Unbrowse — one intent, one result

Unbrowse is a web harness, not a browser command catalog. The agent states the outcome; the harness chooses the cheapest trustworthy path and returns either the result or one executable recovery step.

Agent contract

1. For any web read, search, list, or retrieval, run unbrowse "<task>" --url <url>.
2. If next_step begins with unbrowse, run that command once, then retry step 1 once.

A typed ask or deny gate is not a command: surface it to the user and stop. Without either field, use only the matching fallback: unbrowse auth <login_url> for auth, or unbrowse capture --url <url> --intent "<task>" for a genuine miss.

1. If that retry fails, stop and report the blocker. Do not invent another route.

For mutations, act only when the user explicitly requested the change. Dry-run first and require an independently issued host approval before unsafe execution. An invoking agent cannot approve its own request:

unbrowse execute --skill ID --endpoint ID --dry-run
# then surface the typed approval gate to the host/user

Invisible harness lifecycle

Runtime status: passive capture, DAG compilation, local replay, durable route state,
independent-replay promotion, lifecycle-issued publish permits, and a central fail-closed
remote transport boundary are implemented. The canonical bare/get/MCP resolver persists
browser evidence, bypasses browser-derived snapshots for validation, and stays API-only after
promotion. Legacy operator/background paths that do not yet produce lifecycle proof remain
local/fail-closed. The index queue now uses interruption-safe typed durable jobs; capture,
validation, publish-job adoption and full SDK/operator convergence continue.

resolve → browse → observe → compile DAG → replay-validate → promote → publish → reuse

These are runtime stages, not steps for the agent to hand-drive:

• Cold run: when no trustworthy route exists, the capture engine drives the real site

(Obscura where supported, browser fallback otherwise). First-party XHR/fetch traffic is observed passively while the requested interaction proceeds.

• Compile: useful requests become a typed operation DAG: endpoint semantics, dependencies,

holes, response shapes, auth requirements, and side-effect class. Assets, secrets, raw payloads, and incidental traffic are excluded.

• Validation run: a captured route is replayed and checked against browser/page truth,

the requested intent, schema/cardinality, safety, freshness, and policy. A capture alone is not publication proof.

• Promotion: after successful replay, the local API route becomes the preferred path.

Later matching calls use the API instead of reopening the browser; drift or failed parity demotes the route and reopens discovery.

• Publication: a validated, reusable closure of the DAG is converted to the remote skill

format and published for other agents only after sanitization and contribution-policy gates. Private, sensitive, PII-bearing, destructive, or origin-forbidden routes stay local.

The intended steady state is: first interaction browses and learns; the next matching interaction proves replay; subsequent interactions are API-first and fast. The harness, not the calling agent, decides when evidence is sufficient to promote or publish.

Thin remote execution boundary

The remote service may rank shared routes, compile sanitized skills, and provision short-lived, origin-scoped egress capabilities. Origin requests still execute locally; the legacy remote TLS-terminating fetch is disabled by default because it could observe response bodies. The local client remains the capability holder for browser, origin, and credential access.

May cross the boundary: normalized intent-shape hashes, hole names/types (never filled values), sanitized route/DAG shape, opaque credential pointers, policy state, and compact attestations.

Must remain sealed: cookies, passwords, API keys, wallet secrets, raw HAR data, captured response bodies, and PII. Remote residential egress and policy-compliant rate-limit recovery use server-held credentials or scoped capability tokens; credentials are never returned to the agent or embedded in a published skill. Challenges requiring human action return a typed gate: Unbrowse does not solve CAPTCHAs. It does not bypass payment, authorization, robots, site-policy, or human-consent gates.

Agent decisions

• Read: always use the one-call front door.
• Login: use the visible auth handoff once; never ask for or print credentials.
• Miss: allow one capture/retry so the harness can learn.
• Mutation: dry-run and obtain the required approval.
• Payment, terms, CAPTCHA, or guarded publication: surface the gate; never infer consent.
• Wrong or stale data: report failure/feedback so the route is demoted; do not scrape around it.

Never

• Use curl, WebFetch, multi-URL loops, or hand-scraping as a fallback.
• Run go → snap → click for an ordinary read.
• Hand-run resolve → execute for an ordinary read.
• Choose browsers, profiles, proxies, credentials, or UNBROWSE_* flags.
• Retry a failed call repeatedly or ignore next_step.
• Pipe secrets or raw captures through shell post-processing.
• Publish a route merely because it was observed once.

Install

npm install -g unbrowse@latest && unbrowse setup

MCP hosts should use the default agent surface:

{
  "mcpServers": {
    "unbrowse": {
      "command": "npx",
      "args": ["-y", "unbrowse", "mcp"],
      "env": { "UNBROWSE_MCP_SURFACE": "agent" }
    }
  }
}

Default tools are get, auth, capture, feedback, status, and diagnose. Operator commands such as resolve, execute, go, snap, review, and publish are debugging and governance surfaces, not the agent happy path.

Source: https://github.com/unbrowse-ai/unbrowse · Operator docs: https://docs.unbrowse.ai