extension-capabilities

The server declares one extension capability, com.example/feature-flags, with a small settings object via server.registerCapabilities({ extensions: { … } }). The client connects once per era leg and asserts the entry and its settings are advertised — by the initialize result on the legacy leg and by server/discover on the modern leg.

pnpm tsx examples/extension-capabilities/client.ts          # modern (server/discover)
pnpm tsx examples/extension-capabilities/client.ts --legacy # 2025 initialize handshake