> ## Documentation Index > Fetch the complete documentation index at: https://www.quo.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Send a message > Send a text message from your Quo number to one or more recipients. ## OpenAPI ````yaml https://openphone-public-api-prod.s3.us-west-2.amazonaws.com/public/openphone-public-api-2026-03-30-prod.json post /messages openapi: 3.1.0 info: title: Quo Public API version: 1.0.0 description: API for connecting with Quo. contact: name: Quo Support email: support@quo.com url: https://support.quo.com/ termsOfService: https://www.quo.com/terms servers: - description: Production server url: https://api.quo.com security: - apiKey: [] tags: - description: Operations related to the organization's A2P registration name: A2P Registration - description: Operations related to calls placed by an AI agent name: Agent Calls - description: Operations related to text conversations held by an AI agent name: Agent Conversations - description: Operations related to calls name: Calls - description: >- Operations related to call summaries, including AI-generated summaries and Sona voice assistant summaries name: Call Summaries - description: >- Operations related to call transcripts, including AI-generated transcripts and Sona voice assistant transcripts name: Call Transcripts - description: Operations related to contacts name: Contacts - description: Operations related to contact shares name: Contact Shares - description: Operations related to contact notes name: Contact Notes - description: Operations related to contact properties name: Contact Properties - description: Operations related to conversations name: Conversations - description: Operations related to workspace invitations name: Invites - description: Operations related to text messages name: Messages - description: Operations related to the organization name: Organization - description: Operations related to phone numbers name: Phone Numbers - description: Operations related to users name: Users - description: Operations related to webhooks name: Webhooks - description: >- Operations related to webhook events, including delivery history and test events name: Webhook Events paths: /messages: post: tags: - Messages summary: Send a message description: Send a text message from your Quo number to one or more recipients. operationId: sendMessage parameters: - in: header name: Quo-Api-Version required: true schema: type: string enum: - '2026-03-30' description: 'API version header. Supported values: 2026-03-30' requestBody: required: true content: application/json: schema: type: object required: - content - from - to properties: content: type: string minLength: 1 maxLength: 1600 description: The content of your message. examples: - Good morning, your service appointment has been booked. example: Good morning, your service appointment has been booked. from: description: >- The ID of the Quo phone number to send from. The sender must be a user on this number. examples: - PN123abc example: PN123abc type: string pattern: ^PN(.*)$ to: type: array items: anyOf: - type: string description: >- A phone number in E.164 format, including the country code. examples: - '+15555555555' pattern: ^\+[1-9]\d{1,14}$ example: '+15555555555' - type: string description: Short code phone number (3-8 digits, no country code) pattern: ^[0-9]{3,8}$ description: >- A recipient phone number in E.164 format, or a short code (3-8 digits). examples: - '+15555555555' - '12345' example: '+15555555555' minItems: 1 maxItems: 10 description: >- The recipients of the message, each a phone number in E.164 format or a short code (3-8 digits). More than one sends a group message. At most 10. examples: - - '+15555555555' - - '+15555555555' - '+15555555556' example: - '+15555555555' senderUserId: anyOf: - description: >- The unique identifier of the Quo user sending the message. If not provided, the message is attributed to the owner of the phone number it is sent from. The sending user must be a member of the phone number the message is sent from. type: string pattern: ^US(.*)$ - type: 'null' inboxStatus: anyOf: - description: >- Used to set the status of the related Quo inbox conversation. The default behavior without setting this parameter will be for the message sent to show up as an open conversation in the user's inbox. Setting the parameter to 'done' would move the conversation to the Done inbox view. examples: - done example: done type: string const: done - type: 'null' responses: '202': description: Accepted content: application/json: schema: type: object required: - data properties: data: type: object required: - id - to - from - text - conversationId - direction - status - createdAt - updatedAt - media properties: id: description: The unique identifier of the message. examples: - AC123abc example: AC123abc type: string pattern: ^AC(.*)$ to: type: array items: anyOf: - type: string description: >- A phone number in E.164 format, including the country code. examples: - '+15555555555' pattern: ^\+[1-9]\d{1,14}$ example: '+15555555555' - type: string description: >- Short code phone number (3-8 digits, no country code) pattern: ^[0-9]{3,8}$ - type: string pattern: >- ^([aA](nonymous|NONYMOUS))|([bB](locked|LOCKED))|([rR](estricted|ESTRICTED))$ - type: string description: >- A phone number in E.164 format, a short code (3-8 digits), a non-phone-number caller ID (Anonymous, Restricted, or Blocked), or another value as delivered by the carrier, such as an alphanumeric sender ID. examples: - '+15555555555' - '12345' - Anonymous example: '+15555555555' description: >- Recipients of the message. Includes your Quo number for incoming messages. from: anyOf: - type: string description: >- A phone number in E.164 format, including the country code. examples: - '+15555555555' pattern: ^\+[1-9]\d{1,14}$ example: '+15555555555' - type: string description: >- Short code phone number (3-8 digits, no country code) pattern: ^[0-9]{3,8}$ - type: string pattern: >- ^([aA](nonymous|NONYMOUS))|([bB](locked|LOCKED))|([rR](estricted|ESTRICTED))$ - type: string description: >- A phone number in E.164 format, a short code (3-8 digits), a non-phone-number caller ID (Anonymous, Restricted, or Blocked), or another value as delivered by the carrier, such as an alphanumeric sender ID. examples: - '+15555555555' - '12345' - Anonymous example: '+15555555555' text: type: string description: The content of the message. examples: - Hello, world! example: Hello, world! phoneNumberId: anyOf: - description: >- The unique identifier of the Quo phone number that the message was sent from. examples: - PN123abc example: PN123abc type: string pattern: ^PN(.*)$ - type: 'null' conversationId: description: The unique identifier of the conversation. examples: - CN123abc example: CN123abc type: string pattern: ^CN(.*)$ direction: type: string enum: - incoming - outgoing description: >- The direction of the message relative to the Quo number. examples: - incoming example: incoming userId: anyOf: - description: >- The unique identifier of the user or system actor (e.g. Sona) who sent the message. Null for incoming messages. examples: - US123abc example: US123abc anyOf: - type: string pattern: ^US(.*)$ - type: string pattern: ^SYU(.*)$ - type: 'null' status: type: string enum: - queued - sent - delivered - undelivered - received - failed description: The status of the message. examples: - sent example: sent createdAt: description: >- The timestamp when the message was created, in ISO 8601 format. examples: - '2022-01-01T00:00:00Z' example: '2022-01-01T00:00:00Z' type: string format: date-time updatedAt: description: >- The timestamp when the message status was last updated, in ISO 8601 format. examples: - '2022-01-01T00:00:00Z' example: '2022-01-01T00:00:00Z' type: string format: date-time media: type: array items: type: object required: - url properties: url: type: string description: The URL of the attached media. examples: - https://example.com/image.png example: https://example.com/image.png type: anyOf: - type: string description: The MIME type of the attached media. examples: - image/png example: image/png - type: 'null' description: Media attached to the message. '400': description: >- Bad Request | Invalid `to` Phone Number | Unreachable `to` Phone Number | User Opted Out | Not TFN Registered | A2P Registration Not Approved content: application/json: schema: oneOf: - $ref: '#/components/schemas/BadRequestError' - $ref: '#/components/schemas/InvalidToPhoneNumberError' - $ref: '#/components/schemas/UnreachableToPhoneNumberError' - $ref: '#/components/schemas/UserOptedOutError' - $ref: '#/components/schemas/NotTFNRegisteredError' - $ref: '#/components/schemas/A2PRegistrationNotApprovedError' examples: BadRequestError: summary: Bad Request value: message: The input was invalid docs: https://quo.com/docs title: Bad Request errors: - path: /messageId message: Expected string to match '^AC(.*)$' value: abc123 schema: type: TemplateLiteral pattern: ^AC(.*)$ InvalidToPhoneNumberError: summary: Invalid `to` Phone Number value: message: At least one recipient in `to` is invalid docs: https://quo.com/docs title: Invalid `to` Phone Number trace: '6897907457496870895' UnreachableToPhoneNumberError: summary: Unreachable `to` Phone Number value: message: >- At least one recipient in `to` is not currently reachable via SMS docs: https://quo.com/docs title: Unreachable `to` Phone Number trace: '6897907457496870895' UserOptedOutError: summary: User Opted Out value: message: User has opted out of receiving messages docs: https://quo.com/docs title: User Opted Out trace: '6897907457496870895' NotTFNRegisteredError: summary: Not TFN Registered value: message: >- The toll-free phone number is not registered for TFN messaging docs: https://quo.com/docs title: Not TFN Registered trace: '6897907457496870895' A2PRegistrationNotApprovedError: summary: A2P Registration Not Approved value: message: The organization is not approved for A2P docs: https://quo.com/docs title: A2P Registration Not Approved trace: '6897907457496870895' '401': description: Unauthorized content: application/json: schema: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Unauthorized trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string example: message: Unauthorized docs: https://quo.com/docs title: Unauthorized trace: '6897907457496870895' '402': description: Not Enough Credits | Subscription Expired content: application/json: schema: oneOf: - $ref: '#/components/schemas/NotEnoughCreditsError' - $ref: '#/components/schemas/SubscriptionExpiredError' examples: NotEnoughCreditsError: summary: Not Enough Credits value: message: >- The organization does not have enough prepaid credits to send the message docs: https://quo.com/docs title: Not Enough Credits trace: '6897907457496870895' SubscriptionExpiredError: summary: Subscription Expired value: message: Your subscription has expired docs: https://quo.com/docs title: Subscription Expired trace: '6897907457496870895' '403': description: >- Forbidden | Not Phone Number User | A2P 10DLC Daily Message Cap Reached | International Messaging Not Allowed content: application/json: schema: oneOf: - $ref: '#/components/schemas/ForbiddenError' - $ref: '#/components/schemas/NotPhoneNumberUserError' - $ref: '#/components/schemas/A2P10DLCDailyMessageCapReachedError' - $ref: '#/components/schemas/InternationalMessagingNotAllowedError' examples: ForbiddenError: summary: Forbidden value: message: The user is forbidden from accessing the message docs: https://quo.com/docs title: Forbidden trace: '6897907457496870895' NotPhoneNumberUserError: summary: Not Phone Number User value: message: >- Sender not authorized to send messages from this phone number. docs: https://quo.com/docs title: Not Phone Number User trace: '6897907457496870895' A2P10DLCDailyMessageCapReachedError: summary: A2P 10DLC Daily Message Cap Reached value: message: >- A2P 10DLC Daily limit reached. For help increasing this limit, visit https://support.quo.com/help/submit-a-request docs: https://quo.com/docs title: A2P 10DLC Daily Message Cap Reached trace: '6897907457496870895' InternationalMessagingNotAllowedError: summary: International Messaging Not Allowed value: message: >- International messaging is not enabled for the sender phone number docs: https://quo.com/docs title: International Messaging Not Allowed trace: '6897907457496870895' '404': description: Not Found content: application/json: schema: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Not Found trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string example: message: Message not found docs: https://quo.com/docs title: Not Found trace: '6897907457496870895' '422': description: Unprocessable Entity content: application/json: schema: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Unprocessable Entity trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string example: message: The message has permanently failed and cannot be retried docs: https://quo.com/docs title: Unprocessable Entity trace: '6897907457496870895' '429': description: Too Many Requests content: application/json: schema: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Too Many Requests trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string example: message: >- The organization has reached its limit for starting new conversations. Try again later. docs: https://quo.com/docs title: Too Many Requests trace: '6897907457496870895' '500': description: Unexpected Error | Unknown Error content: application/json: schema: oneOf: - $ref: '#/components/schemas/UnexpectedError' - $ref: '#/components/schemas/UnknownError' examples: UnexpectedError: summary: Unexpected Error value: message: We have encountered an unknown error docs: https://quo.com/docs title: Unexpected trace: '6897907457496870895' UnknownError: summary: Unknown Error value: message: We have encountered an unknown error docs: https://quo.com/docs title: Unknown trace: '6897907457496870895' security: - apiKey: [] components: schemas: BadRequestError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Bad Request trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Bad Request InvalidToPhoneNumberError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Invalid `to` Phone Number trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Invalid `to` Phone Number UnreachableToPhoneNumberError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Unreachable `to` Phone Number trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Unreachable `to` Phone Number UserOptedOutError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: User Opted Out trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: User Opted Out NotTFNRegisteredError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Not TFN Registered trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Not TFN Registered A2PRegistrationNotApprovedError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: A2P Registration Not Approved trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: A2P Registration Not Approved NotEnoughCreditsError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Not Enough Credits trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Not Enough Credits SubscriptionExpiredError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Subscription Expired trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Subscription Expired ForbiddenError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Forbidden trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Forbidden NotPhoneNumberUserError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Not Phone Number User trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Not Phone Number User A2P10DLCDailyMessageCapReachedError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: A2P 10DLC Daily Message Cap Reached trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: A2P 10DLC Daily Message Cap Reached InternationalMessagingNotAllowedError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: International Messaging Not Allowed trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: International Messaging Not Allowed UnexpectedError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Unexpected trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Unexpected Error UnknownError: type: object required: - message - docs - title properties: message: type: string docs: type: string const: https://quo.com/docs title: type: string const: Unknown trace: type: string errors: type: array items: type: object required: - path - message - schema properties: path: type: string message: type: string value: {} schema: type: object properties: type: type: string title: Unknown Error securitySchemes: apiKey: in: header name: Authorization type: apiKey ````