---
title: "Open the API session browser"
method: POST
path: "/chat-sessions/{sessionId}/browser/open"
tags: ["Chat sessions"]
---

# Open the API session browser

`POST /chat-sessions/{sessionId}/browser/open`

Same-user, API-origin session browser operation. sessionId is the public chatSessions id. Screenshot evidence is returned as URLs; browser identity persists across turns.

## Path parameters

- `sessionId` string, required

## Request body

- object
  - `policy` BrowserToolPolicy
    - `mode` 'allow_all' | 'read_only' | 'allowlist', required
    - `originAllowlist` string[]
    - `toolAllowlist` string[]
  - `profileId` string

## Response `200`

Session browser result. Unknown command outcomes must be inspected before retrying with a different command ID.

- SessionBrowserOpened
  - `sessionId` string, required
  - `chatSessionId` string, required
  - `projectId` string, required
  - `browser` SessionBrowser, required
    - `browserSessionId` string, required
    - `state` 'active' | 'sleeping' | 'closed', required
    - `policy` BrowserToolPolicy
      - `mode` 'allow_all' | 'read_only' | 'allowlist', required
      - `originAllowlist` string[]
      - `toolAllowlist` string[]
    - `profileId` string
    - `bootId` string
    - `controlledBy` 'human' | 'null', nullable
    - `box` string, nullable
    - `lastActiveAt` number

## Other responses

- `400` — Invalid request or policy
- `401` — Authentication required
- `403` — Access denied
- `404` — Session not found or not owned by caller
- `409` — Session closed or conflicting command ID
- `429` — Rate limited
- `502` — Browser control plane unavailable

## Changes

- **2026-09-10** `b4b7857c1379` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/mcpjam/apis/mcpjam-api/changes/chat-sessions/:sessionId/browser/open/post.md)

---

[API](https://skmtc.dev/mcpjam/apis/mcpjam-api.md) · [All operations](https://skmtc.dev/mcpjam/apis/mcpjam-api/llms.txt) · [OpenAPI document](https://skmtc.dev/mcpjam/apis/mcpjam-api/revisions/56b9d1dda7ea?raw)