Campaign Monitor

Campaign Monitor API

Campaign Monitor API as documented publicly: 6 operations. Contract generated from the documentation by API Evangelist (2026-10-21); not the provider's own document.

GitHub OpenAPI

Operations 6

POST /api/v3.2/clients.json Create a client with JSON input format. #
GET /api/v3.2/clients.xml Get a list of clients in XML format. #
POST /api/v3.2/clients.xml Create a client with XML input format. #
GET /api/{apiid}/clients.json Get a list of clients in JSON format. #
POST /deactivate Receive webhook notifications when a subscriber in your list is deactivated. #
POST /subscribe POST /subscribe #

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/campaignmonitor/refs/heads/main/openapi/_ae-authored/campaignmonitor-openapi-generated.yml

Schemas & Data

📊
JSONSchema
https://raw.githubusercontent.com/api-evangelist/campaignmonitor/refs/heads/main/json-schema/campaignmonitor-post-api-v32-clients-json-request-schema.json
📊
JSONSchema
https://raw.githubusercontent.com/api-evangelist/campaignmonitor/refs/heads/main/json-schema/campaignmonitor-post-api-v32-clients-xml-request-schema.json
📊
JSONSchema
https://raw.githubusercontent.com/api-evangelist/campaignmonitor/refs/heads/main/json-schema/campaignmonitor-post-deactivate-request-schema.json
📊
JSONSchema
https://raw.githubusercontent.com/api-evangelist/campaignmonitor/refs/heads/main/json-schema/campaignmonitor-get-api-apiid-clients-json-response-schema.json
📊
JSONSchema
https://raw.githubusercontent.com/api-evangelist/campaignmonitor/refs/heads/main/json-schema/campaignmonitor-get-api-v32-clients-xml-response-schema.json

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API 
curl "https://apis.io/api/v1/apis/campaignmonitor:campaignmonitor-api"
All apis 
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

campaignmonitor-openapi-generated.yml Raw ↑ 
openapi: 3.1.0
info:
  title: Campaign Monitor API
  version: '2026-10-21'
  description: 'GENERATED FROM DOCUMENTATION by API Evangelist on 2026-10-21: 6 operation(s) read from 4 public documentation page(s) (each operation
    names its page in x-source). This is not the provider''s published contract; Campaign Monitor has published no machine-readable contract that
    the pipeline could find. Engine: anthropic.'
  x-evidence-tiers:
    code-example: 2
    documentation: 4
    pages-with-code: 4
    pages-read: 4
  x-generated-from: documentation
  x-provenance: generated
  x-authored-by: API Evangelist
  x-generated: '2026-10-21'
  x-generator: generate-contract-from-docs.py
  x-engine: anthropic
  x-sources:
  - https://www.campaignmonitor.com/api/v3-3/webhooks
  - https://www.campaignmonitor.com/api/v3-3/getting-started
  - https://www.campaignmonitor.com/api/v3-2/getting-started
  - https://www.campaignmonitor.com/api/v3-2/webhooks
servers:
- url: https://api.createsend.com
paths:
  /api/v3.2/clients.json:
    post:
      operationId: post_api_v3_2_clients_json
      tags:
      - Api
      summary: Create a client with JSON input format.
      x-source: https://www.campaignmonitor.com/api/v3-3/getting-started
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/PostApiV32ClientsJsonRequest'
      responses:
        '201':
          description: Success (status as documented)
      x-evidence:
        kind: documentation
  /api/v3.2/clients.xml:
    get:
      operationId: get_api_v3_2_clients_xml
      tags:
      - Api
      summary: Get a list of clients in XML format.
      x-source: https://www.campaignmonitor.com/api/v3-3/getting-started
      responses:
        '200':
          description: Success (status as documented)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GetApiV32ClientsXmlResponse'
      x-evidence:
        kind: documentation
    post:
      operationId: post_api_v3_2_clients_xml
      tags:
      - Api
      summary: Create a client with XML input format.
      x-source: https://www.campaignmonitor.com/api/v3-3/getting-started
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/PostApiV32ClientsXmlRequest'
      responses:
        '201':
          description: Success (status as documented)
      x-evidence:
        kind: documentation
  /api/{apiid}/clients.json:
    get:
      operationId: get_api_apiid_clients_json
      tags:
      - Api
      summary: Get a list of clients in JSON format.
      x-source: https://www.campaignmonitor.com/api/v3-3/getting-started
      parameters:
      - name: apiid
        in: path
        required: true
        schema:
          type: string
      - name: pretty
        in: query
        required: false
        schema:
          type: string
      responses:
        '200':
          description: Success (shape read from the example response on the page)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GetApiApiidClientsJsonResponse'
      x-evidence:
        kind: documentation
        collapsed_from: 2 example path(s) differing only at apiId
  /deactivate:
    post:
      operationId: post_deactivate
      tags:
      - Deactivate
      summary: Receive webhook notifications when a subscriber in your list is deactivated.
      x-source: https://www.campaignmonitor.com/api/v3-3/webhooks
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/PostDeactivateRequest'
      responses:
        '201':
          description: Success (status as documented)
      x-evidence:
        kind: documentation
  /subscribe:
    post:
      operationId: post_subscribe
      tags:
      - Subscribe
      summary: POST /subscribe
      x-source: https://www.campaignmonitor.com/api/v3-3/webhooks
      responses:
        '201':
          description: Success (status as documented)
      x-evidence:
        kind: code-example
        language: http
        snippet: " POST /subscribe HTTP/1.1 \nHost: example.com:80 \nAccept: */* \nContent-Type: application/json \n{ \n \"Events\": [ \n { \n\
          \ \"CustomFields\": [ \n { \n \"Key\": \"website\", \n \"Value\": \"https://example.org\" \n } \n ], \n \"Date\": \"2010-12-14 11:32:00\"\
          , \n \"EmailAddress\": \" [email protected] \", \n \"Name\": \"Test Subscriber\", \n \"SignupIPAddress\": \"53.78.123.243\", \n \"Type\"\
          : \"Subscribe\" \n } \n ], \n \"ListID\": \"96c0bbdaa54760c"
components:
  schemas:
    PostApiV32ClientsJsonRequest:
      type: object
      properties:
        CompanyName:
          type: string
        ContactName:
          type: string
        EmailAddress:
          type: string
        TimeZone:
          type: string
        Country:
          type: string
      required:
      - CompanyName
      - ContactName
      - EmailAddress
      - TimeZone
      - Country
    GetApiV32ClientsXmlResponse:
      type: object
      properties:
        ClientID:
          type: string
        Name:
          type: string
    PostApiV32ClientsXmlRequest:
      type: object
      properties:
        CompanyName:
          type: string
        ContactName:
          type: string
        EmailAddress:
          type: string
        TimeZone:
          type: string
        Country:
          type: string
      required:
      - CompanyName
      - ContactName
      - EmailAddress
      - TimeZone
      - Country
    GetApiApiidClientsJsonResponse:
      type: object
      properties:
        ClientID:
          type: string
        Name:
          type: string
    PostDeactivateRequest:
      type: object
      properties:
        Events:
          type: array
          description: Array of event objects containing deactivation details
        ListID:
          type: string
          description: The ID of the list where the deactivation occurred
      required:
      - Events
      - ListID
  securitySchemes:
    bearer:
      type: http
      scheme: bearer
security:
- bearer: []
tags:
- name: Api
- name: Deactivate
- name: Subscribe