Best Codex Alternatives

Amp Frontier Corporation's multi-model coding agent for terminal, web, and IDE-connected workflows. It uses GPT-5.6, Claude Fable 5, and fast models across low, medium, high, and ultra modes, with subagents, an Oracle second-opinion model, shared threads, remote orbs, MCP, and plugins. Pricing combines a daily free credit grant, $20/$200 monthly subscriptions, and optional pay-as-you-go credits.

Open-source terminal-based AI coding agent built in Go by the SST team, with a rich TUI (Bubble Tea) supporting 75+ model providers including OpenAI, Anthropic, Gemini, Bedrock, Groq, and OpenRouter. Features vim-like editing, persistent SQLite sessions, and LSP integration for 40+ languages. Fully free with no vendor lock-in, it has rapidly grown to 95k+ GitHub stars.

Anthropic's agentic CLI coding tool that delegates complex tasks to Claude directly from the terminal. Understands entire codebases via automatic context gathering, edits multiple files, runs shell commands, and manages Git workflows autonomously. Supports CLAUDE.md for persistent project instructions, integrates with VS Code and JetBrains, and uses Claude Opus/Sonnet with extended thinking for complex architectural decisions. Built for terminal-first developers.

Terminal-based AI pair programmer with deep git integration. Auto-commits changes with meaningful messages and creates repository maps for navigating large codebases. Works with Claude, GPT, DeepSeek, and local models. One of the most popular open-source AI coding tools, known for its reliability, broad model support, and seamless command-line workflow.

System of specialized AI Droids — Code, Knowledge, Reliability, and Product — each optimized for specific development tasks. Ranked #1 on Terminal-Bench with 58.75% score. BYOK model with support for Anthropic and OpenAI models. Enterprise-focused approach that treats AI coding as a team of specialized agents rather than a single general-purpose assistant.

Grok Build is xAI's terminal-first coding agent for planning, editing, testing, and reviewing code from a local CLI. The early beta exposes subagent controls, worktree mode, headless JSON output, best-of-N parallel attempts, sandbox profiles, and experimental memory. It fits developers comparing Claude Code, Codex, and Gemini CLI for local agentic workflows with deeper parallel execution.

LSP-enhanced terminal coding agent from Charmbracelet with the broadest cross-platform support including Android. Features mid-session model switching and MCP extensibility for custom tool integration. Combines the elegance of Charmbracelet's TUI toolkit with practical coding assistance, offering a polished terminal experience for developers on any platform.

Pi Coding Agent is an MIT-licensed Node.js CLI from earendil-works for building and running coding agents in a local terminal. The current package describes a read/bash/edit/write toolset and session management, while the repo positions Pi as a unified LLM API, agent loop, TUI, and coding-agent CLI. It is best framed as a lean, self-extensible BYO-model toolkit rather than a managed IDE.

Terminal-based AI coding agent from Moonshot AI, powered by Kimi K2.5 with a 256K context window that achieves 76.8% on SWE-Bench Verified. Reads and edits code, executes shell commands, fetches web pages, and autonomously plans multi-step development workflows through natural language. Moonshot's entry into the AI coding agent market, leveraging their strength in large-context language models.

ZCode is Z.ai’s Agentic Development Environment for GLM-5.2 coding workflows. The desktop app combines a first-party coding agent, goal mode, model/provider setup, MCP server management, Git and terminal context, remote phone control, usage stats and safety confirmation modes so developers can plan, implement, review and iterate on long-running software tasks from one workspace.