LlamaIndex began as a RAG framework and is now also an agent framework, with multi-agent orchestration through AgentWorkflow (declaring agents and the hand-offs between them). It is MIT-licensed and supports Python and TypeScript. Its strength remains data: retrieval, indexing, and document workflows. Among the independent frameworks it is the retrieval-first option, where LangGraph is graph-first and CrewAI is role-first. MCP support is available but, as with LangChain, through a separate integration package (llama-index-tools-mcp) rather than the core library. The framework is still on a 0.x version line as of May 2026, though it is widely used in production. LlamaCloud is an optional hosted product; the framework itself runs anywhere. For open-source AI, LlamaIndex is fully open and model-agnostic, reaching providers through its large set of integration packages rather than a single built-in client.
The Stack · Agents · Open source
LlamaIndex
Open framework for data-aware LLM applications; strong on RAG, now also an agent framework via AgentWorkflow. MCP via the llama-index-tools-mcp package.
Sources
- LlamaIndex documentation https://developers.llamaindex.ai/python/framework/
- llama_index LICENSE (MIT) https://raw.githubusercontent.com/run-llama/llama_index/main/LICENSE
- LlamaIndex MCP integration docs https://developers.llamaindex.ai/python/framework/module_guides/mcp/llamaindex_mcp/
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