The term was popularized by Anthropic, whose training method uses a constitution to guide model self-critique and improvement. In enterprise deployment, the concept generalizes: a deployed agent's behavior is bounded by a written policy document that defines scope, prohibitions, escalation rules, and tone.
Training-time constitutional AI and deployment-time agent constitutions are complementary. The model provides a safety floor; the deployment-time constitution adds application-specific rules that the base model cannot know about — your product policies, your compliance posture, your brand voice.
In practice, the deployment-time constitution is enforced at runtime by a policy layer, not just via system prompts, because prompts drift while policies can be audited and versioned.