> ## Documentation Index
> Fetch the complete documentation index at: https://docs.capy.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Send message



## OpenAPI

````yaml /openapi.json post /api/v1/threads/{threadId}/message
openapi: 3.1.0
info:
  title: Capy API
  version: 1.0.0
  description: Programmatic access to Capy's agent platform.
servers:
  - url: https://api.capy.ai
security:
  - bearerAuth: []
tags:
  - name: threads
  - name: tasks
  - name: messages
  - name: reviews
  - name: usage
paths:
  /api/v1/threads/{threadId}/message:
    post:
      tags:
        - messages
      summary: Send message
      operationId: messages.send
      parameters:
        - name: threadId
          in: path
          schema:
            type: string
          required: true
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendMessageRequest'
        required: true
      responses:
        '200':
          description: AdmitReceipt
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AdmitReceipt'
        '401':
          description: capy/Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/capy_Unauthorized'
        '404':
          description: capy/ThreadNotFound
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/capy_ThreadNotFound'
      security:
        - bearerAuth: []
components:
  schemas:
    SendMessageRequest:
      type: object
      properties:
        text:
          type: string
        model:
          type: object
          properties:
            modelId:
              type: string
            reasoningMode:
              type: string
              enum:
                - none
                - minimal
                - low
                - medium
                - high
                - xhigh
                - max
            modes:
              type: object
              properties:
                fast:
                  type: boolean
                pro:
                  type: boolean
              additionalProperties: false
          required:
            - modelId
          additionalProperties: false
        delivery:
          type: string
          enum:
            - queue
            - steer
            - interrupt
      required:
        - text
      additionalProperties: false
    AdmitReceipt:
      type: object
      properties:
        id:
          type: string
          allOf:
            - minLength: 26
            - maxLength: 26
        deduped:
          type: boolean
      required:
        - id
        - deduped
      additionalProperties: false
    capy_Unauthorized:
      type: object
      properties:
        _tag:
          type: string
          enum:
            - capy/Unauthorized
      required:
        - _tag
      additionalProperties: false
    capy_ThreadNotFound:
      type: object
      properties:
        _tag:
          type: string
          enum:
            - capy/ThreadNotFound
        threadId:
          type: string
      required:
        - _tag
        - threadId
      additionalProperties: false
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: Capy API key
      description: An API key created in Capy under Settings → API.

````