Use it when developing or maintaining the Firefox tab-management toolkit, including its browser extension, local server, and native messaging components.

It gives coding agents the project context and rules they need before changing the repository. This helps them work in the correct files and follow the project’s conventions.

How Johnnyzlee/agent-bridge-for-tab-management-in-firefox configures C

Q: What is agent-bridge-for-tab-management-in-firefox AGENTS.md?

A set of project instructions for developing a toolkit that lets AI agents manage Firefox tabs and native tab groups. It documents the project layout, commands, and coding rules.

Reuse

Borrowing it

Nothing to install: this file belongs to Johnnyzlee/agent-bridge-for-tab-management-in-firefox. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/Johnnyzlee/agent-bridge-for-tab-management-in-firefox/main/AGENTS.md

Clone the repo

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

Made for: Codex, OpenCode.

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

Your own site

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

Per session 1,451 This file is loaded in full into every session.

When invoked 1,451 The same file — it is already loaded in full.

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	$0.01451	$0.01451
Opus 5	$0.00726	$0.00726
Sonnet 5	$0.00290	$0.00290
Haiku 4.5	$0.00145	$0.00145

Measured 10d ago against content hash 50f4e611e3d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

agent-bridge-for-tab-management-in-firefox AGENTS.md 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 10d 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.

AGENTS.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Project conventions and workflows for agents working in this repository. Read this before any task; follow it unless the user explicitly says otherwise.

What this is

Agent Bridge for Tab Management in Firefox — a local-first toolkit letting AI agents manage the user's live Firefox tabs and native tab groups. TS + Node 20+, MPL-2.0. Latest release: v0.5.7 (25 MCP tools). Extension Gecko ID: [email protected] — never change it.

Project structure

extension/ — Firefox WebExtension. background.ts is the only bundled entry (esbuild → dist/firefox-extension/background.js); controller.ts holds every browser operation (tabs + tabGroups APIs); manifest.json, options.* are copied as-is.
mcp-server/ — MCP server. index.ts is the CLI entry (subcommands setup/doctor/uninstall, default starts the stdio server). broker.ts is the shared broker (extension port + agent port, multi-client routing, event-driven wait_tab); client.ts is the agent-side connection used when another broker already owns the ports. mcp.ts registers the MCP tools.
native-host/ — Native Messaging Host (length-prefixed JSON framing; serves bridge.json config to the extension).
shared/ — protocol.ts (bridge wire protocol), config.ts (user-level config paths, token, native-host manifests), errors.ts (FirefoxTabsError).
cli/commands.ts — setup/doctor/uninstall logic shared with the MCP entry.
tests/ — Vitest; controller.test.ts and broker.test.ts carry most coverage.
scripts/upgrade.sh — user-facing auto-upgrade (pull → rebuild → restart Hermes → open signed XPI → sync skill).

Commands

npm run check        # REQUIRED before every commit: typecheck + vitest + build + web-ext lint
npm run build        # rebuild dist/ (server, native host, extension)
npm run setup        # local pairing (config + Native Host registration)
npm run doctor       # health check (config, permissions, host registration)
npm test             # vitest only
npm pack --dry-run   # verify the npm package contents

Read the full file on GitHub · 75 lines

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.

10d ago First seen · 75 lines · 1,451 tokens per session scan A 50f4e611e3d0

Subscribe to this mod's changes

agent-bridge-for-tab-management-in-firefox AGENTS.md is an instructions file published in the GitHub repository Johnnyzlee/agent-bridge-for-tab-management-in-firefox (0 stars, last pushed 23d ago), licensed MPL-2.0. It adds 1,451 tokens to every session, about $0.0073 per session on Opus 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

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Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

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