caveman-browse

caveman-browse is a local browser-interaction MCP server. It attaches to Chrome, reads Accessibility.getFullAXTree, compresses the AX payload through the Caveman engine's forced-only a11y compressor, and exposes four tools:

• browser_snapshot
• browser_act
• browser_eval
• browser_recover

Savings are always inferred. Recovery is CCR-backed: browser_recover returns the byte-exact original AX payload for a snapshot handle.

Source and binaries ship under BSL 1.1. This runtime is source-available, not OSI Open Source before Change Date. First-party self-hosted production is permitted; third-party hosted, managed, or embedded use requires commercial license. See LICENSE and ../LICENSING.md.

browser_snapshot.query is the token-efficient path on large pages. It keeps best matching accessible nodes and ancestors while CCR retains full raw tree; compact output uses [uid] role "name" lines, with UID tokens reserved for actionable or unknown custom roles. tokens_after counts exact agent-visible JSON result, and view_tokens isolates compact tree cost.

Build:

go build ./browse/cmd/caveman-browse

Run as MCP server:

caveman-browse

Direct CLI helper:

caveman-browse snapshot http://127.0.0.1:3000
caveman-browse snapshot http://127.0.0.1:3000 "save settings"
caveman-browse act <uid> click
caveman-browse recover <handle>
caveman-browse close

Direct commands share one detached, isolated Chrome until close; first use creates profile and CCR directories. Actions report settled:false until another focused snapshot proves state, while navigation permits http(s), about:blank, and bounded data:text/html but rejects local files and privileged schemes.

Proof and comparison: BENCHMARK.md. Large-page query focus wins sharply; tiny-page results can exceed bare Playwright ARIA text because Caveman also returns UIDs, recovery, and exact accounting.