> ## Documentation Index > Fetch the complete documentation index at: https://docs.asapp.com/llms.txt > Use this file to discover all available pages before exploring further. # Create a message > Creates a message object, adding it to an existing conversation. Use this endpoint to record each new message in the conversation. ## OpenAPI ````yaml post /conversation/v1/conversations/{conversationId}/messages openapi: 3.0.1 info: title: Conversations API description: Operations to manage ASAPP conversations contact: email: api-info@asapp.com license: name: ASAPP Software License url: https://api.asapp.com/LICENSE version: '0.1' servers: - url: https://api.sandbox.asapp.com security: - API-ID: [] API-Secret: [] tags: - name: Conversations description: Operations to send conversational inputs to ASAPP AI services paths: /conversation/v1/conversations/{conversationId}/messages: parameters: - name: conversationId description: The identifier for a conversation. in: path required: true schema: type: string pattern: ^[A-Z0-9]+$ post: tags: - Conversations summary: Create a message description: | Creates a message object, adding it to an existing conversation. Use this endpoint to record each new message in the conversation. operationId: createMessage requestBody: required: true content: application/json: schema: description: Represents a single message within a conversation. type: object properties: text: type: string minLength: 1 description: The content of the message. sender: description: Information about the participant who sent the message. type: object properties: role: description: The role of the participant in the conversation. type: string enum: - agent - customer - system externalId: type: string description: >- The unique identifier for the participant in your external system. This should be consistent across all interactions for the same individual. required: - role - externalId timestamp: type: string format: date-time description: >- The time when the message was sent. Include the timezone, otherwise UTC will be assumed. required: - text - sender - timestamp example: text: Hello, I would like to upgrade my internet plan to GOLD. sender: role: agent externalId: 123 timestamp: '2021-11-23T12:13:14.555Z' responses: '200': description: Successfully created message in conversation content: application/json: schema: description: Response for messages type: object properties: id: type: string description: Message ID to be used for analytics example: id: 01BX5ZZKBKACTAV9WEVGEMMVS1 '400': description: 400 - Bad request content: application/json: schema: description: Bad request response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 400-01 message: Bad request description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '401': description: 401 - Unauthorized content: application/json: schema: description: Unauthorized response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 401-01 message: Unauthorized description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '403': description: 403 - Forbidden content: application/json: schema: description: Forbidden response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 403-01 message: Forbidden Response description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '404': description: 404 - Not Found content: application/json: schema: description: Not Found response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 404-01 message: Not Found description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '409': description: 409 - Conflict content: application/json: schema: description: Conflict response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 409-01 message: Conflict description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '413': description: 413 - Request Entity Too Large content: application/json: schema: description: Request Entity Too Large response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 413-01 message: Request Entity Too Large description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '422': description: 422 - Unprocessable Entity content: application/json: schema: description: Unprocessable Entity response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 422-01 message: Unprocessable Entity description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '429': description: 429 - Too Many Requests content: application/json: schema: description: Too Many Requests response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 429-01 message: Too Many Requests description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message '503': description: 503 - Service Unavailable content: application/json: schema: description: Service Unavailable response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 503-01 message: Service Unavailable description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message default: description: 500 - Internal Server Error content: application/json: schema: description: Default error response type: object properties: error: example: requestId: 8e033668-9f1a-11ec-b909-0242ac120002 code: 500-01 message: Internal server error description: Error details type: object properties: requestId: type: string description: Unique ID of the failing request message: type: string description: Error message code: type: string description: Error code required: - requestId - message components: securitySchemes: API-ID: type: apiKey in: header name: asapp-api-id API-Secret: type: apiKey in: header name: asapp-api-secret ````