Migrate Python applications from the Claude Agent SDK to Pydantic AI and, only when needed, Pydantic AI Harness. Use when source code imports `claude_agent_sdk` or relies on Claude Code's agent loop, sessions, built-in tools, hooks, permissions, skills, or subagents. Do not use for the Anthropic Messages SDK or Claude Managed Agents.
Install
npx skills add pydantic/skills --skill migrating-claude-agent-sdk-to-pydantic-ainpx skills add pydantic/skills --skill migrating-claude-agent-sdk-to-pydantic-ai -a claude-code -gnpx skills add pydantic/skills --skill migrating-claude-agent-sdk-to-pydantic-ai -a codex -ggemini skills install https://github.com/pydantic/skills.git --path skills/migrating-claude-agent-sdk-to-pydantic-aigh skill install pydantic/skills migrating-claude-agent-sdk-to-pydantic-aigit clone --depth 1 https://github.com/pydantic/skills /tmp/pydantic__skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/pydantic__skills/skills/migrating-claude-agent-sdk-to-pydantic-ai ~/.claude/skills/migrating-claude-agent-sdk-to-pydantic-ai # Claude Code
cp -R /tmp/pydantic__skills/skills/migrating-claude-agent-sdk-to-pydantic-ai ~/.agents/skills/migrating-claude-agent-sdk-to-pydantic-ai # Codex, Cursor, Gemini CLI, Copilot, OpenCode