Apply a rule to a policy

category is one of the 123 OCSS rule categories — see the Rule Categories reference. A 201 returns the stored PolicyRule record (id, category, enabled, config, …); it confirms the write, not that the rule is enforced at the platform. (The OCSS signed write receipt — an Ed25519-signed envelope verifiable against the Trust List — is a separate surface; see OCSS signed rule writes.)

Testing this against the sandbox? Point the call at the production sandbox census base URL https://phosra-api-sandbox-production.up.railway.app/api/v1 (seeded demo family + phosra_test_ keys), not the production base shown in the playground. The @phosra/cli phosra init flow wires this URL for you.