AI SDK Harnesses

The harness section covers the AI SDK harness abstraction: a uniform API for running established agent harnesses such as Claude Code, Codex, and Pi.

• Overview: Understand how harnesses relate to providers, models, agents, streams, and UI primitives.
• HarnessAgent: Create sessions, run turns, manage sandbox lifecycle, and resume harness conversations.
• Tools: Use built-in harness tools, host-executed AI SDK tools, approvals, and sandbox-aware execution.
• Skills: Provide reusable instruction bundles to harness runtimes.
• Harness Adapters: Learn about the available harness adapters.
• Workflow Utilities: Run HarnessAgent turns as durable Workflow DevKit workflows.
• UI: Stream harness output to useChat and build chat routes that preserve harness sessions.
• Terminal UI: Run HarnessAgent in @ai-sdk/tui with a small session adapter.