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OpenAPI Specification
openapi: 3.2.0
info:
title: AT&T Wireless SMS API
description: Developer APIs for AT&T's wireless network capabilities including SMS messaging, MMS messaging, OAuth authentication, speech-to-text, text-to-speech, in-app messaging, and advertising APIs for consumer and business applications.
version: 1.0.0
contact:
name: AT&T Developer Support
url: https://developer.att.com/support
termsOfService: https://www.att.com/gen/general?pid=11561
servers:
- url: https://api.att.com
description: AT&T API Production Server
security:
- oauth2: []
tags:
- name: SMS
description: Short Message Service operations
paths:
/sms/v3/messaging/outbox:
post:
operationId: sendSms
summary: Send AT&T SMS Message
description: Send an SMS message to one or more recipients on the AT&T network.
tags:
- SMS
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/SendSmsRequest'
examples:
singleRecipient:
summary: Single Recipient SMS
value:
outboundSMSRequest:
address:
- tel:+12125551234
message: Hello from AT&T Developer API
responses:
'201':
description: SMS sent successfully
content:
application/json:
schema:
$ref: '#/components/schemas/SendSmsResponse'
examples:
success:
summary: SMS Sent
value:
outboundSMSResponse:
messageId: msg_abc123
resourceReference:
resourceURL: https://api.att.com/sms/v3/messaging/outbox/msg_abc123
'400':
description: Bad request
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
'401':
description: Unauthorized
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
/sms/v3/messaging/outbox/{messageId}:
get:
operationId: getSmsDeliveryStatus
summary: Get AT&T SMS Delivery Status
description: Retrieve the delivery status of a previously sent SMS message.
tags:
- SMS
parameters:
- name: messageId
in: path
required: true
description: The unique identifier of the SMS message
schema:
type: string
examples:
example:
value: msg_abc123
responses:
'200':
description: Delivery status retrieved successfully
content:
application/json:
schema:
$ref: '#/components/schemas/DeliveryInfoResponse'
examples:
delivered:
summary: Message Delivered
value:
deliveryInfoList:
deliveryInfo:
- address: tel:+12125551234
deliveryStatus: DeliveredToTerminal
'404':
description: Message not found
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
/sms/v3/messaging/inbox/{registrationId}:
get:
operationId: getInboundSms
summary: Get AT&T Inbound SMS Messages
description: Retrieve inbound SMS messages for a registered short code or long code.
tags:
- SMS
parameters:
- name: registrationId
in: path
required: true
description: The registration ID for the inbound message endpoint
schema:
type: string
examples:
example:
value: reg_xyz789
responses:
'200':
description: Inbound messages retrieved
content:
application/json:
schema:
$ref: '#/components/schemas/InboundSmsResponse'
examples:
messages:
summary: Inbound Messages
value:
inboundSMSMessageList:
inboundSMSMessage:
- messageId: in_msg_001
message: Reply text
senderAddress: tel:+12125559876
dateTime: '2026-04-19T10:00:00Z'
'404':
description: Registration not found
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
components:
schemas:
InboundSmsResponse:
type: object
properties:
inboundSMSMessageList:
type: object
properties:
inboundSMSMessage:
type: array
items:
$ref: '#/components/schemas/InboundSmsMessage'
SendSmsRequest:
type: object
required:
- outboundSMSRequest
properties:
outboundSMSRequest:
type: object
required:
- address
- message
properties:
address:
type: array
items:
type: string
description: 'List of recipient phone numbers in tel: URI format'
message:
type: string
maxLength: 160
description: SMS message text content
senderAddress:
type: string
description: Sender address or short code
SendSmsResponse:
type: object
properties:
outboundSMSResponse:
type: object
properties:
messageId:
type: string
description: Unique message identifier
resourceReference:
type: object
properties:
resourceURL:
type: string
format: uri
description: URL to check message status
ErrorResponse:
type: object
properties:
RequestError:
type: object
properties:
ServiceException:
type: object
properties:
MessageId:
type: string
Text:
type: string
Variables:
type: string
DeliveryInfoResponse:
type: object
properties:
deliveryInfoList:
type: object
properties:
deliveryInfo:
type: array
items:
$ref: '#/components/schemas/DeliveryInfo'
InboundSmsMessage:
type: object
properties:
messageId:
type: string
description: Unique message identifier
message:
type: string
description: SMS message text
senderAddress:
type: string
description: 'Sender phone number in tel: URI format'
destinationAddress:
type: string
description: Recipient address or short code
dateTime:
type: string
format: date-time
description: Message receipt timestamp
DeliveryInfo:
type: object
properties:
address:
type: string
description: Recipient address
deliveryStatus:
type: string
enum:
- DeliveredToTerminal
- DeliveryImpossible
- DeliveredToNetwork
- MessageWaiting
description: Message delivery status
securitySchemes:
oauth2:
type: oauth2
flows:
clientCredentials:
tokenUrl: https://api.att.com/oauth/v4/token
scopes:
SMS: Access SMS messaging APIs
MMS: Access MMS messaging APIs
SPEECH: Access speech recognition APIs
TTS: Access text-to-speech APIs
ADS: Access advertising APIs