For agents, on top of README.md, which they read first.

• No retry, timeout or status logic here: that is jev-client's. A send returns the whole response or one TransportError.
• No spend guard here either. A Worker that needs one keeps it in a Durable Object, where every isolate sees the same count.
• Builds for wasm32 only in practice. The native workspace build compiles it but nothing can call it there, so a change is checked with the wasm32 build in the README's "Try it".