Forge is an open-source AI pair programmer that lives in your terminal. It works with Claude, GPT, the OpenAI o-series, Grok, DeepSeek, Gemini and 300+ other models, and wraps them in a development environment with agents that can read your codebase, write patches, run commands and manage git. The project has earned about 7,600 stars on GitHub and is in very active development in 2026.
Forge offers three ways to work. Interactive mode is a full terminal UI for multi-step sessions; one-shot mode answers a single prompt from the command line (including handy subcommands like AI-generated commits and natural-language-to-shell translation); and a ZSH plugin adds a : prefix so you can talk to agents without ever leaving your shell prompt. It ships with specialized built-in agents — one that implements, one that researches read-only, one that plans — and lets you define your own, attach files with fuzzy search, and resume conversations like switching directories. Under the hood it supports MCP servers, semantic search over your workspace, a restricted sandbox mode for safety, and provider credentials managed through a simple login flow. For developers who like Claude Code-style workflows but want model freedom and open source, Forge is one of the most complete alternatives.
: commandsForge is free and open source under the Apache 2.0 license. You bring your own model provider accounts or API keys and pay those providers directly.
Forge is for developers who want a powerful, model-agnostic coding agent in the terminal — with the freedom to switch between Claude, GPT, Grok, DeepSeek and local models at will.