Create a standalone browser session
Create a standalone browser session the user can log into interactively (no task thread required).
Sessions are cloud by default (Kernel: stealth and captcha support on
by default, resource-scoped profile persistence for captured auth) —
many concurrent sessions without sizing up the sandbox — falling back
to sandbox-local Chrome when cloud is unavailable. The
user’s default sandbox is resolved (auto-starting it if needed), a
pinned agent-browser daemon is attached there, and a redacted manifest
with createdBy: "ui" is written to the sandbox task directory. The
returned sessionRef can later be referenced from a task so the agent
reuses the warm, logged-in browser.
Only opaque references and redacted metadata are returned — never transport URLs, API keys, cookies, or auth headers.
Authorizations
JWT authentication token
Query Parameters
Optional project ID to create the session on the project sandbox (requires membership)
Body
Optional user-assigned display name, persisted in the manifest.
"MetaMask login"
Optional initial URL to open after launch (e.g. a login page). Defaults to about:blank.
"https://example.com/login"
Response
The created browser session manifest
'cloud' (Kernel/Browserbase) or 'local' (sandbox).
"cloud"
Opaque Neo-issued reference (brs_) exposed to UI/agents.
"brs_0f1e2d3c4b5a69788796a5b4"
Lifecycle status: 'active', 'closed', or 'error'.
"active"
Task thread this session belongs to.
Sandbox directory for session artifacts (e.g. screenshots).
Open tabs captured from the live session, used to restore the working set when a cloud session resumes to about:blank. Sandbox-resident only.
ISO timestamp when the session was first created.
'agent' or 'ui'.
'chrome' or 'lightpanda' (local only).
"chrome"
User-assigned display name for UI-created sessions.
"MetaMask login"
ISO timestamp the session was last attached/resumed.
ISO timestamp the tab set was last captured.
Sandbox-relative manifest path (audit/debug; no secrets).
Reusable profile reference; absent for ephemeral/isolated sessions.
Manifest schema version.
Full initial URL a UI session was created with (UI sessions only).
"https://app.uniswap.org"
ISO timestamp when the manifest was last written.
Owning user id.

