Pydantic AI vs OpenAI Agents SDK
The OpenAI Agents SDK is a small Python library built close to OpenAI’s own API: agents, handoff primitives, guardrails, and access to the hosted tools. Pydantic AI runs one typed Agent on any provider, with structured output validated by Pydantic and a Harness SDK of capabilities from sandboxes to sub-agents.
Pydantic AI is one part of a stack: the Harness SDK for capabilities and complete agents, Pydantic Evals for evaluation, Pydantic Graph for graph-based workflows, Pydantic Logfire for observability, and Pydantic itself for validation. The tables below cover the whole of it.
Already built on the OpenAI Agents SDK? The migrating-openai-agents-sdk-to-pydantic-ai skill ports an existing application to Pydantic AI one working path at a time, preserving behavior rather than translating API names.
| OpenAI Agents SDK | Pydantic AI and Harness SDK | |
|---|---|---|
| Language | Python | Python |
| License | MIT | MIT |
| Model providers | OpenAI first; others via LiteLLM | Many |
| Extensibility | Tools, guardrails, handoffs | Capabilities and toolsets; 50+ with the Harness SDK |
| Harnesses | SandboxAgent, or build your own | Built-in Coder and Researcher, or compose your own |
| Observability | OpenAI tracing, OTel via adapters | OpenTelemetry, including Pydantic Logfire |
| Durable execution | Yes | Seven integrations |
| Interfaces | REPL demo loop | CLI, web chat, AG-UI, Vercel AI, ACP (experimental), GitHub Agentic Workflows |
| Realtime voice | Yes | Realtime |
| Evals | Yes | Pydantic Evals |
| Image generation | Provider-hosted tools only | Image Generation |
| OpenAI Agents SDK | Pydantic AI and Harness SDK | |
|---|---|---|
| Multi-agent | Yes | Subagents, delegation, or pydantic-graph |
| Planning | No | Planning |
| Skills | Yes | Skills |
| Memory | Yes | Memory |
| Compaction | Yes | Compaction |
| Guardrails | Yes | Guardrails |
| Code sandboxes | Yes | Execution environments |
| Browser use | Bring your own Computer | Web & research |
Can I build a coding agent on Pydantic AI? Yes. Give your agent the
Coder() capability, or assemble your own from the
same Agent; the harness repository has a
complete coding agent
built from the pieces Coder puts together.
Can I run my agents in CI? Yes. GitHub Agentic Workflows runs Pydantic AI agents
from a Markdown workflow file in GitHub Actions, or run a Python script directly with uv run;
nothing requires an Action.