# SmartChat API

> Send WhatsApp messages and manage contacts, templates, newsletters, automations and your landing page from your own software or from an AI assistant.

Last updated: 2026-10-30. Source: https://docs.smartchat.marketing/en/

The SmartChat API lets your software do what you do in the SmartChat app: read and save contacts, send a message, prepare and send a newsletter, build an automation, edit the landing page and get notified when something happens. The **MCP server** gives AI assistants such as Claude and ChatGPT most of these abilities. Some calls are REST only: see [REST to MCP](https://docs.smartchat.marketing/en/mcp/rest-coverage/).

Everything is English: field names, values, error codes and tool names. There is one error format, one way to page through lists and one way to repeat a call safely.

## Start here

| I want to... | Go to |
|---|---|
| Make my first call in under 5 minutes | [Quickstart](https://docs.smartchat.marketing/en/quickstart/) |
| Create a key and choose its permissions | [Authentication](https://docs.smartchat.marketing/en/authentication/) |
| Look up a call | [API reference](https://docs.smartchat.marketing/en/api/) |
| Understand errors, lists and retries | [Concepts](https://docs.smartchat.marketing/en/concepts/conventions/) |
| Follow a complete example | [Guides](https://docs.smartchat.marketing/en/guides/create-a-contact/) |
| Get notified when something happens | [Webhooks](https://docs.smartchat.marketing/en/webhooks/overview/) |
| Connect Claude, ChatGPT, Zapier, Make or n8n | [MCP server](https://docs.smartchat.marketing/en/mcp/) |

## The facts in one table

| | |
|---|---|
| Base URL | `https://api.smartchat.marketing/v1` |
| Sign-in | `Authorization: Bearer <key>` ([details](https://docs.smartchat.marketing/en/authentication/)) |
| Format | JSON in, JSON out. Times are ISO 8601 in UTC. |
| Errors | One format for every error ([details](https://docs.smartchat.marketing/en/concepts/errors-overview/)) |
| Lists | Cursor pages, 20 items by default, at most 100 ([details](https://docs.smartchat.marketing/en/concepts/pagination/)) |
| Safety net | 120 requests per minute per key ([details](https://docs.smartchat.marketing/en/concepts/rate-limits/)) |
| Version | 2026-10-25, shown in the `SmartChat-Version` header ([details](https://docs.smartchat.marketing/en/concepts/versioning/)) |

## Machine-readable

- [OpenAPI (JSON)](https://docs.smartchat.marketing/openapi.json) and [OpenAPI (YAML)](https://docs.smartchat.marketing/openapi.yaml): the one source of the API description.
- [Postman collection](https://docs.smartchat.marketing/postman-collection.json).
- [llms.txt](https://docs.smartchat.marketing/llms.txt) and [all pages in one file](https://docs.smartchat.marketing/llms-full.txt) for AI assistants. Every page also exists as Markdown: add `.md` to the address.

> **Note** The earlier SmartChat API is replaced. Its keys, field names and error codes do not work any more. Create a new key and connect your assistants again. See the [changelog](https://docs.smartchat.marketing/en/changelog/).