Every option in the catalog for when you need to build your own multi-agent system in code — 25 AI agent frameworks for developers, 25 of them free or freemium, with the pricing tier printed on every row.
Flocci AI Tools lists 25 of them, ordered free tiers first: Agno, AWS Strands Agents, CAMEL, Claude Agent SDK and Cloudflare Agents SDK. Every one of them is free or has a free tier. Each entry states what it uniquely does rather than a score.
23 on this page are marked fully free with no paid plan at all: Agno, AWS Strands Agents, CAMEL, Claude Agent SDK and Cloudflare Agents SDK. The remaining 2 are freemium, trial or paid, and each is labelled with its exact tier so nothing surprises you at sign-up.
Free tools first, then freemium, then trial, then paid, and alphabetically inside each tier. Nobody pays to appear higher: Flocci AI Tools carries no ads, no sponsored slots and no paid listings, so the order reflects price and nothing else.
Cloudflare Agents SDK supports Google sign-in, so you can start without creating a new account. That's 1 of the 25 free AI agent frameworks for developers on this page.
Agno, AWS Strands Agents, CAMEL, Claude Agent SDK and DSPy can be self-hosted or run locally without a browser — useful for privacy, air-gapped networks, or avoiding API rate limits. 22 of the 25 free AI agent frameworks for developers here run offline.
| Tool | Pricing | Type | Listed for |
|---|---|---|---|
| Agno | Free | Agent Frameworks (Developers) | Open-source (Apache-2.0) Python framework, 41.7k GitHub stars |
| AWS Strands Agents | Free | Agent Frameworks (Developers) | Open-source (6,800+ stars) Python and TypeScript SDK from AWS |
| CAMEL | Free | Agent Frameworks (Developers) | Open-source multi-agent framework focused on scaling agent societies and role-playing |
| Claude Agent SDK | Free | Agent Frameworks (Developers) | MIT-licensed Python and TypeScript SDKs exposing the agent loop that powers Claude Code |
| Cloudflare Agents SDK | Free | Agent Frameworks (Developers) | Framework for building and deploying stateful AI agents on Cloudflare Workers |
| DSPy | Free | Agent Frameworks (Developers) | Open-source (MIT) framework from Stanford NLP, 37k+ GitHub stars |
| Firebase Genkit | Free | Agent Frameworks (Developers) | Open-source framework for AI apps in JavaScript, Go, Dart and Python |
| Google Agent Development Kit (ADK) | Free | Agent Frameworks (Developers) | Open-source Python/Java framework from Google for building multi-agent systems |
| Haystack | Free | Agent Frameworks (Developers) | Apache-2.0 framework for context-engineered, production RAG and agent pipelines |
| LangChain | Free | Agent Frameworks (Developers) | MIT-licensed framework of model, tool and retrieval integrations for agents |
| LangChain Deep Agents | Free | Agent Frameworks (Developers) | Batteries-included agent harness with planning, sub-agents and a virtual file system |
| LangGraph | Free | Agent Frameworks (Developers) | Build stateful, multi-agent apps as graphs |
| Mastra | Free | Agent Frameworks (Developers) | Open-source TypeScript framework (Apache 2.0) for agents, workflows and RAG |
| Microsoft Agent Framework | Free | Agent Frameworks (Developers) | Unified open-source framework for building and orchestrating multi-agent systems in Python and .NET |
| Microsoft AutoGen | Free | Agent Frameworks (Developers) | Multi-agent conversation framework |
| OpenAI Agents SDK | Free | Agent Frameworks (Developers) | Lightweight agent orchestration from OpenAI |
| OpenSandbox (Alibaba) | Free | Agent Frameworks (Developers) | Secure, fast runtime for executing untrusted AI-generated code |
| Pydantic AI | Free | Agent Frameworks (Developers) | Type-safe Python agent framework from the Pydantic team, validated structured outputs |
| Qwen-Agent | Free | Agent Frameworks (Developers) | Agent framework built on Qwen 3+ with function calling, MCP and code interpreter |
| Semantic Kernel | Free | Agent Frameworks (Developers) | MIT SDK for integrating LLMs into C#, Python and Java apps |
| smolagents | Free | Agent Frameworks (Developers) | Extremely minimal open-source library (~1,000 lines) from Hugging Face |
| Vercel AI SDK | Free | Agent Frameworks (Developers) | TypeScript toolkit for streaming text, tool calls and agents across many model providers |
| VoltAgent | Free | Agent Frameworks (Developers) | Open-source TypeScript agent framework with memory, tools and sub-agents |
| CrewAI | Freemium | Agent Frameworks (Developers) | Role-based multi-agent 'crews' |
| LlamaIndex | Freemium | Agent Frameworks (Developers) | Leading framework for RAG and data agents |