Best Claude Agent SDK Alternatives

OpenAI's Python framework for building multi-agent AI applications with GPT models. Provides primitives for creating agents with tool calling, handoffs between specialized agents, guardrails for input/output validation, and tracing for observability. Supports building complex workflows where agents collaborate on tasks. Includes built-in tools for file search, code execution, and web browsing. Designed for production agent systems with structured output and error recovery patterns.

The most widely-used framework for building LLM-powered applications, available in Python and JavaScript. Provides abstractions for chains, agents, RAG, memory, tool usage, and structured output. Integrates with 100+ LLM providers, vector stores, document loaders, and tools. LangSmith offers tracing and evaluation. LangGraph enables stateful, multi-agent workflows with cycles. 100K+ GitHub stars. The de facto standard for LLM application development despite growing alternatives like LlamaIndex.

TypeScript-native framework for building AI agents and workflows with great developer experience. Provides primitives for agents with tool calling, RAG pipelines, workflow orchestration with branching/parallel steps, and integration connectors. First-class TypeScript support with type-safe tool definitions. Local dev server with playground UI for testing. Growing as a LangChain alternative for TypeScript developers building AI apps.