Best OpenAI Codex alternatives

Anthropic's agentic coding tool, running in the terminal, IDE, desktop app, and browser, reading your codebase and editing files with explicit approval.

Open-source, git-aware AI pair programmer that runs in your terminal. Same project as "Aider Chat" elsewhere in this directory, now maintained at Aider-AI/aider.

Cognition AI's autonomous software engineer that plans, writes, debugs, and ships code with limited human oversight, across several model backends.

Open-source terminal coding agent with a TUI that works with any model provider, including local models, and supports LSP, MCP and custom agents.

Open-source platform for autonomous coding agents built by All Hands AI, running in a sandboxed Docker environment to fix issues and open pull requests.

Open-source AI agent from Block, runnable as a desktop app or CLI, connecting to external systems via MCP and now governed by the Agentic AI Foundation.

Enterprise AI coding platform built around autonomous "Droids" that plan, code, test, and open pull requests across a codebase, with human review built into the loop.

Google's open-source terminal coding agent built on Gemini models with a 1M-token context window. Shut down for free consumer accounts June 18, 2026.