In the Stack Overflow Developer Survey 2025, 84% of respondents used or planned to use AI tools, and half of professional developers used them daily; yet more developers distrusted the accuracy of AI output (45.7%) than trusted it (32.7%). Treat an assistant as a fast junior colleague whose every change you review.
AI help now comes in three strengths. Completions predict the next line or edit as you type. Chat and inline edits rewrite a selection or several files on request. Agents take a task ("add form validation and tests"), then loop on their own: read files, edit, run commands, inspect the results, and stop with a diff for you to approve.
| Tool | Form | Individual plans (September 2026) |
|---|---|---|
| GitHub Copilot 29 | Extension for VS Code 550 , JetBrains, Xcode 10 ; CLI; cloud agent | Free; Pro $10; Pro+ $39; Max $100 |
| Cursor 3,457 | VS Code fork with built-in agents | Hobby free; Individual $20 |
| Claude Code 2,500 | Terminal agent; VS Code and JetBrains extensions; desktop app | Included in Claude 2,500 Pro $20; Max from $100 |
| OpenAI Codex 126,827 | Open-source CLI, IDE extension, cloud tasks | Included in ChatGPT Free, Go $8, Plus $20, Pro from $100 |
| Devin 15,459 Desktop (formerly Windsurf 14,485 ) | VS Code-based editor with agent manager | Free; Pro $20 |
| Zed 17,780 | Native editor; edit predictions; runs external agents | Free; Pro $10 |
The market moves fast. Copilot moved chat and agent usage to token-billed GitHub 29 AI Credits in June 2026, while code completions remain unlimited on paid plans. SpaceX completed its purchase of Cursor's maker, Anysphere, in August 2026. Cognition acquired Windsurf in July 2025 and renamed it Devin Desktop in June 2026. Most tools let you choose among models from Anthropic, OpenAI 86 , Google and others, so compare the workflow, not only the model.
Agents work best when a project explains itself. AGENTS.md, an open format now stewarded by the Linux Foundation's Agentic AI Foundation, is read by Codex, Copilot, Cursor, Zed and many others; Claude Code reads CLAUDE.md, which can simply point to the same file.
# Project notes for coding agents
## Commands
- Install: `npm ci`
- Dev server: `npm run dev` (http://localhost:5173)
- Test and lint before finishing: `npm test && npm run lint`
## Conventions
- Semantic HTML first; every image needs meaningful `alt` text.
- CSS lives in `src/styles/`; use custom properties, no inline styles.
- Never commit `.env` files or edit `dist/`.To try an agent, install one and start it inside the project folder:
npm install -g @openai/codex && codex
curl -fsSL https://claude.ai/install.sh | bash && claude