{"available":true,"algorithm":"ed25519","payloadVersion":"pc1","publicKeyId":"fdf3ef2d04563596","publicKeySpkiBase64":"MCowBQYDK2VwAyEAXBuTyScqlQp6GYwIifP0MCI2ropSf+k4fZ2OAh1tr7E=","publicKeyRawBase64Url":"XBuTyScqlQp6GYwIifP0MCI2ropSf-k4fZ2OAh1tr7E","verify":"ed25519_verify(base64url_decode(signature), utf8(payload), publicKey) — payload is the exact stored string; its `at` must precede the post's publish time for the receipt to prove pre-commitment."}