Campaign Monitor API

Name: Campaign Monitor API API
Brand: Campaign Monitor API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentMarketingEmail Marketingbasic, oauth272 EndpointsREST

For Agents

Manage email-marketing clients, lists, subscribers, campaigns, segments, templates, journeys, and transactional sends through a multi-tenant agency-friendly API.

Quickstart

Get started with Campaign Monitor API in minutes using your preferred integration method.

# Add to your MCP client config (Claude Desktop, Cursor, Windsurf)
{
  "jentic": {
    "url": "https://api.jentic.com/mcp",
    "auth": "oauth"
  }
}

# Then ask your agent:
"send an email campaign"

# → Jentic returns the GET /events tool with parameter schema, agent executes.

Capabilities

What an agent can do with Campaign Monitor API API.

Create and send draft email campaigns from /campaigns/{clientid}.json and /campaigns/{campaignid}/send.json

Manage subscriber lists, segments, and webhooks per client across an agency portfolio

Retrieve recipient activity and bounce reports for sent campaigns via /campaigns/{campaignid}/recipients.json and /bounces.json

Onboard new client workspaces with primary contacts and billing details via /clients.json and /primarycontact.json

GET STARTED

Start building with Campaign Monitor API API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI document for Campaign Monitor API, keeping it validated and agent-ready.

Jentic publishes the only available OpenAPI specification for Campaign Monitor API, keeping it validated and agent-ready. The Campaign Monitor REST API manages email-marketing accounts, client workspaces, subscriber lists, campaigns, segments, templates, transactional sends, journeys, and webhooks. Seventy-two endpoints cover the full lifecycle from creating a draft campaign through sending, retrieving recipient bounces, and exporting reporting data, with multi-client support that suits agencies running campaigns on behalf of multiple brands.

Use Cases

Patterns agents use Campaign Monitor API API for, with concrete tasks.

★ Agency Multi-Client Campaign Management

Marketing agencies running campaigns on behalf of many brands need a single API surface to create client workspaces, manage their lists, and dispatch campaigns. Campaign Monitor's client-scoped routes (/clients.json, /clients/{clientid}/lists.json, /campaigns/{clientid}.json) keep each brand's data isolated while letting the agency operate centrally.

Call POST /clients.json to onboard 'Acme Corp', create a list under that client via the Lists endpoints, then POST /campaigns/{clientid}.json to draft a launch announcement.

Automated Campaign Send and Reporting

Marketing-ops teams want to schedule a campaign, broadcast it, and feed bounce and engagement data back into a CRM. The Campaign Monitor API exposes /campaigns/{campaignid}/send.json for dispatch and /campaigns/{campaignid}/recipients.json plus /bounces.json for downstream reporting in a single integration.

POST /campaigns/{campaignid}/send.json to dispatch a campaign, then poll /campaigns/{campaignid}/bounces.json hourly and write each bounce to the CRM contact record.

Subscriber Hygiene and Compliance

Compliance workflows need to suppress unsubscribed or complained addresses across all of a client's lists. /clients/{clientid}/suppress.json adds addresses to the client-wide suppression list and /unsuppress.json reverses the action when a user re-opts in, helping keep deliverability scores high.

POST /clients/{clientid}/suppress.json with the email address from a complaint webhook to block future sends to that address.

AI Agent Email Workflows via Jentic

Through Jentic, an agent searches for 'send an email campaign', loads the input schema for /campaigns/{campaignid}/send.json, and executes the dispatch without managing Basic Auth or OAuth tokens directly. Jentic's vault stores the API key or OAuth token so it never enters the agent's prompt context.

Use the Jentic SDK to search 'send an email campaign', load the /campaigns/{campaignid}/send.json operation, and execute it with the campaign ID returned from a draft creation step.

Key Endpoints

72 endpoints — jentic publishes the only available openapi specification for campaign monitor api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

POST

/clients.json

Create a client workspace

POST

/campaigns/{clientid}.json

Create a draft campaign for a client

POST

/campaigns/{campaignid}/send.json

Send a draft campaign

GET

/campaigns/{campaignid}/recipients.json

List campaign recipients

GET

/campaigns/{campaignid}/bounces.json

List campaign bounces

GET

/clients/{clientid}/lists.json

List subscriber lists for a client

POST

/clients/{clientid}/suppress.json

Suppress email addresses for a client

POST

/clients.json

Create a client workspace

POST

/campaigns/{clientid}.json

Create a draft campaign for a client

POST

/campaigns/{campaignid}/send.json

Send a draft campaign

GET

/campaigns/{campaignid}/recipients.json

List campaign recipients

GET

/campaigns/{campaignid}/bounces.json

List campaign bounces

Why though Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

Campaign Monitor API keys or OAuth tokens are stored encrypted in the Jentic vault. Agents receive scoped execution rights and Jentic injects the credential into the Authorization header at call time, so the raw secret never enters the agent's context.

Intent-based discovery

Agents search by intent (for example, 'send an email campaign') and Jentic returns the matching Campaign Monitor operation along with its input schema, so the agent can call /campaigns/{campaignid}/send.json without browsing the Campaign Monitor docs.

Time to first call

Direct Campaign Monitor integration: 2-3 days for OAuth setup, multi-client routing, and bounce-handling logic. Through Jentic: under two hours to search, load, and execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Alternative

Mailchimp Marketing API

Mailchimp offers a broader marketing platform with audiences, automations, and e-commerce, where Campaign Monitor focuses on multi-client agency-style campaign management.

Choose Mailchimp for self-serve SMB marketers who need built-in e-commerce integrations; choose Campaign Monitor when an agency manages campaigns for many client brands.

Complementary

SendGrid Mail Send API

SendGrid Mail focuses on high-volume transactional email delivery, where Campaign Monitor's strength is marketing campaign orchestration and reporting.

Pair SendGrid for transactional sends with Campaign Monitor for marketing campaigns, segments, and journeys.

Alternative

Constant Contact API

Constant Contact targets small-business email marketing, where Campaign Monitor offers stronger agency multi-client features.

Choose Constant Contact for a single small-business sender; choose Campaign Monitor when the agent must operate across many client workspaces.

FAQs

Specific to using Campaign Monitor API API through Jentic.

Why is there no official OpenAPI spec for Campaign Monitor API?

Campaign Monitor does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Campaign Monitor API via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.

What authentication does the Campaign Monitor API use?

It supports HTTP Basic auth (API key as username, any value as password) or OAuth 2.0 authorization-code flow against https://api.createsend.com/oauth. Through Jentic, either credential type is held in the Jentic vault and injected at execution time so it never enters the agent's prompt context.

Can I send a campaign through Jentic?

Yes. Search 'send an email campaign' through the Jentic SDK. Jentic returns POST /campaigns/{campaignid}/send.json with its input schema. Provide the campaign ID from a prior draft creation and execute the operation to dispatch the campaign.

How do I retrieve the bounce report for a sent campaign?

Call GET /campaigns/{campaignid}/bounces.json with the campaign ID. The response paginates through hard and soft bounces, which you can then write to a CRM or suppression list using POST /clients/{clientid}/suppress.json.

Does the API support multiple client workspaces under one agency account?

Yes. Use POST /clients.json to create a client workspace and the /clients/{clientid}/* routes (lists, segments, campaigns, suppression) to manage that client's data in isolation while the agency operates from a single account.

Are transactional emails available through this API?

Yes. The Transactional resource exposes endpoints for sending transactional messages outside of broadcast campaigns. Use them when an email is triggered by a user action rather than scheduled to a list.