> ## Documentation Index > Fetch the complete documentation index at: https://agents-docs.hockeystack.com/llms.txt > Use this file to discover all available pages before exploring further. # Continue an existing conversation > Send a message in an existing conversation thread. The conversation must have been created via POST /deals/{dealId}/conversations. ## OpenAPI ````yaml https://app.hockeystack.com/api/revenue-agents/v1/openapi.json post /deals/{dealId}/conversations/{cid}/messages openapi: 3.1.0 info: title: HockeyStack Revenue Agents API version: v1 description: | Headless HTTP API for HockeyStack Revenue Agents. Auth: Bearer ApiToken (`hsr_live_`) in the Authorization header. contact: name: HockeyStack Support email: support@hockeystack.com servers: - url: https://app.hockeystack.com/api/revenue-agents/v1 description: Production security: - bearerAuth: [] tags: - name: Service description: Health checks and token introspection. - name: Agents description: Deal- and company-agent lifecycle. - name: Conversations description: > Send messages to a deal or company agent. Two transports: - **REST blocking (default):** request returns when the agent finishes. Response shape: `{ conversation_id, messages: [...] }`. - **SSE streaming:** opt in via `Accept: text/event-stream` header or `{ stream: true }` body field. Events emitted: - `text_delta { content }` — incremental assistant tokens - `tool_use { id, tool_name }` — agent is calling a tool - `tool_result { id }` — tool finished (return value not exposed in v1) - `done { conversation_id, messages }` — final state, same shape as REST response - `error { code, category, message }` — failure - name: Tasks description: | Agent-generated and manually-created tasks. Public status enum: `pending | completed | dismissed | cancelled`. Additional internal states are not exposed. - name: Credits description: | Workspace credit usage and limit state. There is no pre-paid balance pool to draw down — the model is a per-month usage counter against an included bundle plus an optional on-demand cap. Use these endpoints to detect approaching spend caps before hitting a 503. paths: /deals/{dealId}/conversations/{cid}/messages: parameters: - $ref: '#/components/parameters/DealId' - $ref: '#/components/parameters/ConversationId' post: tags: - Conversations summary: Continue an existing conversation description: | Send a message in an existing conversation thread. The conversation must have been created via POST /deals/{dealId}/conversations. operationId: sendDealMessage requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SendMessageBody' responses: '200': description: Assistant response. content: application/json: schema: $ref: '#/components/schemas/MessageResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' '409': description: Agent is currently initializing — retry after the indicated period. content: application/json: schema: $ref: '#/components/schemas/Error' '429': $ref: '#/components/responses/RateLimited' '500': description: Unexpected internal error. content: application/json: schema: $ref: '#/components/schemas/Error' '503': $ref: '#/components/responses/Unavailable' components: parameters: DealId: name: dealId in: path required: true description: CRM deal ID (HubSpot/Salesforce object ID). schema: type: string minLength: 1 maxLength: 64 ConversationId: name: cid in: path required: true description: >- Conversation ID returned by POST /deals/{dealId}/conversations (or the company equivalent). schema: type: string minLength: 1 maxLength: 128 schemas: SendMessageBody: type: object required: - message properties: message: type: string minLength: 1 maxLength: 10000 description: User message text. MessageResponse: type: object required: - conversation_id - messages properties: conversation_id: type: string description: >- Use this on subsequent POST /conversations/{cid}/messages calls to continue the thread. messages: type: array description: Messages produced by this turn (typically one assistant message). items: type: object required: - role - content properties: role: type: string enum: - assistant content: type: string Error: type: object required: - error properties: error: type: object required: - code - category - message - request_id properties: code: type: string description: Stable error code. Never renamed or removed within /v1. category: type: string enum: - permanent - transient - rate_limited description: | `permanent` — fix the request. `transient` — retry with backoff. `rate_limited` — retry after the Retry-After header. message: type: string description: Human-readable English message. Wording may change. request_id: type: string description: Trace ID for support tickets. Same as X-Request-Id header. details: type: object description: Code-specific structured data. responses: BadRequest: description: Validation failed. content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: Missing or invalid token. content: application/json: schema: $ref: '#/components/schemas/Error' examples: tokenMissing: value: error: code: auth.token_missing category: permanent message: 'Missing Authorization: Bearer header.' request_id: req_abc tokenInvalid: value: error: code: auth.token_invalid category: permanent message: API token is invalid, expired, or revoked. request_id: req_abc NotFound: description: Resource (deal, agent, conversation) does not exist. content: application/json: schema: $ref: '#/components/schemas/Error' RateLimited: description: Per-token or per-IP rate limit exceeded. headers: Retry-After: $ref: '#/components/headers/RetryAfter' X-RateLimit-Pool: $ref: '#/components/headers/RateLimitPool' X-RateLimit-Limit: $ref: '#/components/headers/RateLimitLimit' X-RateLimit-Remaining: $ref: '#/components/headers/RateLimitRemaining' X-RateLimit-Reset: $ref: '#/components/headers/RateLimitReset' content: application/json: schema: $ref: '#/components/schemas/Error' Unavailable: description: An upstream dependency is unavailable. content: application/json: schema: $ref: '#/components/schemas/Error' headers: RetryAfter: description: Seconds until retry is allowed. schema: type: integer RateLimitPool: description: Pool that consumed a point for this request (`read` or `write`). schema: type: string enum: - read - write RateLimitLimit: description: Maximum requests allowed in the current window for this pool. schema: type: integer RateLimitRemaining: description: Requests remaining in the current window. schema: type: integer RateLimitReset: description: Unix timestamp when the bucket refills. schema: type: integer securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: hsr_live ````