Extensions are plain files (manifest, scripts) you load locally, so an editor or terminal agent works better than a hosted app builder.
Order reflects fit for a Chrome extension based on each tool's stated focus; prices checked on official pages 2026-10-15.
AI-first code editor (VS Code-based) with agent, chat, cloud agents.
Anthropic's agentic coding tool for terminal/IDE, included in Claude paid plans.
AI assistant in VS Code/JetBrains/etc + GitHub cloud agent and CLI.
OpenAI coding agent across ChatGPT, cloud, IDE extension and CLI; parallel agents.
Open-source coding agent for VS Code + CLI; bring your own API key.
Fast open-source editor with AI agent; supports external agents (Claude, Codex).
Next: grab the free prompt pack · build your first app guide · take the quiz