# OnionKeySpec.providedV3(_:) Re-adopt a previously-registered v3 service by its private key. ``` case providedV3(String) ``` ## Parameters `key` The ED25519-V3 private key in Tor’s base64-encoded expanded-secret form (rend-spec-v3 §2.5). ## Discussion Corresponds to `ADD_ONION ED25519-V3:` in control-spec.txt §3.27. The blob must be exactly the string Tor handed back in an earlier `ADD_ONION` reply or via `GETINFO onions/current`. > Important: Treat the key as a secret. Persisting it to disk > or logs compromises the onion identity; use Keychain on Apple > platforms.