Constraint
A rule, boundary, or condition that limits what actions can be taken within an organisation — enforced automatically at the moment of action.
A constraint is a governance boundary that defines what is and is not permissible. Unlike policies (which people read and may or may not follow), constraints are structural: they are checked and enforced at the point of action.
Constraints encode institutional rules as machine-readable conditions. "No expenditure over $10,000 without board approval" is a policy when it lives in a handbook. It becomes a constraint when it is checked automatically every time someone attempts a purchase.
Constraints can be hard (blocking actions that violate them) or soft (flagging actions for review). They can apply to specific domains, roles, or AI agents. The key distinction is that constraints are proactive — they prevent governance failures rather than detecting them after the fact.
How Constellation handles this
Constellation encodes constraints as live governance infrastructure. When an AI agent or human attempts an action, constraints are checked in real time — blocking violations before they occur, not auditing them after.