Retrofit Governance

Add native ACS governance to an existing agent without moving policy logic into the framework adapter.

1. Create the manifest

Start from a manifest under examples/policy-templates/ or generate one with the policy generator. Bind each policy to the intervention points the adapter can mediate.

python -m agent_os.cli.cmd_policy_gen --template strict --output policies/
agt lint-policy policies/manifest.yaml

2. Construct the runtime

from agent_control_specification import AgentControl

runtime = AgentControl.from_path("policies/manifest.yaml")

Runtime folder discovery is not supported. Resolve ACS extends before adapter preflight or use a manifest chain through the native ACS SDK.

3. Attach the framework adapter

from agent_os.integrations.langchain_adapter import LangChainKernel

kernel = LangChainKernel(runtime=runtime)

Use the adapter for the framework lifecycle. Do not pass inline rules, blocked patterns, tool lists, or policy directories to adapter constructors.

4. Handle denials

from agent_os.exceptions import PolicyViolationError

try:
    result = kernel.evaluate_input(context, "user request")
    if not result.allowed:
        raise result.to_policy_violation(PolicyViolationError)
except PolicyViolationError as error:
    print(str(error))
    audit_payload = error.evaluation_result.audit_record()

The public message is sanitized. The structured native evaluation remains attached for trusted audit and dispatch code.

5. Add session and sandbox controls

HostSession owns counters. SandboxConfig owns host resource, network, filesystem, and tool-exposure settings. Keep both outside the manifest policy interpreter.

6. Verify the retrofit

agt test policies/manifest.yaml policies/fixtures.json
pytest tests/

Exercise allow, deny, transform, escalate, and runtime-error paths that the manifest binds. Verify every framework side effect occurs only after its pre-intervention evaluation.

See Framework Integrations and v4 policy-language removal.