> ## Documentation Index > Fetch the complete documentation index at: https://test-8862363a-tembo-docs-commit-attribution-preference.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Create a message > Create a user message for a session and submit it to the session agent. ## OpenAPI ````yaml https://api.tembo.io/public-api/openapi/public post /v1/messages openapi: 3.1.0 info: title: Tembo Public API description: >- Manage agents, sessions, repositories, and organization resources with the Tembo API. version: 1.0.0 servers: - url: https://api.tembo.io description: Tembo API - url: https://{deployment-origin}/api/public-api description: Self-hosted Tembo variables: deployment-origin: default: tembo.example.com description: Hostname of your self-hosted Tembo deployment security: [] paths: /v1/messages: post: tags: - Messages summary: Create a message description: Create a user message for a session and submit it to the session agent. operationId: createMessage requestBody: required: true content: application/json: schema: type: object properties: artifactId: type: string format: uuid content: type: string minLength: 1 maxLength: 1000000 mcpServers: type: array items: type: string minLength: 1 maxLength: 200 maxItems: 100 pullRequestId: type: string format: uuid sessionId: type: string format: uuid agentOptions: $ref: '#/components/schemas/AgentOptionsInput' deliveryMode: type: string enum: - queue - steer richContent: $ref: '#/components/schemas/TipTapDocument' description: >- Optional rich-text representation of the message. Provide the required text content separately. slashCommand: type: object properties: command: type: string minLength: 1 maxLength: 200 arguments: type: string maxLength: 100000 required: - command additionalProperties: false required: - content - sessionId additionalProperties: false responses: '201': description: Create a message content: application/json: schema: type: object properties: hotPath: type: - object - 'null' properties: activeProviderTurnId: type: - string - 'null' mode: type: string enum: - started - steered - queued providerSessionId: type: - string - 'null' queuedTurnId: type: - string - 'null' transport: type: string additionalProperties: false job: type: - object - 'null' properties: id: type: string format: uuid task: type: string required: - id - task additionalProperties: false message: type: object properties: artifactId: type: - string - 'null' format: uuid content: type: string createdAt: type: string format: date-time createdBy: type: - string - 'null' externalAvatarUrl: type: - string - 'null' externalUrl: type: - string - 'null' id: type: string format: uuid parentMessageId: type: - string - 'null' format: uuid pullRequestId: type: - string - 'null' format: uuid role: type: string enum: - user - assistant - system sessionId: type: - string - 'null' format: uuid type: type: string updatedAt: type: string format: date-time richContent: oneOf: - $ref: '#/components/schemas/TipTapDocument' - type: 'null' description: >- Rich-text representation of the message, including formatting and mentions. The content field contains its text representation. slashCommand: type: - object - 'null' properties: command: type: string minLength: 1 maxLength: 200 arguments: type: string maxLength: 100000 required: - command additionalProperties: false source: type: - string - 'null' maxLength: 100 isQueued: type: boolean required: - artifactId - content - createdAt - createdBy - externalAvatarUrl - externalUrl - id - parentMessageId - pullRequestId - role - sessionId - type - updatedAt - richContent - slashCommand - source - isQueued additionalProperties: false session: type: object properties: id: type: string format: uuid title: type: string required: - id - title additionalProperties: false required: - hotPath - job - message - session additionalProperties: false '400': description: >- Invalid request or missing required organization or user information. content: application/json: schema: type: object properties: error: type: string required: - error additionalProperties: false '403': description: Creating a message requires credentials associated with a user. content: application/json: schema: type: object properties: error: type: string required: - error additionalProperties: false '404': description: Message or session not found content: application/json: schema: type: object properties: error: type: string required: - error additionalProperties: false '409': description: Message operation conflicts with its current state content: application/json: schema: type: object properties: error: type: string required: - error additionalProperties: false '500': description: Message operation failed content: application/json: schema: type: object properties: error: type: string required: - error additionalProperties: false security: - apiKey: [] components: schemas: AgentOptionsInput: anyOf: - type: object properties: reasoningLevel: type: string minLength: 1 maxLength: 100 mode: type: string enum: - normal - planning speed: type: string enum: - normal - fast goal: type: object properties: enabled: type: boolean objective: type: string maxLength: 100000 additionalProperties: false additionalProperties: true - $ref: '#/components/schemas/RuntimeAgentOptions' description: >- Execution settings for the selected agent runtime, including provider-specific options. TipTapDocument: anyOf: - $ref: '#/components/schemas/TipTapNode' - $ref: '#/components/schemas/CustomDocument' description: >- Rich-text document containing text, formatting, images, and mentions. A document typically has a "doc" root with nested content nodes. example: type: doc content: - type: paragraph content: - type: text text: Hello RuntimeAgentOptions: type: object additionalProperties: {} description: Runtime-specific execution settings and provider extensions. TipTapNode: anyOf: - oneOf: - type: object properties: text: type: string maxLength: 1000000 marks: type: array items: anyOf: - $ref: '#/components/schemas/TipTapLinkMark' - $ref: '#/components/schemas/TipTapMark' maxItems: 1000 type: type: string const: image attrs: $ref: '#/components/schemas/TipTapImageAttributes' content: type: array items: $ref: '#/components/schemas/TipTapNode' maxItems: 10000 required: - type additionalProperties: {} - type: object properties: text: type: string maxLength: 1000000 marks: type: array items: anyOf: - $ref: '#/components/schemas/TipTapLinkMark' - $ref: '#/components/schemas/TipTapMark' maxItems: 1000 type: type: string const: mention attrs: $ref: '#/components/schemas/TipTapMentionAttributes' content: type: array items: $ref: '#/components/schemas/TipTapNode' maxItems: 10000 required: - type additionalProperties: {} - type: object properties: text: type: string maxLength: 1000000 marks: type: array items: anyOf: - $ref: '#/components/schemas/TipTapLinkMark' - $ref: '#/components/schemas/TipTapMark' maxItems: 1000 type: type: string const: heading attrs: type: object properties: level: type: integer minimum: 1 maximum: 6 additionalProperties: {} content: type: array items: $ref: '#/components/schemas/TipTapNode' maxItems: 10000 required: - type additionalProperties: {} - type: object properties: text: type: string maxLength: 1000000 marks: type: array items: anyOf: - $ref: '#/components/schemas/TipTapLinkMark' - $ref: '#/components/schemas/TipTapMark' maxItems: 1000 type: type: string const: orderedList attrs: type: object properties: start: type: integer type: type: - string - 'null' additionalProperties: {} content: type: array items: $ref: '#/components/schemas/TipTapNode' maxItems: 10000 required: - type additionalProperties: {} - type: object properties: text: type: string maxLength: 1000000 marks: type: array items: anyOf: - $ref: '#/components/schemas/TipTapLinkMark' - $ref: '#/components/schemas/TipTapMark' maxItems: 1000 type: type: string const: taskItem attrs: type: object properties: checked: type: boolean additionalProperties: {} content: type: array items: $ref: '#/components/schemas/TipTapNode' maxItems: 10000 required: - type additionalProperties: {} - type: object properties: text: type: string maxLength: 1000000 marks: type: array items: anyOf: - $ref: '#/components/schemas/TipTapLinkMark' - $ref: '#/components/schemas/TipTapMark' maxItems: 1000 type: type: string const: codeBlock attrs: type: object properties: language: type: - string - 'null' additionalProperties: {} content: type: array items: $ref: '#/components/schemas/TipTapNode' maxItems: 10000 required: - type additionalProperties: {} - $ref: '#/components/schemas/TipTapContentNode' CustomDocument: type: object additionalProperties: {} description: Rich-text content with custom document properties and node attributes. TipTapLinkMark: type: object properties: type: type: string const: link attrs: type: object properties: href: type: - string - 'null' target: type: - string - 'null' rel: type: - string - 'null' class: type: - string - 'null' title: type: - string - 'null' additionalProperties: {} required: - type additionalProperties: {} TipTapMark: type: object properties: type: type: string minLength: 1 maxLength: 100 not: enum: - link attrs: $ref: '#/components/schemas/TipTapExtensionAttributes' required: - type additionalProperties: {} TipTapImageAttributes: type: object properties: src: type: - string - 'null' alt: type: - string - 'null' title: type: - string - 'null' width: type: - string - 'null' data-uploading: type: - string - 'null' data-placeholder-id: type: - string - 'null' upload-progress: type: - string - 'null' additionalProperties: {} TipTapMentionAttributes: type: object properties: id: type: - string - 'null' label: type: - string - 'null' type: type: - string - 'null' mentionSuggestionChar: type: - string - 'null' metadata: type: - object - 'null' properties: integrationType: type: string codeRepositoryId: type: string isHeader: type: boolean argumentHint: type: string commandName: type: string source: type: string additionalProperties: {} additionalProperties: {} TipTapContentNode: type: object properties: text: type: string maxLength: 1000000 marks: type: array items: anyOf: - $ref: '#/components/schemas/TipTapLinkMark' - $ref: '#/components/schemas/TipTapMark' maxItems: 1000 type: type: string minLength: 1 maxLength: 100 not: enum: - image - mention - heading - orderedList - taskItem - codeBlock attrs: $ref: '#/components/schemas/TipTapExtensionAttributes' content: type: array items: $ref: '#/components/schemas/TipTapNode' maxItems: 10000 additionalProperties: {} TipTapExtensionAttributes: type: object additionalProperties: {} securitySchemes: apiKey: type: http scheme: bearer ````