What is firefox-tab-manager?

A skill for managing the user’s live Firefox tabs and tab groups. It can open pages, find tabs, organize them, and verify that browser changes succeeded.

Use it to open or find Firefox tabs, collect pages into named groups, reorganize groups, or report what is currently open.

It reduces mistakes when an agent works with many browser tabs, especially when several tabs have similar names or addresses. It requires exact tab identification and verified results.

firefox-tab-manager — Skill for Codex by Johnnyzlee

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 Johnnyzlee/agent-bridge-for-tab-management-in-firefox --skill firefox-tab-manager

Clone the repo

git clone --depth 1 https://github.com/Johnnyzlee/agent-bridge-for-tab-management-in-firefox

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/johnnyzlee/agent-bridge-for-tab-management-in-firefox/firefox-tab-manager/github.svg)](https://agentmods.dev/skills/johnnyzlee/agent-bridge-for-tab-management-in-firefox/firefox-tab-manager)

Your own site

<a href="https://agentmods.dev/skills/johnnyzlee/agent-bridge-for-tab-management-in-firefox/firefox-tab-manager"><img src="https://agentmods.dev/badge/skills/johnnyzlee/agent-bridge-for-tab-management-in-firefox/firefox-tab-manager/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/johnnyzlee/agent-bridge-for-tab-management-in-firefox/firefox-tab-manager"><img src="https://agentmods.dev/badge/skills/johnnyzlee/agent-bridge-for-tab-management-in-firefox/firefox-tab-manager.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 87 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,777 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	$0.00087	$0.01777
Opus 5.5	$0.00035	$0.00711
Sonnet 5.5	$0.00017	$0.00355
Haiku 4.5	$0.00009	$0.00178

Measured 2mo ago against content hash ce27cc3e19eb, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

firefox-tab-manager 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.

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/firefox-tab-manager/SKILL.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Firefox Tab Manager

Operate the user's live Firefox tabs and native tab groups through the firefox-tabs MCP tools. The bridge is authenticated and local; treat only post-operation verified results as success.

When to use this skill

Use these tools whenever the request involves Firefox tabs or tab groups: opening pages, grouping links for later reading, reorganizing groups, finding a specific tab, or reporting what is open. Prefer them over coordinate-based or screenshot-driven browser automation.

Ground rules

Exact identity first. Select tabs by tabId when you have it (from list_firefox_tabs, open_firefox_tab, or get_active_firefox_tab). Otherwise use the complete URL or complete title. Never guess between multiple matches — the tools reject ambiguity; so should you.
Verify before reporting. Every write tool reads Firefox state back. Report only the verified tabId, windowId, groupId, and titles from the tool result. Never claim success without it.
Never fabricate. Do not invent tab IDs, group titles, or window IDs. Discover them first.
Confirm destructive actions. Closing tabs/groups, unpinning, and muting are user-visible changes. Confirm before acting when the user's intent is not explicit.

Opening pages and waiting for load

Check get_firefox_bridge_status when connection state is unknown.
Open a single page: open_firefox_tab with the explicit http:///https:// URL. Keep active: false unless the user asks to focus it.
Open a new window: new_firefox_window (optionally with a URL); it returns the verified windowId and first tab.
Open a batch into one group: open_firefox_tabs_into_group with urls + groupTitle. It creates the group only if missing and rolls back opened tabs on failure.
When the user needs to interact with the page right away, call wait_for_firefox_tab with the returned tabId; it returns instantly once the extension's load-completion event arrives (or times out with TAB_LOAD_TIMEOUT).

Read the full file on GitHub · 101 lines

Files

What ships with it

1 file 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.

agents/openai.yaml 506 B

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 · 101 lines · 87 tokens per session scan A ce27cc3e19eb

Subscribe to this mod's changes

firefox-tab-manager is a skill published in the GitHub repository Johnnyzlee/agent-bridge-for-tab-management-in-firefox (0 stars, last pushed 2mo ago), licensed MPL-2.0. It adds 87 tokens to every session and 1,777 once invoked, about $0.0003 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 2026-08-31.

Browser automation agent-skills browser-extension firefox mcp model-context-protocol tab-groups

firefox-tab-manager next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
firefox-tab-managerJohnnyzlee/agent-bridge-for-tab-management-in-firefox	Skill	0	2mo ago	MPL-2.0	A	87	Codex
Browser Extension TestingPramodDutta/qaskills	Skill	245	4d ago	MIT	A	29	Claude Code, Codex
playwright-climicrosoft/playwright	Skill	99k	today	Apache-2.0	A	19	Claude Code
playwright-component-testingmicrosoft/playwright	Skill	99k	today	Apache-2.0	A	69	Claude Code, Codex
chrome-extensionericrisco/rsc-harness	Skill	529	3d ago	MIT	A	76	Claude Code, Codex
codexless-browser-repairliyana31811/Codexless	Skill	125	17d ago	Apache-2.0	A	70	Claude Code, Codex
XSS_SKILLBugTraceAI/BugTraceAI-CLI	Skill	183	8d ago	Apache-2.0	A	11	Claude Code, Codex