Best agent frameworks for building AI agents

Code-first Go toolkit for building agents with a tool ecosystem, composable multi-agent systems and Cloud Run deployment.

• 8.9K GitHub stars
• Active in the last 30 days
• Open source (Apache-2.0)

★ 8.9KLast active Oct 23, 2026

Python framework of interoperable components and integrations for building agents and LLM apps, with LangGraph and Deep Agents layered above it.

• Most GitHub stars here (148,371)
• Most weekly downloads here (37.3M)
• Active in the last 30 days

★ 148.4K↓ 37.3M/wkLast active Oct 24, 2026

Typed Python SDK for building agents with swappable model providers, plus optional capabilities for memory, sub-agents, planning and durable execution.

• 20.8K GitHub stars
• Active in the last 30 days
• Open source (MIT)

★ 20.8K↓ 1.5M/wkLast active Oct 24, 2026

Open-source toolkit for building, evaluating and deploying agents in Python, TypeScript, Go, Java and Kotlin, tuned for Gemini but model-agnostic.

• 22K GitHub stars
• Active in the last 30 days
• Open source (Apache-2.0)

★ 22K↓ 2.4M/wkLast active Oct 24, 2026

Python SDK that runs the Claude Code agent loop inside your own program, with custom tools and hooks written as Python functions.

• 8.3K GitHub stars
• Active in the last 30 days
• Open source (MIT)

★ 8.3K↓ 7.9M/wkLast active Oct 24, 2026

Python framework and runtime for building agents, serving them over a REST API and MCP server, and managing them from a web control plane.

• 42.9K GitHub stars
• Active in the last 30 days
• Open source (Apache-2.0)

★ 42.9K↓ 519.4K/wkLast active Oct 24, 2026

Open-source agent harness from LangChain for building agents with code, with LangSmith for testing and monitoring.

• 3.4K GitHub stars
• Active in the last 30 days
• Open source (MIT)

★ 3.4K↓ 2.3M/wkLast active Oct 22, 2026

TypeScript SDK that gives programs Claude Code's built-in tools for reading, editing and running code, installed from npm.

• 1.8K GitHub stars
• Active in the last 30 days
• For TypeScript

★ 1.8K↓ 8.1M/wkLast active Oct 23, 2026

Python agent framework from Alibaba that lets the model drive tool use, with team pipelines, MCP, agent skills, A2A, memory and tracing.

• 33.8K GitHub stars
• Active in the last 30 days
• Open source (Apache-2.0)

★ 33.8K↓ 50.9K/wkLast active Oct 23, 2026

Rails framework for building AI agents as controllers, with provider gems for OpenAI, Anthropic, Ollama and more.

• Active in the last 30 days
• Open source (MIT)
• For Ruby

★ 985Last active Oct 22, 2026

Python SDK for building agents on Google Antigravity and Gemini, with the agent loop handled by the runtime.

• 3.8K GitHub stars
• Active in the last 30 days
• Open source (Apache-2.0)

★ 3.8K↓ 126.5K/wkLast active Oct 13, 2026

Sample projects for the Strands Agents SDK, showing how to build agents in Python and TypeScript; not intended for production use.

• Active in the last 30 days
• Open source (Apache-2.0)
• For Python and TypeScript

★ 913↓ 8.9M/wkLast active Oct 21, 2026

CLI-first Python agent framework and coding agent with MCP, A2A and Agent Skills support, live streaming and human input.

• 3.9K GitHub stars
• Active in the last 30 days
• Open source (Apache-2.0)

★ 3.9K↓ 19.5K/wkLast active Oct 22, 2026

TypeScript agent framework on a Rust runtime, where runs are checkpointed, replayed with zero LLM calls and resumed after a crash.

• 1.4K GitHub stars
• Active in the last 30 days
• Open source (Apache-2.0)

★ 1.4K↓ 62/wkLast active Oct 22, 2026

Python framework for structured LLM outputs and agentic workflows built from tasks, agents and threads.

• 6.2K GitHub stars
• Open source (Apache-2.0)
• For Python

★ 6.2K↓ 61.8K/wkLast active Sep 23, 2026