Use ACP-compatible harnesses with the AI SDK harness layer
By Steven Van ·
The AI SDK harness layer now supports any Agent Client Protocol (ACP)-compatible harness with HarnessAgent through the new @ai-sdk/harness-acp package.
Vercel's AI SDK harness layer now supports any Agent Client Protocol (ACP) compatible harness through a new @ai-sdk/harness-acp package. Until now, each harness adapter wrapped one specific runtime, such as Claude Code, Codex, Pi, Deep Agents or OpenCode. The new package wraps the protocol instead, so developers can build an adapter for any harness that ships an ACP-compatible package by passing it to createACP and configuring the harness mapping, then use it with HarnessAgent like any other harness.
Vercel still recommends the direct @ai-sdk/harness-claude-code and @ai-sdk/harness-codex adapters for those two runtimes, since ACP can limit how well some harnesses expose their internal behaviour. The ACP route is for harnesses that have no direct adapter but do ship an ACP-compatible package. Read the full announcement for setup details.
