> ## Documentation Index > Fetch the complete documentation index at: https://docs.sendora.ai/llms.txt > Use this file to discover all available pages before exploring further. # Start widget call > Mint a browser WebRTC call for this widget's agent. Order: resolve + origin-check the widget, validate the pre-call form, upsert a lead if phone/email was collected, check tenant budget + daily cap, atomically reserve a concurrency slot, THEN mint the voice service call - never spend vendor minutes before every guard has passed. This operation can change workspace data or trigger an external side effect; review the request before sending it and do not retry blindly after a timeout. ## OpenAPI ````yaml /openapi.json post /api/v1/public/widget/{widget_public_id}/calls openapi: 3.1.0 info: description: >- Customer-facing API for managing outreach, leads, conversations, voice agents, knowledge bases, analytics, and webhooks. title: Sendora Public API version: 1.0.0 servers: - description: Production url: https://api.sendora.ai security: [] tags: - description: Build, launch, pause and stop campaigns, and enroll leads. name: Campaigns - description: Create, update, tag, enrich and import leads. name: Leads - description: Group leads into reusable lists. name: Lead lists - description: Find new prospects and research existing leads. name: Prospecting - description: Read conversations and send messages to leads. name: Inbox - description: Manage workspace-wide suppressions. name: Do not contact - description: Manage the content your agents answer from. name: Knowledge bases - description: Create, configure, test and publish voice agents. name: Voice agents - description: Give agents actions such as booking, lookups and transfers. name: Agent tools - description: Embed a voice agent on your website. name: Voice widgets - description: Start voice calls and read call results. name: Calls - description: Browse and preview the voices an agent can use. name: Voices - description: List numbers, bring your own, and route calls. name: Phone numbers - description: List the channel accounts connected to the workspace. name: Connected accounts - description: Register endpoints and review deliveries. name: Webhooks - description: Drive the workspace assistant programmatically. name: Copilot - description: Read workspace and campaign performance. name: Analytics - description: Track asynchronous operations. name: Jobs - description: Manage client workspaces, plans and branding. name: Agency paths: /api/v1/public/widget/{widget_public_id}/calls: post: tags: - Voice widgets summary: Start widget call description: >- Mint a browser WebRTC call for this widget's agent. Order: resolve + origin-check the widget, validate the pre-call form, upsert a lead if phone/email was collected, check tenant budget + daily cap, atomically reserve a concurrency slot, THEN mint the voice service call - never spend vendor minutes before every guard has passed. This operation can change workspace data or trigger an external side effect; review the request before sending it and do not retry blindly after a timeout. operationId: start_widget_call_api_v1_public_widget__widget_public_id__calls_post parameters: - description: >- The widget's public id, taken from its embed code (Get widget embed code). in: path name: widget_public_id required: true schema: title: Widget Public Id type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/PreCallFormPayload' required: true responses: '201': content: application/json: schema: $ref: '#/components/schemas/StartCallOut' description: Successful Response '402': description: The workspace is not currently eligible for this billable operation. '403': description: >- The key is valid but the workspace lacks the required entitlement, or a widget origin is not allowed. '404': description: >- The resource does not exist or is not owned by the authenticated workspace. '422': content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' description: Validation Error '429': description: The operation is rate limited. Respect Retry-After before retrying. '500': description: >- An unexpected Sendora error occurred. Retry only if the operation is safe to repeat. '503': description: >- The operation is temporarily unavailable. Retry with backoff when safe. security: [] x-codeSamples: - label: cURL lang: bash source: >- curl -X POST 'https://api.sendora.ai/api/v1/public/widget/YOUR_ID/calls' -H "Content-Type: application/json" \ -d '{"consent_accepted":true,"fields":{},"metadata":{}}' - label: Python lang: python source: >- import requests url = 'https://api.sendora.ai/api/v1/public/widget/YOUR_ID/calls' headers = {} response = requests.post(url, headers=headers, json={'consent_accepted': True, 'fields': {}, 'metadata': {}}) response.raise_for_status() print(response.json()) - label: JavaScript lang: javascript source: >- const response = await fetch("https://api.sendora.ai/api/v1/public/widget/YOUR_ID/calls", { method: "POST", headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({"consent_accepted": true, "fields": {}, "metadata": {}}), }); if (!response.ok) throw new Error(await response.text()); console.log(await response.json()); - label: Go lang: go source: >- req, err := http.NewRequest("POST", "https://api.sendora.ai/api/v1/public/widget/YOUR_ID/calls", bytes.NewBufferString(`{"consent_accepted": true, "fields": {}, "metadata": {}}`)) if err != nil { log.Fatal(err) } req.Header.Set("Content-Type", "application/json") resp, err := http.DefaultClient.Do(req) if err != nil { log.Fatal(err) } defer resp.Body.Close() components: schemas: PreCallFormPayload: properties: consent_accepted: default: false description: Consent accepted returned by the Sendora API. title: Consent Accepted type: boolean fields: additionalProperties: type: string description: Fields returned by the Sendora API. title: Fields type: object metadata: additionalProperties: type: string description: Metadata returned by the Sendora API. title: Metadata type: object required: [] title: PreCallFormPayload type: object StartCallOut: properties: call_id: description: The id of the call that was started, used by the widget to join it. title: Call Id type: string join_url: description: Join url returned by the Sendora API. title: Join Url type: string lead_capture_status: default: not_captured description: Lead capture status returned by the Sendora API. enum: - captured - not_captured - failed title: Lead Capture Status type: string required: - join_url - call_id title: StartCallOut type: object HTTPValidationError: properties: detail: description: Detail returned by the Sendora API. items: $ref: '#/components/schemas/ValidationError' title: Detail type: array required: [] title: HTTPValidationError type: object ValidationError: properties: loc: description: Loc returned by the Sendora API. items: anyOf: - type: string - type: integer title: Location type: array msg: description: Msg returned by the Sendora API. title: Message type: string type: description: Type returned by the Sendora API. title: Error Type type: string required: - loc - msg - type title: ValidationError type: object ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.