free agent-framework Engineers
LangChain
The most popular framework for building AI applications and agents with support for multiple LLM providers.
3.5/5
Pros
- + Open source, free to use
- + Huge ecosystem of integrations (700+)
- + Supports all major LLM providers
- + LangGraph for complex agent flows
- + LangSmith for monitoring and debugging
Cons
- − Over-abstraction for simple tasks
- − Frequent breaking changes between versions
- − Steep learning curve — many concepts to learn
- − Documentation sometimes lags behind code
What Is LangChain
LangChain is a Python/JavaScript framework for building AI applications. It provides abstractions for working with LLMs, tools, memory, and agents.
When to Use It
Good for:
- Complex multi-step agents
- RAG systems with multiple sources
- Projects using different LLM providers
- Prototyping AI applications
Not ideal for:
- Simple API calls to Claude/GPT (use the SDK directly)
- Projects that need maximum performance
- Teams that don’t want to learn another framework
LangGraph
LangGraph is a separate library from LangChain for building agent systems as graphs:
- Define nodes (steps)
- Connect them with edges (transitions)
- Add conditional logic
- Get a state machine with loop support
Alternatives
If LangChain feels like overkill:
- Claude SDK + Tool Use — for simple agents
- CrewAI — for multi-agent systems
- Haystack — for RAG-focused projects