# Addfox Best Practices

> Best practices for building browser extensions with the Addfox framework. Use when developing extensions with Addfox, configuring manifest/entry/permissions, or when discussing MV3, cross-browser support, framework/styling choices, messaging, and content UI injection.

- Skill: `addfox/addfox-best-practices` (Agent Skill, multi-file: 11 files)
- Install (CLI): `npx skillmds@latest add addfox/addfox-best-practices`
- Raw SKILL.md: https://api.skillmd.com/api/skills/addfox/addfox-best-practices/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: addfox (https://skillmd.com/u/addfox)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/addfox/addfox-best-practices

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# Addfox Best Practices

Use this skill when working on Addfox extension architecture, configuration, and runtime integration.

## When to use

Use this skill when you need to:
- Configure `addfox.config.ts` (`manifest`, `entry`, `plugins`, `rsbuild`, `appDir`, `outDir`)
- Design entry strategy for `background`, `content`, `popup`, `options`, and custom entries
- Decide permissions and host patterns for least-privilege access
- Target both Chromium and Firefox with browser-specific manifest sections
- Implement content UI and messaging between extension contexts

## Quick references

| Topic | See |
|---|---|
| Entry setup | [rules/entry.md](./rules/entry.md) |
| Chromium details | [rules/chromium.md](./rules/chromium.md) |
| Firefox details | [rules/firefox.md](./rules/firefox.md) |
| Manifest V3 | [rules/mv3.md](./rules/mv3.md) |
| Manifest V2 | [rules/mv2.md](./rules/mv2.md) |
| Manifest fields | [rules/manifest-fields.md](./rules/manifest-fields.md) |
| Permissions | [rules/permissions.md](./rules/permissions.md) |
| Content UI | [rules/content-ui.md](./rules/content-ui.md) |
| Messaging | [rules/messaging.md](./rules/messaging.md) |

## Best-practice checklist

- Prefer file-based reserved entries first; use `entry` only when customization is required.
- Keep manifest source paths clear and let Addfox resolve build output paths.
- Minimize permissions and host scope; avoid `<all_urls>` unless absolutely necessary.
- Keep background logic event-driven for MV3 service worker lifecycle.
- Use typed message contracts across contexts to reduce runtime mismatch.

## Related docs

- [reference.md](./reference.md)
- [rules/entry.md](./rules/entry.md)
- [rules/manifest-fields.md](./rules/manifest-fields.md)