Campaign Monitor API
Agent-ready OpenAPI document · curated by JenticMarketingEmail Marketingbasic, oauth272 EndpointsREST
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For Agents
Manage email-marketing clients, lists, subscribers, campaigns, segments, templates, journeys, and transactional sends through a multi-tenant agency-friendly API.
Use for: Create a draft email campaign for a specific client, Send an existing draft campaign to its target list, Get the bounce report for a sent campaign, List all subscriber lists belonging to a client
Not supported: Does not handle SMS, push notifications, paid advertising, or CRM contact management - use for email-marketing campaign and subscriber operations only.
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.
Install Jentic One Beta
Connect the Campaign Monitor API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Campaign Monitor API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fcampaignmonitor.com%2Fcampaignmonitor" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fcampaignmonitor.com%2Fcampaignmonitor" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Campaign Monitor 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
Suppress and unsuppress email addresses at the client level to honour unsubscribes
Send transactional and template-based email through the Transactional and Templates resources
Send campaign previews to test addresses before broadcast via /campaigns/{campaignid}/sendpreview.json
Use Cases
Patterns agents use Campaign Monitor 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
GET
/clients/{clientid}/lists.json
List subscriber lists for a client
POST
/clients/{clientid}/suppress.json
Suppress email addresses for a client
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Campaign Monitor API by hand means choosing between HTTP Basic keys and OAuth 2.0, then finding the right client, campaign, and list routes across 72 operations. Through Jentic you install once, import Campaign Monitor from the API Directory, store the credential once, and your agent calls it.
Permission scoping
Campaign Monitor puts the client id in the URL path (/clients/{clientid}/lists.json), so a rule can pin your agent to one client: it can manage that client's campaigns and lists and nothing else. You choose the operations it may call, so sending a campaign or suppressing subscribers is not included unless you add it.
Credential isolation
Your Campaign Monitor key or OAuth token is stored once, encrypted, by your own Jentic One instance and injected into the Authorization header at execution time. It never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'send an email campaign' or 'list a client's subscriber lists', and Jentic returns the matching Campaign Monitor operation with its input schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Campaign Monitor 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 with Jentic One, the self-hosted execution layer.
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 your Jentic One instance 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.
Can I limit what my agent is allowed to do with the Campaign Monitor API?
Yes. Because you run Jentic One yourself, your own rules decide which Campaign Monitor operations and credentials the agent may use. Campaign Monitor puts the client id in the URL path, such as /clients/{clientid}/lists.json, so a rule can pin the agent to a single client and let it manage only that client's lists and campaigns. You also choose the specific operations it can call, so higher-impact actions like POST /campaigns/{campaignid}/send.json or POST /clients/{clientid}/suppress.json are excluded unless you add them.
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