Mastra’s May 14 release adds @mastra/acp@0.1.0, a new package for running ACP-compatible coding agents as Mastra tools or lightweight subagents. The release frames ACP agents as usable anywhere Mastra accepts a SubAgent, including supervisor delegation, workflow steps, and the Inngest workflow adapter.
The category signal is simple: coding agents are becoming composable runtime components. Instead of treating an ACP-compatible coding agent as a standalone CLI outside the application graph, Mastra can wrap it as createACPTool(...) or instantiate it as an AcpAgent. A supervisor can then delegate coding work to that subagent, and workflows can treat it as an agent-backed step.
That matters for Open Orchestrators readers because it narrows the gap between “agent framework” and “coding-agent control plane.” ACP gives the coding agent side a protocol surface. Mastra is now giving that surface a place inside its TypeScript agent/workflow runtime.
The same release also adds agent metadata for filtering, cloning, and dynamic resolution; enterprise foundations for admin model policies and role-aware capabilities; better workspace.read_file handling for native media parts and safer binary behavior; lightweight observability trace listing; and improved retry visibility in workflow traces. Those are useful platform moves, but the ACP package is the orchestration headline.
The interesting next question is whether ACP-compatible coding agents become normal building blocks inside agent systems: one node in a supervisor graph, one step in a workflow, one tool behind a product agent, or one specialized worker among many. Mastra’s release is a concrete step in that direction.
Source confidence: High for the release name, package, date, and highlighted capabilities. The source is the official Mastra GitHub release for @mastra/core@1.34.0 and @mastra/acp@0.1.0. Medium for ecosystem implications because the release documents capability, not independent adoption or production reliability.
Evidence:
Explicit non-claims:
- This update does not claim ACP is universally adopted across coding agents.
- This update does not benchmark
@mastra/acpagainst direct CLI orchestration or other agent runtimes. - This update does not claim every ACP-compatible agent works in every Mastra deployment without adapter-specific configuration.