> ## Documentation Index > Fetch the complete documentation index at: https://docs.sigmamind.ai/llms.txt > Use this file to discover all available pages before exploring further. # Create Chat > Creates a new chat session with the specified agent and sends the initial message. Returns the agent’s reply along with the chatId for subsequent completion, update, and end-session calls. ## OpenAPI ````yaml post /v1/chats openapi: 3.0.1 info: title: SigmaMind APIs description: OpenAPI documentation SigmaMind Agent Builder APIs version: '1.0' servers: - url: https://api.sigmamind.ai description: SigmaMind AI Agent Builder APIs security: - apiKeyAuth: [] tags: - name: Chats description: >- Endpoints for creating and managing text-based chat sessions with an agent. A session is started by specifying an agent and an opening message. Returns a chatId used in all subsequent get, update, completion, and end-session calls. - name: Calls description: >- Endpoints for creating and managing outbound phone calls. A call is initiated by specifying an agent, caller number, and destination number — dynamic variables can be included to personalise the agent's behaviour. Returns a callId used in all subsequent get and delete operations. - name: Phone Numbers description: >- Endpoints for managing phone numbers used in outbound and inbound calls. Supports purchasing a new number through SigmaMind or importing an existing number via SIP trunking (BYO). Each number can be assigned separate inbound and outbound agents. - name: Campaigns description: >- Endpoints for creating and managing outbound call campaigns. A campaign dials a CSV-uploaded contact list using a selected agent and caller number, with support for immediate or scheduled launch. Returns a campaignId used in all subsequent get, update, and delete operations. - name: Agents description: >- Endpoints for creating and managing single prompt agents. An agent is configured with a system prompt, voice settings, and optional tools. Returns an agentId used in all subsequent update, call, and simulation operations. - name: Integrations description: >- Endpoints for creating and managing third-party integrations (e.g. Shopify, Cal.com). An integration links your account to an external service and acts as the parent resource for auth credentials and API tools. Returns an integrationId used in all subsequent auth and tool operations. - name: Integration Auth description: >- Endpoints for managing authentication credentials for a third-party integration. Supports API Key, Basic, and Bearer token credential types — scoped to an integration and injected automatically by tools when executing. Returns an authId used in all subsequent get, update, and delete operations. - name: Integration Tools description: >- Endpoints for creating and managing API tools backed by a third-party integration. Each tool defines an HTTP endpoint, method, and parameter schema — scoped to an integration and using its stored auth credentials when executing. Returns a toolId used in all subsequent get, update, delete, and execute operations. - name: Webhooks description: >- Endpoints for registering and managing webhooks. A webhook delivers real-time event notifications via HTTP POST when selected events occur on a specific agent — each webhook is scoped to one agent and one or more event types. Payloads are signed with an HMAC secret — verify the signature on your server to confirm authenticity. - name: Test Cases description: >- Endpoints for creating and managing simulation test cases for an agent. A test case defines a conversation scenario — including user persona, goals, and expected behaviour — used to generate a synthetic conversation with the agent. Returns a testCaseId used in all subsequent get, update, delete, and batch-run operations. - name: Batch Runs description: >- Endpoints for creating and managing batch runs of simulation test cases. A batch run executes multiple test cases in parallel against a selected agent and aggregates the results for review. Returns a batchId used in all subsequent get and list test-run operations. - name: Test Runs description: >- Endpoints for retrieving test run results within a batch. Each test run represents a single test case execution within a batch run, identified by a jobId. Use batchId and agentId to scope results to the correct batch. - name: API Keys description: >- Endpoints for creating and managing API keys used to authenticate public API requests. Each key must be included in the X-API-Key request header. Returns a keyId used in all subsequent get, revoke, and delete operations. - name: QA Rules description: >- Endpoints for creating and managing quality assurance rules applied to agent conversations. A QA rule defines evaluation criteria used to automatically assess conversation quality. Returns a qaRuleId used in all subsequent get, update, and delete operations. - name: QA Issues description: >- Endpoints for retrieving and managing quality assurance issues flagged across agent conversations. A QA issue is created with status 'Fail' when a conversation violates one or more QA rules — capturing the offending rule reference. It is created with status 'Success' when the conversation passes the evaluation criteria of QA rule(s). Returns a qaIssueId used in all subsequent get operations. paths: /v1/chats: post: tags: - Chats summary: Create Chat description: >- Creates a new chat session with the specified agent and sends the initial message. Returns the agent’s reply along with the chatId for subsequent completion, update, and end-session calls. operationId: createChat requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateChatRequest' required: true responses: '201': description: Created content: application/json: schema: $ref: '#/components/schemas/ChatCompletionResponse' '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/Error' examples: default: value: error: Bad Request message: Invalid request parameters path: /v1/chats status: 400 timestamp: '2026-05-05T10:06:43.615Z' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/Error' examples: default: value: error: Unauthorized message: X-API-Key is missing or invalid path: /v1/chats status: 401 timestamp: '2026-05-05T10:06:43.615Z' '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/Error' examples: default: value: error: Forbidden message: Access denied for this resource path: /v1/chats status: 403 timestamp: '2026-05-05T10:06:43.615Z' '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/Error' examples: default: value: error: Not Found message: The requested resource was not found path: /v1/chats status: 404 timestamp: '2026-05-05T10:06:43.615Z' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/Error' examples: default: value: error: Internal Server Error message: Unexpected server error path: /v1/chats status: 500 timestamp: '2026-05-05T10:06:43.615Z' components: schemas: CreateChatRequest: required: - agentId - input type: object properties: agentId: maxLength: 64 minLength: 1 type: string description: >- The unique identifier of the Agent assigned to handle the chat completion. example: D5D0p7TUs66TTAEAx input: maxLength: 20480 minLength: 1 type: string description: Input message from the customer or conversation history. example: Where is my order? dynamicVariables: type: object description: >- Dynamic key-value pairs required by the selected Agent for personalisation (e.g. customer name, account details). example: customer_name: Michael additionalProperties: oneOf: - type: string - type: number - type: boolean - type: object - type: array previousChatId: maxLength: 128 minLength: 0 type: string description: >- Unique ID of a previous chat session to use as context for this chat. example: chat_D5D0p7TUs66TTAEAx ChatCompletionResponse: type: object properties: chatId: type: string description: Unique identity for a chat example: chat_d17T6uReChpyfFeP createdAt: type: string description: The timestamp when the call record was created. format: date-time example: '2021-04-20T10:00:00.000Z' status: type: string description: Status of the chat example: ended enum: - in_progress - ended - error response: type: array description: Agent response of the last user message example: - id: item_G9YdhDqua0EngI1G role: assistant type: message content: - >- Hello! My name is Grace, and I'm calling on behalf of SigmaMind AI. Am I speaking with Michael? items: $ref: '#/components/schemas/ChatMessage' agent: $ref: '#/components/schemas/AgentResponse' Error: type: object properties: timestamp: type: string description: Error timestamp in ISO format format: date-time status: type: integer description: HTTP status code example: 400 error: type: string description: Error type or HTTP status message example: Bad Request message: type: string description: Detailed error message example: Email is required path: type: string description: Request path where error occurred example: /v1/users validationErrors: type: object description: Field validation errors (if any) example: |- { "email": "Email is required", "name": "Name is too short" } description: Standard error response ChatMessage: type: object properties: id: type: string description: Unique identity for a chat message example: item_d17T6uReChpyfFeP role: type: string description: Role of the chat message example: user enum: - user - assistant type: type: string description: Type of the chat message example: message enum: - message content: type: array description: Chat message content example: >- Hello! My name is Grace, and I'm calling on behalf of SigmaMind AI. Am I speaking with Michael? items: type: string description: Chat message content example: >- Hello! My name is Grace, and I'm calling on behalf of SigmaMind AI. Am I speaking with Michael? description: Agent response of the last user message example: - id: item_G9YdhDqua0EngI1G role: assistant type: message content: - >- Hello! My name is Grace, and I'm calling on behalf of SigmaMind AI. Am I speaking with Michael? AgentResponse: type: object properties: name: type: string description: The display name of the assigned agent. example: New AI Agent agentId: type: string description: The unique identifier of the agent within the system. example: agent_D5D0p7TUs66TTAEAx status: type: string description: The current operational status of the agent. example: Live enum: - Live - Testing - Disabled description: >- Agent assigned to handle all calls in this campaign. Contains the agent's ID, name, and current status. All contacts in the campaign's contact list will be called using this agent. securitySchemes: apiKeyAuth: type: apiKey description: >- Authenticate every request by passing your API key in the `X-API-Key` header. To get your key, go to Dashboard → API Keys and create or copy your Production API key. name: X-API-Key in: header ````