How do I install the Caveman Browse skill?

Run npx skillmds@latest add juliusbrussee/caveman-browse in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Caveman Browse safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Caveman Browse?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Caveman Browse free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Caveman Browse?

Julius Brussee (@juliusbrussee) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Caveman Browse by juliusbrussee — Agent Skill

Name: Caveman Browse
Author: Julius Brussee

Caveman Browse

Drive web pages through the caveman-browse MCP tools (browser_snapshot, browser_act, browser_eval, browser_recover). Use whenever interacting with a web page, dashboard, or form through caveman-browse — it teaches the snapshot→act→verify loop, query-first discipline on large pages, and when to recover exact bytes.

File contents

Driving pages with caveman-browse

Four tools. The loop is: snapshot → act on a uid → focused re-snapshot to prove the action settled → recover exact bytes only when compression hid something you need.

The loop

browser_snapshot(url, query?) returns a compact accessibility tree: [uid] role "name" = "value" {state} lines plus one trailing accounting line (caveman before=… after=… ratio=… basis=inferred handle=ccr_…). uids are your action handles. They are valid for the current snapshot generation only.
browser_act(action, uid, text?, option?) — click, type, select, scroll, wait. Non-wait actions return settled:false: that is CDP dispatch acknowledgement, NOT proof the app updated.
Prove settlement: re-run browser_snapshot with a query focused on the expected outcome (e.g. the success toast text, the new row). Never chain a second action on top of an unproven first one.
browser_recover(handle, query?) returns the byte-exact original AX payload for a snapshot handle (or BM25-narrowed sections with query). Use it when the compressed view seems to be missing something — never guess.

Token discipline

Large or unknown pages: pass query. browser_snapshot(url, query) keeps at most 12 best-matching nodes plus ancestors. On a 200-row dashboard that is ~98 tokens instead of ~12k. Phrase the query with the words you expect on the target control ("Save order ORD-0173", "Email Plan").
interactive: true keeps only uid-bearing lines plus placing ancestors — cheaper than a full snapshot, but it hides page text you may need to read. Use it when you already know the page and only need controls. It is never the default.
Full snapshot (no query) is for genuinely unknown task intent only.
After navigation, old uids are stale; a failed/uncompressed snapshot keeps the prior page's uid map and returns cave_browser_snapshot_uncompressed — do not act on uids after that error until a fresh snapshot succeeds.

Boundaries (fail closed, don't fight them)

Navigation allows http(s), about:blank, bounded data:text/html. file:, javascript:, and privileged Chrome schemes are denied.
Unknown uids/actions return cave_snake_code errors — re-snapshot instead of retrying blind.
Disabled controls are rejected; make the control enabled first (fill the form, dismiss the overlay).
Scope is same-origin, predictable controls. Cross-origin iframes appear as leaf nodes; OOPIF content, dialogs, downloads are out of scope — say so rather than looping.
browser_eval(expression) is the JS escape hatch for reading state the AX tree cannot express. Prefer snapshot queries first.
Every reported saving is inferred (offline BPE count). Never present these numbers as provider-verified.

---name: caveman-browsedescription: Drive web pages through the caveman-browse MCP tools (browser_snapshot, browser_act, browser_eval, browser_recover). Use whenever interacting with a web page, dashboard, or form through caveman-browse — it teaches the snapshot→act→verify loop, query-first discipline on large pages, and when to recover exact bytes.---# Driving pages with caveman-browseFour tools. The loop is: snapshot → act on a uid → focused re-snapshot to provethe action settled → recover exact bytes only when compression hid something youneed.## The loop1. **`browser_snapshot(url, query?)`** returns a compact accessibility tree: `[uid] role "name" = "value" {state}` lines plus one trailing accounting line (`caveman before=… after=… ratio=… basis=inferred handle=ccr_…`). uids are your action handles. They are valid for the current snapshot generation only.2. **`browser_act(action, uid, text?, option?)`** — `click`, `type`, `select`, `scroll`, `wait`. Non-wait actions return `settled:false`: that is CDP dispatch acknowledgement, NOT proof the app updated.3. **Prove settlement**: re-run `browser_snapshot` with a `query` focused on the expected outcome (e.g. the success toast text, the new row). Never chain a second action on top of an unproven first one.4. **`browser_recover(handle, query?)`** returns the byte-exact original AX payload for a snapshot handle (or BM25-narrowed sections with `query`). Use it when the compressed view seems to be missing something — never guess.## Token discipline- **Large or unknown pages: pass `query`.** `browser_snapshot(url, query)` keeps at most 12 best-matching nodes plus ancestors. On a 200-row dashboard that is ~98 tokens instead of ~12k. Phrase the query with the words you expect on the target control ("Save order ORD-0173", "Email Plan").- **`interactive: true`** keeps only uid-bearing lines plus placing ancestors — cheaper than a full snapshot, but it hides page text you may need to read. Use it when you already know the page and only need controls. It is never the default.- Full snapshot (no query) is for genuinely unknown task intent only.- After navigation, old uids are stale; a failed/uncompressed snapshot keeps the prior page's uid map and returns `cave_browser_snapshot_uncompressed` — do not act on uids after that error until a fresh snapshot succeeds.## Boundaries (fail closed, don't fight them)- Navigation allows `http(s)`, `about:blank`, bounded `data:text/html`. `file:`, `javascript:`, and privileged Chrome schemes are denied.- Unknown uids/actions return `cave_snake_code` errors — re-snapshot instead of retrying blind.- Disabled controls are rejected; make the control enabled first (fill the form, dismiss the overlay).- Scope is same-origin, predictable controls. Cross-origin iframes appear as leaf nodes; OOPIF content, dialogs, downloads are out of scope — say so rather than looping.- `browser_eval(expression)` is the JS escape hatch for reading state the AX tree cannot express. Prefer snapshot queries first.- Every reported saving is `inferred` (offline BPE count). Never present these numbers as provider-verified.

Frequently asked questions