What is Pi Jev Browser?

A browser and macOS desktop agent extension for pi: Jev chooses each action from a structured observation — visible text plus addressable controls, never a screenshot — inside a bounded loop that knows when it is stuck or when the page moved underneath it.

How does it drive the browser?

Seven of the eight tools drive an isolated Playwright Chromium. Automatic operations are click, replace text, native dropdown selection, page scroll and short loading waits.

What is the jev_desktop tool?

It is the eighth tool: it drives one macOS application through its accessibility tree with the same loop and the same guards. src/loop.ts depends on a Driver and imports no Playwright, so browser, desktop and an in-memory test driver are interchangeable.

Run pi install npm:pi-jev-browser; pi installs the package under ~/.pi/agent/npm/ and pulls in playwright and @typesafe-ai/sdk, while Playwright downloads Chromium (~150 MB). You can also install from a pinned git tag or a local checkout.

What credentials does it need?

A TypeSafe API key from console.typesafe.ai, given as TYPESAFE_API_KEY or typesafe.apiKey in pi-jev-browser.config.json (chmod 600). jev_run resolves the key before Chromium starts, so a missing key fails with the file and variable to set.

What are the run limits?

Runs default to 20 steps with a maximum of 60 and a 100-second deadline. There is no default probability cutoff; an optional minProbability gates the selected choice's calibrated probability, which the README stresses is not provider confidence.

Is there a benchmark or a predecessor?

Both: benchmarks/README.md documents a 22-scenario capability suite across four tiers with measured results, and the project was ported from the Cline plugin, with every difference listed in docs/reference.md.

Jev directory

CommunityJev Agents & MCP

Pi Jev Browser

A browser and macOS desktop agent for pi: Jev picks each action from structured observations of visible text and addressable controls — never screenshots — inside a bounded loop that stops when stuck or hands control back to a human.

See highlights Open github.com

Stars: 1
Language: TypeScript
License: APACHE-2.0
Reading time: 2 min
Published by: Community
Author: laihenyi
Last verified: Oct 2026

laihenyi/pi-jev-browser

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Browser and macOS desktop agent for pi: Jev (TypeSafe System One) chooses each action from a structured observation in a bounded, surface-agnostic loop. Isolated Playwright tools, an allow-listed accessibility-tree tool, deterministic selectors, four-tier benchmarks.

Forks: 2
Last pushed: Updated Sep 2026

Repo stats from the GitHub API, cached Oct 2026.

Tagscommunity catalog-import logicrw browser-automation accessibility

Works forJev for Realtime control Jev for Tool calling

Used inJev for Software & DevTools

Languages: TypeScript
Platforms: Playwright macOS CLI
Capabilities: Open sourceRequires API key

Highlights

Seven of eight tools drive an isolated Playwright Chromium; the eighth, jev_desktop, drives one macOS app through its accessibility tree with the same guards.
src/loop.ts depends on a Driver and imports no Playwright, so the browser, the desktop and an in-memory test driver are interchangeable.
Runs default to 20 steps (maximum 60) with a 100-second deadline; optional minProbability gates the chosen answer's calibrated probability, not confidence.
Needs a TypeSafe key via TYPESAFE_API_KEY or typesafe.apiKey in pi-jev-browser.config.json; a missing key fails before Chromium starts.
A 22-scenario capability suite across four tiers measures the loop; automatic operations are click, replace text, native dropdown, scroll and short waits.

Quickstart

bash

pi install npm:pi-jev-browser
export TYPESAFE_API_KEY=...

Watch out

Copy reviewed against the truncated README on 2026-10-15; the final section cuts off mid-sentence. Install pulls in Chromium (~150 MB), and the 22-scenario suite's measured results were not reproduced here.

Questions about this entry

Short answers drawn from the linked project or page.

From the Jev guides

Original write-ups on what this entry is for.

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Read article

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Oct 16, 2026

How the Jev guard family turns coding-agent permissions into auto-approve, deny, or ask: hooks that enforce, guards that fail safe, and gateways that gate generation.

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