> ## Documentation Index > Fetch the complete documentation index at: https://docs.vocobase.com/llms.txt > Use this file to discover all available pages before exploring further. # Start a browser WebRTC session > Creates a browser voice session and returns a room URL plus a one-time access token your browser uses to connect to the agent in real time. The session is fully tracked on the platform — when the session ends, the same `session.completed` partner webhook fires (transcript, recording_url, extraction). The webhook payload's `call` field is omitted for these sessions because there is no associated phone call. See [Web Voice Testing](/web-voice-testing) for end-to-end browser integration code. **Auth + limits:** Bearer API key (`rg_live_*`). Bound by the API key's concurrency limit. Rate-limited to 10 starts/minute per key. ## OpenAPI ````yaml /openapi.json post /sessions/webrtc openapi: 3.1.0 info: title: Vocobase Partner API version: '2.0' description: >- API for managing voice AI agents, documents, and calls on the Vocobase platform. servers: - url: https://api.vocobase.com/api/v2 description: Production security: - bearerAuth: [] tags: - name: Config description: >- Read and update partner configuration, webhook settings, and telephony credentials. - name: Agents description: Create, read, update, and delete voice AI agents. - name: Voices description: >- List voice tiers, available voices, and stream preview audio for agent configuration. - name: Documents description: Upload, manage, and delete knowledge base documents. - name: Agent Documents description: Link and unlink documents to agents for knowledge base integration. - name: Calls description: Initiate outbound calls and view call history. - name: Phone Numbers description: >- Import DIDs, assign agents for inbound routing, and re-sync carrier Application bindings. - name: Inbound Routing Policies description: >- Define pre-answer routing decisions for inbound calls before AI sessions are created. - name: Telephony Connections description: Create, list, rename, and disconnect named V2 telephony connections. - name: VoiceLink Management description: Manage VoiceLink reseller clients, DID mapping, and readiness sync. - name: Projects description: Organize agents into projects. Every agent belongs to exactly one project. - name: Dictionaries description: Speech-recognition dictionary CRUD and agent attachment. - name: Sessions description: Browser-initiated WebRTC voice sessions for in-app voice agents. paths: /sessions/webrtc: post: tags: - Sessions summary: Start a browser WebRTC session description: >- Creates a browser voice session and returns a room URL plus a one-time access token your browser uses to connect to the agent in real time. The session is fully tracked on the platform — when the session ends, the same `session.completed` partner webhook fires (transcript, recording_url, extraction). The webhook payload's `call` field is omitted for these sessions because there is no associated phone call. See [Web Voice Testing](/web-voice-testing) for end-to-end browser integration code. **Auth + limits:** Bearer API key (`rg_live_*`). Bound by the API key's concurrency limit. Rate-limited to 10 starts/minute per key. operationId: startWebrtcSession requestBody: required: true content: application/json: schema: type: object required: - agent_id properties: agent_id: type: string format: uuid description: ID of the agent to use for this session. variables: type: object additionalProperties: type: string description: >- Pre-call variable values. Keys must match variable names declared on the agent (`Agent.variables`). Substituted into the agent's prompt and greeting via `{{name}}` placeholders. Echoed in the `session.completed` webhook for partner-side audit. Missing variables render as empty strings. example: callee_name: Sajal responses: '201': description: >- Session started successfully. Pass `daily_room_url` and `daily_token` to your WebRTC client. content: application/json: schema: type: object properties: success: type: boolean const: true data: type: object properties: session_id: type: string format: uuid agent_id: type: string format: uuid daily_room_url: type: string format: uri description: >- WebRTC room URL. Pass to `client.connect({ url, token })`. daily_token: type: string description: One-time WebRTC access token for the room. example: success: true data: session_id: s1234567-abcd-1234-abcd-123456789012 agent_id: a1234567-abcd-1234-abcd-123456789012 daily_room_url: https://voice-session.example.com/abc123 daily_token: eyJhbGciOi... '400': $ref: '#/components/responses/ValidationError' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' '429': description: Concurrency limit reached for this API key. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: CONCURRENCY_LIMIT_EXCEEDED message: >- Concurrency limit reached. Maximum simultaneous sessions exceeded. '500': $ref: '#/components/responses/InternalError' '502': description: Voice session temporarily unavailable. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: BOT_SERVER_UNAVAILABLE message: Voice session temporarily unavailable. Please try again. components: responses: ValidationError: description: Validation error in request body or parameters. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: VALIDATION_ERROR message: agent_name is required and must be max 50 characters Unauthorized: description: Missing or invalid API key. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: UNAUTHORIZED message: Invalid or missing API key NotFound: description: Resource not found. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: NOT_FOUND message: Resource not found InternalError: description: Unexpected server error. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: INTERNAL_ERROR message: An unexpected error occurred schemas: ErrorResponse: type: object properties: success: type: boolean const: false error: type: object properties: code: type: string message: type: string required: - code - message required: - success - error securitySchemes: bearerAuth: type: http scheme: bearer description: >- API key in format: `rg_live_xxxx`. Pass as a Bearer token in the Authorization header. ````