> ## Documentation Index > Fetch the complete documentation index at: https://docs.brosbots.com/llms.txt > Use this file to discover all available pages before exploring further. # Call Through A Trigger > Place an outbound phone call through an agent's API trigger node; `trigger_id` is the trigger node's ID in the agent's flow. Existing integrations keep working; new ones should use `POST /agents/{agent_id}/calls`, which needs no trigger node and takes the agent's ID. Body: `phone_number` (E.164) and optional `initial_context`, side by side. The response's `workflow_run_id` is the conversation to read afterwards with `GET /agents/{agent_id}/conversations/{conversation_id}`. Errors: 401 bad key, 402 no credits, 403 key from another organization, outbound calling blocked or the number on the do-not-call list (`do_not_call: ...`), 404 trigger missing or inactive, 409 outside calling hours (08:00-21:00 recipient's time; `Retry-After` and `detail.retry_at` say when), 429 all outbound channels busy (`Retry-After` in seconds). ## OpenAPI ````yaml /api-reference/openapi.en.json post /api/v1/triggers/{trigger_id}/calls openapi: 3.1.0 info: title: Brosbots API description: > The public Brosbots REST API. Build and manage voice agents, run outbound campaigns, read calls and usage, and manage phone numbers, tools, knowledge bases and integrations. ## Authentication Every request must include your organization's API key in the `X-API-Key` header: ``` X-API-Key: bb_live_... ``` You create and revoke keys in the dashboard: click your account in the bottom-left corner of the sidebar, then **Brosbots API**. ## Base URL ``` https://app.brosbots.com/api/v1 ``` ## Conventions - Request and response bodies are JSON (`Content-Type: application/json`). - Timestamps are ISO 8601 with a timezone. - Lists are paginated with `page` / `limit` parameters; responses include `total_count` / `total_pages`. - Errors use standard HTTP status codes with a JSON body: `{"detail": "a human-readable reason"}`. - `{agent_id}` accepts the agent's public ID (`agent_...`) or its number. ## Limits There is no fixed per-key request-rate limit today. `429` comes from the calling endpoints (`POST /agents/{agent_id}/calls` and `POST /triggers/{trigger_id}/calls`) when every outbound channel is busy; its `Retry-After` header says how many seconds to wait. Handle `429` generally: wait as long as `Retry-After` says, or back off exponentially when it is absent. A request-rate limit may be introduced. version: 1.0.0 servers: [] security: - ApiKeyAuth: [] paths: /api/v1/triggers/{trigger_id}/calls: post: tags: - Agents & Calls summary: Call Through A Trigger description: >- Place an outbound phone call through an agent's API trigger node; `trigger_id` is the trigger node's ID in the agent's flow. Existing integrations keep working; new ones should use `POST /agents/{agent_id}/calls`, which needs no trigger node and takes the agent's ID. Body: `phone_number` (E.164) and optional `initial_context`, side by side. The response's `workflow_run_id` is the conversation to read afterwards with `GET /agents/{agent_id}/conversations/{conversation_id}`. Errors: 401 bad key, 402 no credits, 403 key from another organization, outbound calling blocked or the number on the do-not-call list (`do_not_call: ...`), 404 trigger missing or inactive, 409 outside calling hours (08:00-21:00 recipient's time; `Retry-After` and `detail.retry_at` say when), 429 all outbound channels busy (`Retry-After` in seconds). operationId: post_triggers_trigger_id_calls parameters: - name: trigger_id in: path required: true schema: type: string - name: X-API-Key in: header required: true schema: type: string requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/TriggerCallRequest' responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/TriggerCallResponse' '404': description: Not found '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' components: schemas: TriggerCallRequest: properties: phone_number: type: string description: Number to call, in E.164 format. examples: - '+48123456789' initial_context: anyOf: - additionalProperties: true type: object - type: 'null' description: >- Variables the agent can use as {{initial_context.}} in its prompts. A sibling of phone_number, not a wrapper around it. examples: - first_name: Anna type: object required: - phone_number title: TriggerCallRequest description: Request model for triggering a call via API TriggerCallResponse: properties: status: type: string workflow_run_id: type: integer workflow_run_name: type: string type: object required: - status - workflow_run_id - workflow_run_name title: TriggerCallResponse description: Response model for successful call initiation HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array type: object title: HTTPValidationError ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array msg: type: string type: type: string type: object required: - loc - msg - type title: ValidationError securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-Key description: >- Your organization's API key (account in the bottom-left of the dashboard → Brosbots API). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.