Checking Server Health

health() does not require authentication and is useful for readiness checks.

import ai.philterd.philter.model.StatusResponse;

StatusResponse status = client.health();
System.out.println(status.getStatus());             // "UP" when Philter is healthy
System.out.println(status.getApplicationVersion()); // e.g. "4.0.0"
System.out.println(status.getRedactionPolicySchemaVersion());
System.out.println(status.getGitCommit());

getSigningKeyDetails() is also unauthenticated. It returns the public key that Philter signs its output with, as PEM and as a JWK, with its fingerprint, so a recipient can verify a signature without credentials. getSigningKeyDetails(keyId) returns a retained key by ID, for verifying output signed with a key that has since been rotated.

SigningKey key = client.getSigningKeyDetails();
String pem = key.getPem();

An administrator can rotate the signing key with regenerateSigningKey(), which requires the signing:write scope. Philter generates a new key and makes it active, and keeps the old one retrievable with getSigningKeyDetails(keyId), so output signed with it stays verifiable. Resolve each signature's key ID rather than caching one key. Where the key is managed by PHILTER_SIGNING_KEY_PATH, rotating over the API is refused with an HTTP 409; replace the file and restart every instance instead.

String activeKeyId = client.regenerateSigningKey();