base URL.

Authorization: Basic base64(anystring:YOUR_API_KEY)

Pricing

Model freemium Starting price Free tier available Free quota 1,000 email sends/mo

Plan	Price/mo	Included
Free	Free	500 contacts, 1k sends/mo
Essentials	$13	500 contacts, 5k sends/mo
Standard	$20	Automation, A/B testing
Premium	$350	150k contacts, phone support

Free: 500 contacts, 1k sends/mo. Essentials: $13/mo (500 contacts). Standard: $20/mo. Premium: $350/mo (150k contacts).

Key Endpoints

Method	Path	Description
GET	`/lists`	List all audiences (subscriber lists)
POST	`/lists/{list_id}/members`	Add a subscriber to an audience
GET	`/campaigns`	List email campaigns with status filter
POST	`/campaigns`	Create a new email campaign
POST	`/campaigns/{campaign_id}/actions/send`	Send a campaign to its audience
GET	`/reports/{campaign_id}`	Get campaign performance report

Sample Request

curl "https://us1.api.mailchimp.com/3.0/lists" \
  -u "anystring:$MAILCHIMP_API_KEY"

Sample Response

{
  "lists": [{
    "id": "abc1234def",
    "name": "Main Subscribers",
    "stats": {
      "member_count": 4821,
      "avg_open_rate": 0.28,
      "avg_click_rate": 0.045
    },
    "date_created": "2022-01-15T10:00:00+00:00"
  }],
  "total_items": 3
}