An architectural decision control plane is the coordination layer that identifies which reviewed engineering decisions apply to a code change, supplies those decisions to an AI coding agent, records citations and routes machine-checkable consequences to CI. It does not replace Git, ADRs or policy engines; it connects their authority, retrieval and evidence.
Why a control plane is different from an ADR tool
An ADR tool records why a choice was made. A control plane makes that choice operational at the moment an agent plans or changes code. The distinction matters because a perfectly written decision can still be absent from the agent's task context, uncited in the pull request and disconnected from the check that should protect it.
The useful unit is therefore a chain: reviewed record, applicability, retrieval, citation, verification and evidence. Each link has a narrower claim than the whole system. A retrieval result is not enforcement, and a passing policy check is not proof that every architectural concern was considered.
The four surfaces to connect
Keep the human decision in a reviewable source of authority and make the agent-facing representation a projection of it. This prevents prompt files, search indexes and CI configuration from becoming competing versions of the decision.
- Record: versioned decisions with stable identity, lifecycle, rationale and scope.
- Context: concise instructions and read-only retrieval for the current task.
- Control: deterministic checks for consequences that can be tested objectively.
- Evidence: citations, repository state, check results and human approvals preserved with the change.
A repository-native starting point
Start inside one repository rather than designing an organisation-wide platform first. Record a consequential decision, validate it, let agents retrieve it through the Core CLI or read-only MCP server, and add a scoped Sentry rule only when its consequence is mechanically decidable.
AsDecided currently supplies repository-native records, deterministic retrieval and explicitly scoped enforcement. Organisation-wide routing, exception dashboards and health scoring are useful control-plane patterns, but they should be described as additional system design rather than assumed product behaviour.
decided validate decisions/
decided list --status accepted
decided show ADR-0042What a trustworthy control plane should answer
For every proposed change, the system should be able to explain which decisions apply, why they apply, which instructions were supplied, what was checked and what remains a matter for review. Stable citations should lead back to the exact record rather than to an opaque summary generated at query time.