# Tools Landscape

The agent-coding tool market stabilized around four shapes: terminal agents, IDE-integrated agents, VS Code extension agents, and lightweight pair-programmers. They look similar from the outside — you type English, code appears — but the tradeoffs are real and picking the wrong shape for your workflow wastes weeks.

This page compares the serious options as of April 2026. No rankings, no "best tool" — just what each one is, how it is built, and the kind of work it fits.

## The four tools worth knowing

| Tool | Shape | Primary loop | License |

| --- | --- | --- | --- |

| Claude Code | Terminal CLI + IDE extensions | Autonomous read-plan-edit-verify loop with permission model | Proprietary (Anthropic) |

| Codex CLI | Terminal, written in Rust | Autonomous agent with OS-level sandboxing | Open source (OpenAI) |

| Cursor Agent | Forked VS Code (full IDE) | Agent mode inside the editor with checkpoints | Proprietary |

| Cline | VS Code / JetBrains extension | Plan/Act modes with explicit approval on every change | Open source (Apache 2.0) |

A fifth tool, Aider, is worth mentioning for a specific niche: terminal-based, git-native, and deliberately small.

Sources: [Claude Code docs](https://code.claude.com/docs/en/overview), [OpenAI Codex CLI](https://developers.openai.com/codex/cli/), [Cursor Agent docs](https://cursor.com/docs/agent), [Cline docs](https://docs.cline.bot/getting-started/what-is-cline), [Aider](https://aider.chat/).