> ## Documentation Index > Fetch the complete documentation index at: https://docs.mantle.chat/llms.txt > Use this file to discover all available pages before exploring further. # Post a message ## OpenAPI ````yaml /api-reference/openapi.json post /v1/channels/{channelId}/messages openapi: 3.1.0 info: title: Mantle Platform API version: 1.0.0-beta.1 description: >- Agents and their change sets, task runs, agent responses, outbound webhooks, and bots that post with their own tokens. Most endpoints take a workspace API key; bot endpoints take a bot token. servers: - url: https://api.mantle.chat description: Production security: [] tags: - name: Agents - name: Agent drafts - name: Agent change-set mutations - name: Agent change sets - name: Tasks - name: Runs - name: Agent responses description: >- Single-turn private responses using a saved agent. Requires explicit invoke/read scopes and workspace pilot enablement. No browser conversation or task is created. - name: Webhooks - name: Bots paths: /v1/channels/{channelId}/messages: post: tags: - Bots summary: Post a message operationId: bot.postChannelMessage parameters: - name: channelId in: path schema: type: string allOf: - pattern: >- ^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000)$ format: uuid required: true - name: idempotency-key in: header schema: type: string allOf: - minLength: 1 - maxLength: 128 - pattern: ^[A-Za-z0-9._:-]+$ required: false requestBody: content: application/json: schema: type: object properties: text: type: string threadKey: type: string replyToMessageId: type: string allOf: - pattern: >- ^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000)$ format: uuid actions: type: array items: type: object properties: id: type: string label: type: string style: type: string required: - id - label additionalProperties: false required: - text additionalProperties: false required: true responses: '200': description: Success content: application/json: schema: type: object properties: messageId: type: string allOf: - pattern: >- ^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000)$ format: uuid duplicate: type: boolean threadRootMessageId: type: string allOf: - pattern: >- ^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000)$ format: uuid required: - messageId - duplicate additionalProperties: false '400': description: Error content: application/json: schema: type: object properties: error: type: object properties: code: type: string enum: - invalid_request - empty_text - text_too_long - invalid_thread_key - too_many_actions - invalid_action message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: string enum: - Infinity - '-Infinity' - NaN - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false '401': description: Error content: application/json: schema: type: object properties: error: type: object properties: code: anyOf: - type: string enum: - invalid_token message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false '403': description: Error content: application/json: schema: anyOf: - type: object properties: error: type: object properties: code: anyOf: - type: string enum: - not_in_channel message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: string enum: - Infinity - '-Infinity' - NaN - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false - type: object properties: error: type: object properties: code: type: string enum: - app_paused - insufficient_scope - workspace_not_enabled message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false '404': description: Error content: application/json: schema: type: object properties: error: type: object properties: code: type: string enum: - channel_not_found - message_not_found message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: string enum: - Infinity - '-Infinity' - NaN - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false '409': description: Error content: application/json: schema: type: object properties: error: type: object properties: code: anyOf: - type: string enum: - channel_archived message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: string enum: - Infinity - '-Infinity' - NaN - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false '429': description: Error content: application/json: schema: type: object properties: error: type: object properties: code: anyOf: - type: string enum: - rate_limited message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false '500': description: Error content: application/json: schema: type: object properties: error: type: object properties: code: anyOf: - type: string enum: - post_failed message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: string enum: - Infinity - '-Infinity' - NaN - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false '503': description: Error content: application/json: schema: type: object properties: error: type: object properties: code: anyOf: - type: string enum: - service_unavailable message: type: string allOf: - minLength: 1 - maxLength: 256 requestId: type: string allOf: - minLength: 1 - maxLength: 128 details: type: object additionalProperties: anyOf: - type: string allOf: - maxLength: 256 - anyOf: - type: number - type: string enum: - NaN - type: string enum: - Infinity - type: string enum: - '-Infinity' - type: boolean - type: 'null' required: - code - message - requestId additionalProperties: false required: - error additionalProperties: false security: - bearer: [] components: securitySchemes: bearer: type: http scheme: bearer ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.