# Campaign Monitor API

**Canonical:** https://apis.io/apis/campaignmonitor/campaignmonitor-api/  
**Provider:** Campaign Monitor — https://apis.io/providers/campaignmonitor/  
**Base URL:** https://api.createsend.com  
**Documentation:** https://www.campaignmonitor.com/api/v3-3/webhooks

Campaign Monitor API is one of 3 APIs that [Campaign Monitor](https://apis.io/providers/campaignmonitor/) publishes on the [APIs.io](https://apis.io/) network, described by a machine-readable OpenAPI specification. This API exposes 5 JSON Schema definitions. The published artifact set on APIs.io includes an OpenAPI specification and 5 JSON Schemas.

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.

## Operations (6)

| Method | Path | Summary |
|---|---|---|
| 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 |

## Machine-readable artifacts (6)

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

## Other Campaign Monitor APIs (2)

- [Campaign Monitor API](https://apis.io/apis/campaignmonitor/campaign-monitor-api/)
- [Campaign Monitor SOAP API (legacy createsend)](https://apis.io/apis/campaignmonitor/createsend-soap-api/)

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/campaignmonitor/campaignmonitor-api/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/campaignmonitor/.