Claude Agent SDK

Reading on agents

• Agents need a durable hostThe loop is a weekend project. The part where it keeps working at three in the morning is the actual product, and almost nobody budgets for it.

• OpenAI Agents SDKLightweight primitives for handoffs, guardrails and tracing.
• LettaAgent runtime with persistent, editable memory as a first-class primitive.

Listed as an alternative to

• OpenAI Agents SDKOpenAI Agents SDKLightweight primitives for handoffs, guardrails and tracing.Use when A small, legible set of primitives for handoffs and guardrails.Skip when You need multi-provider abstraction at every layer.Apache-2.0 · self-hosted · free

Also in agents

• LangChainLangChainComposable abstractions for model calls, tools and state.Use when Tool use and state, in an ecosystem where the answers already exist.Skip when You want a thin, legible core — this is a large surface.MIT · self-hosted · free
• LlamaIndexLlamaIndexData-centric framework for retrieval and agent workflows.Use when Data-centric work where retrieval is the centre of the problem.Skip when You need agent orchestration more than data access.MIT · self-hosted · free
• Pydantic AIPydantic AIType-safe agent framework that leans on Pydantic models.Use when Type-safe agents where schema correctness is the priority.Skip when You want a batteries-included ecosystem.MIT · self-hosted · free
• AutoGenAutoGenMicrosoft research project for conversable multi-agent systems.Use when Research into conversable multi-agent systems.Skip when You need something stable and documented for production.MIT · self-hosted · free
• CrewAICrewAIRole-based orchestration where agents collaborate as a crew.Use when Role-based orchestration where agents are framed as a team.Skip when You want direct control over the loop itself.MIT · self-hosted · free
• Semantic KernelSemantic KernelMicrosoft SDK for embedding AI steps into .NET and Python apps.Use when Embedding AI steps into an existing .NET estate.Skip when Your stack is not .NET.MIT · self-hosted · free
• MastraMastraTypeScript agent framework with typed workflows and evals.Use when TypeScript agents with typed workflows and evals built in.Skip when You are working in Python.Apache-2.0 · self-hosted · free
• OpenAI Agents SDKOpenAI Agents SDKLightweight primitives for handoffs, guardrails and tracing.Use when A small, legible set of primitives for handoffs and guardrails.Skip when You need multi-provider abstraction at every layer.Apache-2.0 · self-hosted · free
• AgnoAgnoMinimal agent runtime centered on model-agnostic tool interfaces.Use when A minimal agent runtime with model-agnostic tool interfaces.Skip when You need the wider ecosystem around it.MPL-2.0 · self-hosted · free
• LettaLettaAgent runtime with persistent, editable memory as a first-class primitive.Use when Agents whose memory is a first-class, inspectable and editable state.Skip when You want memory to be a detail the framework handles for you.Apache-2.0 · self-hosted · free
• smolagentssmolagentsMinimal code-first agent loop from the Hugging Face team.Use when Reading the whole agent loop in a page — it is deliberately tiny.Skip when You need a rich tool ecosystem around it.Apache-2.0 · self-hosted · free
• Vercel AI SDKVercel AI SDKProvider-agnostic building blocks for streaming apps and agents.Use when Streaming model calls in a TypeScript app, provider-agnostically.Skip when You need agent orchestration rather than model calls.Apache-2.0 · self-hosted · free