Gin + GORM + pure-Go SQLite. Users/auth (JWT), API key management with quotas, proxy gateway with weighted channel failover and health checks, usage/billing ledger, cross-protocol conversion (Anthropic Messages / OpenAI Chat Completions / OpenAI Responses), and channel/model admin API. Channels declare native API formats and auto-convert the rest. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>