Which Agent Frameworks tools are open source?

15 of the 18 we track have a public repository: AutoGen (CC-BY-4.0), CrewAI (MIT), Goose (Block) (Apache-2.0), Agno (Apache-2.0), LangGraph (MIT), Semantic Kernel (MIT), and 9 more. Licence matters more than the label — check whether the licence covers the production server as well as the library.

What does an Agent Frameworks tool actually cost?

Published monthly prices run from $20 to $150, averaging about $70/month across 4 tools that publish a figure. 18 offer a free tier. The rest quote contact-sales or usage-based pricing, where the sticker price matters less than your usage volume.

Which Agent Frameworks tools are actively maintained?

Most recent commits among the open-source options: CrewAI (2026-08-13), Goose (Block) (2026-08-13), Agno (2026-08-13). A quiet repository isn't automatically a problem — a stable library needs fewer commits than a young one — but a year of silence is worth asking about.

Agent Development Frameworks

All 18 Agent Frameworks tools on AgentsIndex. Filter, sort, and compare.

18 listed18 free15 open sourceavg $70/month

Reviewed by AgentsIndex · Updated Aug 14, 2026

The Agent Frameworks catalog on AgentsIndex lists 18 tools built for this job. Most are built for developers, engineers, small teams. 18 have a free option, 15 are open source. It's one of the more active categories with 14 tools shipping releases in the last 90 days.

CAMEL-AI

Open-source framework for code-first, stateful agent workflows.

Agent Frameworks

CAMEL-AI is an open-source agent framework for code-first orchestration, with Workforce, Connect to RL, and MCP support.

Dust

AI agents connected to company data and tools.

Agent Frameworks

Dust connects AI agents to company data and tools, with Team orchestration, API access, and Pro at $29/month per user.

AutoGen

Framework for prototyping and shipping multi-agent apps.

Agent Frameworks

AutoGen builds multi-agent apps with Studio, AgentChat, Core, and Extensions; supports Python,.NET, Docker, and gRPC worker runtimes.

Agent.ai

A marketplace for discovering and combining AI agents into workflows.

Agent Frameworks

Agent.ai lets teams combine AI agents for research, outreach, and follow-up. Pro costs $25/mo.

Vertex AI Agent Builder

Google Cloud platform for building and governing enterprise AI agents.

Agent Frameworks

Vertex AI Agent Builder builds and governs enterprise AI agents, with BigQuery, Pub/Sub, and API integration. Plans: Free, Pay as you go, Custom.

Goose (Block)

A local AI agent for code, research, writing, and automation.

Agent Frameworks

Goose (Block) runs local AI workflows with 70+ MCP extensions, Recipes, and subagents across desktop, CLI, and API.

Letta

Stateful memory platform for building persistent LLM agents

Agent Frameworks

Letta is an agent framework for developers to add memory and state to LLMs, helping build persistent, self-improving agents.

LangGraph Platform

Deploy and govern production agents with tracing, evals, and APIs.

Agent Frameworks

LangGraph Platform deploys production agents with tracing, evals, Fleet, and one-click APIs. Plans start at $0/seat/month.

Botpress

AI agent building and support automation with Studio, Desk, and Knowledge Bases.

Agent Frameworks

Botpress builds AI agents with Studio, Desk, and Knowledge Bases. Plans start at Free $0, then Plus $150/mo.

Swarms

Multi-agent AI operations through one API and workflow layer.

Agent Frameworks

Swarms routes multi-agent workflows through one API, with telemetry, marketplace access, and Pro at $19.99/month.

Agency Swarm

Open-source framework for coordinating agent roles, prompts, and tools.

Agent Frameworks

Agency Swarm coordinates multi-agent workflows with custom roles, prompt control, and FastAPI integration. It has 4,392 GitHub stars.

Agno

Python agent framework and runtime with FastAPI scaffolding.

Agent Frameworks

Agno builds and runs AI agents with FastAPI scaffolding, tracing, and evaluations. Plans run Free, Pro $150/mo, and Enterprise custom.

PydanticAI

Typed agent workflows with explicit tools, hooks, and validation.

Agent Frameworks

PydanticAI builds typed agent workflows with Pydantic models, Function Tools, and Hooks, with integrations across OpenAI, Anthropic, and LangChain.

Haystack

Open-source AI pipelines with explicit control over retrieval, tools, and memory.

Agent Frameworks

Haystack is an open-source AI orchestration framework for modular pipelines, advanced RAG, and agents. Used by NVIDIA and AWS.

Google ADK

Agent framework for building and running production agents.

Agent Frameworks

Google ADK builds and runs production agents with graph-based workflows, Components, and a Visual Builder. Google Cloud is a named user.

Semantic Kernel

A framework that turns prompts and APIs into function calls.

Agent Frameworks

Semantic Kernel turns prompts and APIs into function calls for AI agents, with C#, Python, and Java support.

CrewAI

Orchestrate collaborative AI agent workflows with visual control and APIs.

Agent Frameworks

CrewAI orchestrates AI agents with visual workflows, tracing, and a REST API. Pro Plan is $99/month; Enterprise is custom.

LangGraph

Framework for reliable AI agents with low-level control.

Agent Frameworks

LangGraph builds reliable AI agents with Observability and Evaluation, starting Free and scaling to Pro at $99/month.

Agent Development Frameworks

About Agent Frameworks on AgentsIndex

Which Agent Frameworks tools are open source?

What does an Agent Frameworks tool actually cost?

Which Agent Frameworks tools are actively maintained?