DSPy

LangChain

langchain-ai/langchain

Popular

Framework for composing LLM calls, tools and retrieval into applications; the largest LLM app ecosystem.

LangChain.js

langchain-ai/langchainjs

TypeScript port of LangChain for building LLM apps and agents in Node, browsers and edge runtimes.

LlamaIndex

run-llama/llama_index

Popular

Data framework for connecting LLMs to your documents: ingestion, indexing, retrieval and agentic workflows.

Haystack

deepset-ai/haystack

Production-oriented framework by deepset for building RAG pipelines and agents from modular components.

Spring AI

spring-projects/spring-ai

Rising

Spring's portable API for chat models, embeddings, vector stores, tools and MCP in Java applications.

LangChain4j

langchain4j/langchain4j

Java library for integrating LLMs, RAG, tools and agents, with Quarkus and Spring Boot integrations.

Genkit

genkit-ai/genkit

Google's open-source framework for building AI features with flows, tools and evals in TypeScript, Go and Python.

Instructor

567-labs/instructor

Gets validated structured outputs from LLMs using Pydantic models, with retries; ports for TS, Go and more.

BAML

BoundaryML/baml

Rising

Typed prompt-definition language that generates type-safe LLM clients for Python, TypeScript, Go and more.