Microsoft is rolling out a new open-source framework called Agent Control Specification (ACS), designed to give developers more precise oversight over how autonomous AI agents behave once deployed. Announced on June 2, 2026, the specification creates a standardized governance layer that lets engineering, compliance, and security teams write policy files defining exactly what an agent is permitted to do, what it must avoid, when human sign-off is required, and what activity should be logged for later auditing. These policies are evaluated at multiple "interception points" throughout an agent's workflow, rather than only at the start of a task, helping organizations catch problematic actions before they cascade into larger failures.
The launch comes as companies increasingly struggle with fragmented approaches to AI oversight. Today, developers typically rely on a mix of system prompts, custom application code, and external classifiers to constrain agent behavior, but these methods often result in inconsistent enforcement that is difficult to audit or reuse across different systems and frameworks. ACS consolidates these scattered controls into a single specification that can be applied uniformly, regardless of the underlying agent framework in use. The tool can be used to allow an action, block it outright, redact sensitive information from a response, or escalate the decision to a human reviewer when a policy threshold is met.
Beyond simple allow-or-block logic, ACS supports more sophisticated evaluation mechanisms. Developers can plug in classifiers to categorize inputs and outputs, deploy large language models in a "judge" role to evaluate whether agent behavior aligns with defined policies, and embed custom logic to verify tool selection and call accuracy. Policy checks run before an agent receives input, before it invokes an external tool, after that tool returns results, and before the final response is delivered to the user, giving teams continuous visibility into the decision chain.
Microsoft's broader bet is that standardized governance will be essential as AI agents take on more responsibilities inside enterprise software. By releasing ACS as an open-source project, the company is signaling that it wants industry-wide buy-in rather than a proprietary standard, positioning the specification as a common foundation that any organization or framework provider can build on. The move reflects growing awareness across the industry that as agentic AI moves from prototypes into production, the lack of consistent guardrails has become one of the biggest obstacles to safe, scalable deployment.