Claude Agent SDK vs. OpenAI AgentKit: A Developer's Guide to Building AI Agents

A comprehensive comparison of two leading frameworks for building AI agents, released within days of each other in fall 2025


Last Updated: October 12, 2025 | Both frameworks are newly released and actively evolving. Check official documentation for the latest features.


In October 2025, AI agent development reached an inflection point. OpenAI launched AgentKit on October 6, and just days earlier, on September 29, Anthropic released the Claude Agent SDK alongside Claude Sonnet 4.5. Both represent mature, production-ready approaches to building AI agents, but with fundamentally different philosophies.

Which framework fits your needs? This guide provides a detailed, objective comparison to help you evaluate both options.

mindmap
  root((AI Agent Frameworks))
    OpenAI AgentKit
      Visual Development
        Agent Builder
        ChatKit UI
        Drag-and-Drop
      Managed Infrastructure
        OpenAI Hosting
        Auto-Scaling
        Built-in Safety
      Quick Setup
        Tool Registry
        Pre-built Connectors
        Integrated Testing
    Claude Agent SDK
      Developer Control
        Local Execution
        Custom Tools
        MCP Protocol
      Flexible Deployment
        On-Premises
        Amazon Bedrock
        GCP Vertex AI
      Production Proven
        Claude Code Legacy
        Battle-Tested
        Enterprise Ready
    Key Differences
      Maturity
        AgentKit: New Oct 2025
        Claude: Evolved from Claude Code
      Philosophy
        AgentKit: Managed Speed
        Claude: Developer Autonomy
      Deployment
        AgentKit: OpenAI Only
        Claude: Multi-Cloud

This mindmap shows the core distinctions between the two frameworks. AgentKit prioritizes speed with managed infrastructure, while Claude Agent SDK emphasizes developer control with flexible deployment options.

Understanding the Frameworks

This section explores what each framework offers and how they approach agent development differently.

OpenAI AgentKit

AgentKit is OpenAI's comprehensive platform for building AI agents, featuring:

The platform runs on OpenAI's managed infrastructure, making it product-ready out of the box.

Claude Agent SDK

The Claude Agent SDK (formerly Claude Code SDK) is Anthropic's developer-first framework providing: