# Use ACP-compatible harnesses with the AI SDK harness layer

DevFeed: [Use ACP-compatible harnesses with the AI SDK harness layer](<https://devfeed.tech/articles/use-acp-compatible-harnesses-with-the-ai-sdk-harness-layer-1118.md>)

Original publisher: [Read original article](<https://vercel.com/changelog/use-acp-compatible-harnesses-with-the-ai-sdk-harness-layer>)

Author: Felix Arntz

Published: 2026-08-13T00:00:00Z

Content type: release

Language: en

Sources: [Vercel News](<https://devfeed.tech/sources/vercel-news.md>)

Topics: [vercel ai sdk](<https://devfeed.tech/topics/vercel-ai-sdk.md>), [Protocol (disambiguation)](<https://devfeed.tech/topics/protocol.md>), [SDKs](<https://devfeed.tech/topics/sdks.md>), [coding](<https://devfeed.tech/topics/coding.md>), [Claude Code](<https://devfeed.tech/topics/claude-code.md>), [codex](<https://devfeed.tech/topics/codex.md>)

Tags: [agent](<https://devfeed.tech/tags/agent.md>), [ai](<https://devfeed.tech/tags/ai.md>), [claude-code](<https://devfeed.tech/tags/claude-code.md>), [codex](<https://devfeed.tech/tags/codex.md>), [integration](<https://devfeed.tech/tags/integration.md>), [opencode](<https://devfeed.tech/tags/opencode.md>), [sdk](<https://devfeed.tech/tags/sdk.md>)

## AI overview

The AI SDK harness layer now supports Agent Client Protocol-compatible harnesses through the new @ai-sdk/harness-acp package. It acts as a meta adapter for harnesses that provide ACP-compatible packages, while direct adapters remain preferable for Claude Code and Codex when tighter integration is needed.

## Source excerpt

The AI SDK harness layer now supports any Agent Client Protocol (ACP)-compatible harness with HarnessAgent through the new @ai-sdk/harness-acp package. Previously, every harness adapter wrapped one specific runtime (Claude Code, Codex, Pi, Deep Agents, OpenCode). @ai-sdk/harness-acp wraps the protocol instead. It is a meta adapter: rather than adapting a single harness, it lets you build an adapter for any harness that ships an ACP-compatible package. Implement a harness by passing that package to createACP and configure basic harness mapping. Then pass it to HarnessAgent like any other harness: ACP is an abstraction over coding harnesses, but the AI SDK harness layer stays deliberately decoupled from it. Not every harness supports ACP, and for some, ACP limits or changes how well they expose their internal behaviors, so a direct adapter can produce a tighter integration. For Claude Code and Codex, prefer the direct @ai-sdk/harness-claude-code and @ai-sdk/harness-codex adapters over an ACP-based implementation; reach for @ai-sdk/harness-acp when a harness has no direct adapter but ships an ACP-compatible package. Read the ACP harness documentation to get started. Read more