Agent frameworks tools
Code libraries for agents and RAG. 7 tools we track, checked .
Short answer page: What's the best agent frameworks tool?
Ranked by fit for solo businesses: tools we profile in depth first, then those used in our research notes, then the rest. Affiliate status never changes the order.
- 1
Langfuse
Pick this if you want debugging and evaluating LLM apps.
Open-source LLM observability: tracing, evals and prompt management.
Free plan + paid plans · Free plan: Yes · $0 · then $29/mo · Difficulty 3/5
- 2
pgvector
Pick this if you want vector search in an existing Postgres database.
Open-source vector similarity search extension for Postgres.
Free, open source · Free plan: Yes · Difficulty 4/5
- 3
LangChain
Pick this if you want developers building agents and RAG pipelines.
Open-source framework for building LLM apps and agents, with LangGraph for orchestration.
Free, open source · Free plan: Yes · Difficulty 4/5
- 4
LlamaIndex
Pick this if you want rAG over documents.
Open-source framework for connecting LLMs to your data, plus document parsing services.
Free, open source · Free plan: Yes · Difficulty 4/5
- 5
CrewAI
Pick this if you want multi-agent workflows.
Open-source framework for multi-agent systems, with a hosted platform.
Free, open source · Free plan: Yes · Difficulty 4/5
- 6
Pinecone
Pick this if you want managed vector search at scale.
Managed vector database for semantic search and RAG.
Free plan + paid plans · Free plan: Yes · Difficulty 3/5
- 7
OpenAI Agents SDK
Pick this if you want lightweight agents on OpenAI models.
OpenAI's open-source SDK for tool-using agents with handoffs and tracing.
Free, open source · Free plan: Yes
Side-by-side
| Tool | Pricing model | Free plan | Starting price | Difficulty | Output rights | Best for |
|---|---|---|---|---|---|---|
| Langfuse | Free plan + paid plans | Yes | $0 · then $29/mo | 3/5 | Not a content generator | Debugging and evaluating LLM apps |
| pgvector | Free, open source | Yes | Free | 4/5 | – | Vector search in an existing Postgres database |
| LangChain | Free, open source | Yes | Free | 4/5 | – | Developers building agents and RAG pipelines |
| LlamaIndex | Free, open source | Yes | Free | 4/5 | – | RAG over documents |
| CrewAI | Free, open source | Yes | Free | 4/5 | – | Multi-agent workflows |
| Pinecone | Free plan + paid plans | Yes | See official site | 3/5 | – | Managed vector search at scale |
| OpenAI Agents SDK | Free, open source | Yes | Free | – | – | Lightweight agents on OpenAI models |
"Starting price" is shown only for tools we profile in depth, where we read the official pricing page on . For the others, check the official site.