GAL-2 API-Backed Contract Source Isolation Demonstration: 60-Minute Sustained Mac Client Adoption of a Time Contract-Derived Local SNTP Feed

This evidence package documents a 60-minute sustained operational source-isolation monitor in which a general-purpose Mac client consumed a local SNTP time feed derived from the current GAL-2 Time Contract and backed by the live GAL-2 API. The tested chain was: GAL-2 API -> GAL-2 daemon -> Time Contract -> Mac A SNTP Bridge -> Mac B Network Time This version extends the earlier operational source-isolation demonstration by replacing the prior August 2025 pre-AWS protected local core path with the current API-backed Time Contract path. Mac A acted as the local bridge node, exposing an SNTP-compatible feed derived from the GAL-2 Time Contract. Mac B acted as the client node and was configured to use Mac A as its macOS Network Time Server. Key results: - Mac A IP: 192.168.6.143 - Mac B IP: 192.168.6.243 - Mac B was configured with Network Time: On - Mac B was configured with Network Time Server: 192.168.6.143 - Mac B 60-minute monitor produced 61 samples - Result: PASS - mac_a_gal2_bridge_ok: 61 - network_time_configured_to_mac_a: 61 - mac_a_ref_ids: ["GAL2"] - Mac A bridge served 79 SNTP responses - safe_to_consume=true: 79/79 - Modes observed: LIVE and REJOIN - Monotonic sequence observed from 30284 to 30362 - Source lineage observed: gal2_api > gal2_daemon > contract_v1 - Mac B was restored to time.apple.com after the test - Mac A bridge was stopped after the test - Mac A firewall and stealth mode were restored - No UDP 123 or UDP 9123 listeners remained after closeout Archive included: GAL2_API_Backed_Contract_Source_Isolation_v1_1_60min_MASTER_20260512T173038Z.tar.gz Master archive SHA256: ce63a8e26d38e61ef8d0d1d7e5d101631087f59fb80537fb42e568fcca169f85 Version relationship: This record is a new version of the earlier GAL-2 Operational Source Isolation evidence package. The earlier version documented a prior local protected core path. This version documents the current live API-backed GAL-2 Time Contract path with a sustained 60-minute monitor. Claim boundary: This test supports 60-minute operational source isolation and contract-gated local time consumption using the current GAL-2 Time Contract and live GAL-2 API path. This test does not claim physical oscillator control, metrological replacement of UTC, UTC traceability certification, universal production readiness, or clock accuracy superiority. Project website: https://gal-2.com This record is published for research evidence, timestamping, citation, and technical review. Publication of this evidence package does not grant rights to reproduce, commercialize, reverse engineer, derive, sublicense, or implement GAL-2 core technology, protected formulas, trade secrets, trademarks, or proprietary system architecture.