Agent Frameworks active ★ 4.5 open-source · $39/month Free tier available Verified Feb 2026

The most widely used framework for building LLM-powered applications and AI agents. Provides abstractions for chaining LLM calls, connecting to tools and data sources, and building complex agentic workflows. LangGraph extends it for stateful multi-agent systems.

Use Cases

Building LLM-powered applications and chatbots
RAG pipelines for document Q&A
Multi-step AI agent workflows
LLM call orchestration and chaining
Evaluating and monitoring LLM applications (via LangSmith)

Pros

Largest ecosystem and community for LLM app development
LangGraph adds stateful, multi-step agent capabilities
LangSmith provides essential observability and evaluation
Supports every major LLM provider
Extensive documentation and tutorials

Cons

Abstractions can be over-engineered for simple use cases
API changes frequently -- breaking changes between versions
Learning curve is steep for the full framework
Can add unnecessary complexity vs direct API calls
Performance overhead from abstraction layers

Pricing

Plan	Price
Open Source	Free
LangSmith Cloud	$39/monthly

Works With

CrewAILangChain for single-agent pipelines, CrewAI for multi-agent collaboration ChatGPTLangChain orchestrates GPT-4 API calls in complex agent workflows OpenAI APIOften used with LangChain to build complex AI applications and agentic workflows, abstracting API ca Anthropic APIIntegrates with LangChain for building complex LLM applications and agent workflows.Google AI StudioCan be used in conjunction with LangChain for more complex application orchestration and integration Mistral AIMistral models can be easily integrated into LangChain applications for building complex LLM workflo GroqCan be integrated with LangChain to build complex LLM applications and agent frameworks, leveraging Together AIIntegrates seamlessly with LangChain for building complex LLM applications and agents.ReplicateLangChain can be used to build AI agents and applications that leverage Replicate for running specif Hugging FaceLangChain agents often leverage models hosted on Hugging Face for various tasks, including LLMs and CohereCohere models are easily integrated into LangChain for building complex LLM applications and agent f OpenRouterCan be used as an LLM provider within LangChain applications, offering access to its diverse model c

Comparisons

LangChain vs AutogenSide-by-side comparison LangChain vs AutoGPTSide-by-side comparison LangChain vs CrewAISide-by-side comparison LangChain vs Databricks AISide-by-side comparison LangChain vs DevinSide-by-side comparison LangChain vs Google AI StudioSide-by-side comparison LangChain vs VapiSide-by-side comparison

LangChain