List all Mailchimp audiences/lists. Returns list IDs needed for campaign creation.

List available Mailchimp email templates.

List recent Mailchimp campaigns.

Get details of a specific campaign by ID.

Create a new Mailchimp email campaign. Returns the campaign ID for use with set_campaign_content and send_campaign.

Set the HTML/plain-text content for a campaign. Provide either html for custom content or template_id to use a Mailchimp template.

Get the current HTML and plain-text content of a campaign.

Send a test email for a campaign before sending to the full audience.

Send a campaign to its audience. This action is irreversible — the campaign will be sent immediately.

Schedule a campaign to send at a specific time in the future.

List members/subscribers in a Mailchimp audience. Use for syncing or auditing contacts.

Add a new subscriber or update an existing one in a Mailchimp audience. Uses email as the unique key (upsert). Will not change subscription status of existing members.

Add multiple subscribers to a Mailchimp audience in one call. Handles up to 500 members per batch. Will not overwrite existing members' subscription status.