# AT&T In-App Messaging API

**Canonical:** https://apis.io/apis/at-and-t/att-in-app-messaging-api/  
**Provider:** AT&T — https://apis.io/providers/at-and-t/  
**Base URL:** https://api.att.com  
**Documentation:** https://developer.att.com/in-app-messaging

AT&T In-App Messaging API is one of 5 APIs that [AT&T](https://apis.io/providers/at-and-t/) publishes on the [APIs.io](https://apis.io/) network, described by a machine-readable OpenAPI specification. Tagged areas include MMS, SMS, Messaging, In-App, and Inbox. The published artifact set on APIs.io includes API documentation, authentication docs, and an OpenAPI specification.

A messaging API enabling applications to send, receive, update, and delete MMS and SMS messages on behalf of users with explicit consent. Supports messages to phone numbers, short codes, and email addresses across AT&T and other carriers, with inbox management and delta synchronization.

## Machine-readable artifacts (3)

- **Documentation** — https://developer.att.com/in-app-messaging/docs
- **Authentication** — https://developer.att.com/oauth-2/docs
- **OpenAPI** — https://artifacts.apis.io/at-and-t/openapi/at-and-t-in-app-messaging-api.yaml

## Other AT&T APIs (4)

- [AT&T SMS API](https://apis.io/apis/at-and-t/att-sms-api/)
- [AT&T OAuth 2.0 API](https://apis.io/apis/at-and-t/att-oauth-api/)
- [AT&T MVNX API](https://apis.io/apis/at-and-t/att-mvnx-api/)
- [AT&T Alliance Wireline APIs](https://apis.io/apis/at-and-t/att-alliance-wireline-apis/)

## Tags

MMS, SMS, Messaging, In-App, Inbox

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/at-and-t/att-in-app-messaging-api/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/at-and-t/.