01
BlockMap first
Pages return an agent-shaped map of structure, headings, links, buttons, forms, and density instead of flooding the context with raw DOM.
Open-source browser tier
Web access for agents. No Chrome tax.
unbrowser is a lightweight MCP browser for LLM agents: one native binary, stateful sessions, bounded JavaScript, forms, cookies, and low-token BlockMaps before you escalate to a full Unchained Chrome session.
02
Stateful enough
Navigate, query, click, type, submit forms, run bounded JS, and carry cookies through a session without launching Playwright or Chrome.
03
Escalation ready
When a site needs real browser fidelity, auth, extensions, or human-in-the-loop control, hand off to Unchained instead of pretending a tiny runtime is Chrome.
Live fixed-source scan
Try the cheap pass before Chrome.
Choose a public source set. No arbitrary URLs are accepted. Every run launches live unbrowser navigate fetches for the fixed URLs, streams each result with a retrieval time, flags hard pages, and avoids cached replay data.
Sources0
Fetched0
Hard pages0
Facts0
Scan brief
{
"mcpServers": {
"unchained": {
"command": "unbrowser",
"args": ["--mcp"]
},
"unbrowser-hosted": {
"url": "https://unchainedsky.com/unbrowser-mcp"
}
}
}
Use the hosted endpoint only for public checks.
The hosted Streamable HTTP MCP endpoint is shared infrastructure for directory scanners, Smithery, Glama, and quick public-page smoke tests.
Do not send private cookies, secrets, or authenticated browsing tasks through it. Install the local binary for production workflows.