MassGen
🚀 MassGen is an open-source multi-agent scaling system that runs in your terminal, autonomously orchestrating frontier models and agents to collaborate, reason, and produce high-quality results. | Join us on Discord: discord.massgen.ai
MassGen is an open-source multi-agent scaling system that orchestrates multiple frontier AI models to collaborate, reason, and produce high-quality results through parallel refinement and collective validation. The system runs in your terminal, coordinating agents from OpenAI, Anthropic, Google, xAI, and other providers to tackle complex tasks where each agent observes, critiques, and builds on others' work across cycles of refinement. Agents vote on the best collectively validated answer, with a real-time TUI showing coordination timelines, agent status, and consensus building. It supports MCP integration, file operations, custom tools, and can be used via CLI, Python API, or as an OpenAI-compatible HTTP server.
Key Features
Use Cases
- 01Complex research tasks requiring multiple AI perspectives and consensus validation
- 02Code development with multi-agent review, testing, and implementation workflows
- 03Long-form content generation with iterative refinement and quality evaluation
- 04Data analysis combining web search, computation, and synthesis from multiple models
- 05Project integration where agents collaborate on existing codebases with granular permission control
- 06Automated workflows requiring parallel agent execution with structured task planning
Related Agents
View morehermes-agent
The agent that grows with you
agency-agents
A complete AI agency at your fingertips - From frontend wizards to Reddit community ninjas, from whimsy injectors to reality checkers. Each agent is a specialized expert with personality, processes, and proven deliverables.
openinterpreter
A coding agent for open models like Kimi K3
cline
Autonomous coding agent as an SDK, IDE extension, or CLI assistant.
MassGen — FAQ
What is MassGen?+
MassGen is a multi-agent orchestration framework that coordinates multiple frontier AI models (GPT-5, Claude, Gemini, Grok, etc.) to collaborate on complex tasks through parallel processing, iterative refinement, and collective voting. Each agent tackles the full problem while observing and building on others' work until they reach consensus.
How do I install MassGen?+
Install via pip with 'pip install massgen' (requires Python 3.11+) or use uv for faster installation: 'pip install uv && uv venv && uv pip install massgen'. Run 'massgen --setup' to configure API keys, Docker, and skills, then 'massgen --quickstart' to create your first multi-agent configuration.
What API keys do I need?+
You need at least one provider API key (OPENAI_API_KEY, ANTHROPIC_API_KEY, GOOGLE_API_KEY, or XAI_API_KEY) stored in a .env file in your working directory. Additional providers like Azure OpenAI, Cerebras, Together AI, Groq, and OpenRouter are optional. The --setup command guides you through key configuration.
Which AI clients does MassGen work with?+
MassGen can be integrated into Claude Code, OpenAI Codex, GitHub Copilot, Cursor, and 40+ other AI agents via the Agent Skills standard using 'npx skills add massgen/skills'. It also runs as a standalone CLI tool, Python API (with LiteLLM integration), or OpenAI-compatible HTTP server.
Is MassGen free to use?+
MassGen itself is open-source under Apache 2.0 license and free to use. However, you'll incur costs from the underlying AI provider APIs (OpenAI, Anthropic, Google, etc.) based on their respective pricing. Local model support via LM Studio, vLLM, or SGLang can reduce or eliminate API costs.
Can MassGen access my local files?+
Yes, through context_paths configuration or --cwd-context CLI flag, MassGen can grant agents read or write access to specific directories. The permission system includes protected paths, OS-level sandboxing via Anthropic's sandbox-runtime, and application-layer approval workflows to control file operations. All file access is logged and can be restricted by agent role.
How do I install MassGen?+
Open the source repository on GitHub and follow its README. MassGen is a agent — MCP Agents Market links you directly to the official repo.
Is MassGen free?+
MassGen is an open-source project hosted on GitHub. Check the repository for its license and any usage requirements.