building-pydantic-ai-agents

Pydantic AI is a Python agent framework for building production-grade Generative AI applications. This skill provides patterns, architecture guidance, and tested code examples for building applications with Pydantic AI. Invoke this skill when: Do not use this skill for: Capabilities are reusable, composable units of agent behavior — bundling tools, hooks, instructions, and model settings. Use Hooks to intercept model requests, tool calls, and runs with decorators — no subclassing needed. Use Agent.from_file to load agents from YAML or JSON — no Python agent construction code needed. Load only the most relevant reference first. Read additional references only if the task spans multiple areas. Load Architecture and Decision Guide only when the user is choosing between abstractions or wants comparison tables and decision trees: Quick reference — model string format: "provider:model-name" (e.g., "openai:gpt-5.2" , "anthropic:claude-sonnet-4-6" , "google-gla:gemini-3-pro-preview" ) Quick reference — key agent methods: run() , run_sync() , run_stream() , run_stream_sync() , run_stream_events() , iter() These are mistakes agents commonly make with Pydantic AI.