What is extension-publish?

A command guide for preparing a browser extension for submission to the Chrome Web Store or Firefox Add-ons.

Use it to validate an extension, build browser-specific packages, inspect the results, and get submission details.

It brings the manifest, permissions, icons, builds, and package checks into one store-readiness process.

extension-publish — Command by extensiondev

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.

agentmods

npx agentmods add commands/extensiondev/mcp/extension-publish

Clone the repo

git clone --depth 1 https://github.com/extensiondev/mcp

Per session 15 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 577 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

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	$0.00015	$0.00577
Opus 5	$0.00008	$0.00289
Sonnet 5	$0.00003	$0.00115
Haiku 4.5	$0.00002	$0.00058

Measured yesterday against content hash a6d3f33e4f24, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

extension-publish 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 yesterday.

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.

claude/commands/extension-publish.md · 63 lines

How it starts

The opening of the file, as written. The whole thing — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prepare the current extension for store submission. The user said: $ARGUMENTS

Parse arguments

Default to both (Chrome + Firefox). If the user specifies chrome or firefox, target only that store.

Steps

Validate the manifest If MCP tool extension_manifest_validate is available, use it with the target browsers. Otherwise, read src/manifest.json and check:
- Has name, version, description
- Has appropriate manifest_version for each target
- Permissions are minimal (no unnecessary permissions)
- Has icons (at least 16x16, 48x48, 128x128)

Build for each target browser

npx extension build --browser=chrome --zip
npx extension build --browser=firefox --zip

Inspect the builds If MCP tool extension_analyze is available, use it for each browser build. Check:
- Total size under 10MB (store limit)
- No source maps in production build
- Has manifest.json in dist
- Has icons
Report store readiness

Chrome Web Store
- Zip location: dist/chrome/<name>.zip
- Submit at: https://chrome.google.com/webstore/devconsole
- Checklist:
  - manifest_version: 3
  - Icons: 128x128 PNG
  - Description under 132 characters (for listing)
  - Screenshots: 1280x800 or 640x400
  - Privacy policy URL (if using sensitive permissions)
Firefox Add-ons (AMO)
- Zip location: dist/firefox/<name>.zip
- Submit at: https://addons.mozilla.org/developers/
- Checklist:
  - manifest_version: 2 (recommended for broadest compat) or 3
  - No Chrome-only APIs without polyfill
  - Source code zip if using a bundler: npx extension build --browser=firefox --zip --zip-source
  - AMO requires source code review for minified/bundled code
Flag issues that would cause store rejection:
- <all_urls> host permission without justification
- activeTab + scripting without clear use case
- Remote code loading (eval, Function constructor, remote scripts)
- Excessive permissions for the extension's functionality

Read the full file on GitHub · 63 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.

yesterday First seen · 63 lines · 15 tokens per session scan A a6d3f33e4f24

Subscribe to this mod's changes

extension-publish is a command published in the GitHub repository extensiondev/mcp (1 stars, last pushed 2d ago), licensed Apache-2.0. It adds 15 tokens to every session and 577 once invoked, about $0.0001 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 agents ai-agent browser-extension chrome-extension claude claude-code

extension-publish

Getting it into your agent

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Parse arguments

Steps

Chrome Web Store

Firefox Add-ons (AMO)

What this file has done since we first saw it

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