> ## Documentation Index
> Fetch the complete documentation index at: https://docs-dev.setoo.work/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Start web call

> Open a browser-based voice session with an agent and get WebRTC connection details

Creates a live web-call session so a user can talk to a voice agent directly in
the browser — no phone number involved. The response carries the WebRTC
connection details your frontend needs to join the session.

### Body parameters

<ParamField body="agentId" type="string" required>
  UUID of a VOICE-capable agent to talk to
</ParamField>

<CodeGroup>
  ```bash curl theme={null}
  curl -X POST https://api.agentic-os.com/api/v1/channels/web/session \
    -H "Authorization: Bearer $AGENTIC_OS_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{ "agentId": "AGENT_ID" }'
  ```

  ```python Python theme={null}
  requests.post(
      "https://api.agentic-os.com/api/v1/channels/web/session",
      headers={"Authorization": f"Bearer {API_KEY}"},
      json={"agentId": "AGENT_ID"},
  )
  ```

  ```javascript Node theme={null}
  await fetch("https://api.agentic-os.com/api/v1/channels/web/session", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ agentId: "AGENT_ID" }),
  });
  ```
</CodeGroup>

### Response

Returns the session identifier plus the connection details for the browser
client. Shape varies with the configured voice provider.

<Callout type="warning">
  A web call consumes wallet balance for as long as it stays open, the same way a
  phone call does.
</Callout>