What is tabbit-devtools?

Instructions for connecting the Tabbit Chromium browser to agent-browser through its live DevTools connection. DevTools is the browser interface that lets another program inspect and control an open browser.

Use it to discover Tabbit’s connection endpoint and then open pages, inspect them, click controls, fill fields, and press keys through agent-browser.

It gives browser automation a way to use the existing Tabbit session instead of opening a separate browser or building a custom connection.

tabbit-devtools — Skill for Codex by Tabbit-Browser

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add Tabbit-Browser/Tabbit-Devtools-Skill --skill tabbit-devtools

Clone the repo

git clone --depth 1 https://github.com/Tabbit-Browser/Tabbit-Devtools-Skill

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/tabbit-browser/tabbit-devtools-skill/tabbit-devtools/github.svg)](https://agentmods.dev/skills/tabbit-browser/tabbit-devtools-skill/tabbit-devtools)

Your own site

<a href="https://agentmods.dev/skills/tabbit-browser/tabbit-devtools-skill/tabbit-devtools"><img src="https://agentmods.dev/badge/skills/tabbit-browser/tabbit-devtools-skill/tabbit-devtools/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/tabbit-browser/tabbit-devtools-skill/tabbit-devtools"><img src="https://agentmods.dev/badge/skills/tabbit-browser/tabbit-devtools-skill/tabbit-devtools.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 40 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,150 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00040	$0.01150
Opus 5.5	$0.00016	$0.00460
Sonnet 5.5	$0.00008	$0.00230
Haiku 4.5	$0.00004	$0.00115

Measured 2mo ago against content hash 839e370c2995, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

tabbit-devtools scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

The scan reads SKILL.md. This mod also ships 3 executable files (scripts/discover_tabbit_cdp.py, scripts/read_current_tabbit_page.py, scripts/run_agent_browser_on_tabbit.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/tabbit-devtools/SKILL.md · 78 lines

How it starts

The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Tabbit Devtools

Prefer this skill whenever the request is explicitly about Tabbit or includes phrases like 用我的 tabbit 浏览器, 在 Tabbit 里, Tabbit 当前页, or Tabbit 当前标签.

Treat Tabbit as a Chromium-based browser. This skill is about how to connect agent-browser to Tabbit. After the connection is established, handle browser automation and inspection through the normal agent-browser workflow. Do not implement a parallel browser automation layer, bridge daemon, or custom CDP client inside this skill.

agent-browser Quick Reference

Treat agent-browser as the browser-operation layer after Tabbit endpoint discovery.

The most relevant commands for this skill are:

open <url>
snapshot -i
click @e3
fill @e5 <text>
press Enter

Do not restate a full agent-browser manual here. Use these commands as the default vocabulary for Tabbit tasks, and prefer the official README for any broader command surface.

Quick Path

Detect the platform and search for DevToolsActivePort:
- macOS: ~/Library/Application Support/Tabbit/DevToolsActivePort first, then ~/Library/Application Support/Tabbit Browser/DevToolsActivePort
- Windows: %LOCALAPPDATA%\Tabbit Browser\User Data\DevToolsActivePort first, then %APPDATA%\Tabbit\User Data\DevToolsActivePort
Use both lines in that file:
- line 1: TCP port
- line 2: browser path such as /devtools/browser/<id>
Build the full browser endpoint as ws://127.0.0.1:<port><path>.
Prefer that wsEndpoint over http://127.0.0.1:<port>. Tabbit may expose the browser WebSocket while /json/version and /json/list still return 404.
Prefer scripts/run_agent_browser_on_tabbit.py for actual browser actions. It injects the live wsEndpoint into agent-browser --cdp ....
Use scripts/discover_tabbit_cdp.py when you only need structured connection facts.
Once connected, use the full normal agent-browser workflow for page operations.

Read the full file on GitHub · 78 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 78 lines · 40 tokens per session scan A 839e370c2995

Subscribe to this mod's changes

tabbit-devtools is a skill published in the GitHub repository Tabbit-Browser/Tabbit-Devtools-Skill (47 stars, last pushed 5mo ago), licensed MIT. It adds 40 tokens to every session and 1,150 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Browser automation

tabbit-devtools next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
tabbit-devtoolsTabbit-Browser/Tabbit-Devtools-Skill	Skill	47	5mo ago	MIT	A	40	Codex
interactive-loginyc-software/qm	Skill	16k	yesterday	MIT	A	46	Claude Code, Codex
pinchtab-mcppinchtab/pinchtab	Skill	11k	10d ago	MIT	A	52	Claude Code, Codex
azure-messaging-webpubsub-javamicrosoft/skills	Skill	3.2k	yesterday	MIT	A	43	Claude Code
cua-driverdavidondrej/skills	Skill	4.3k	3d ago	MIT	A	68	Claude Code, Codex
open-design-browsercompozy/compozy	Skill	2.8k	yesterday	MIT	A	56	Claude Code, Codex
southwestborski/travel-hacking-toolkit	Skill	895	yesterday	MIT	A	40	Claude Code