Introducing Zopa: a 60 KB authorization engine for proxy-wasm, written in Zig

There are plenty of times you want to delegate "let this request through, or block it" to a wasm filter inside Envoy. API gateways, service mesh boundaries, L7 checkpoints. The default move is to use OPA's wasm build. The trouble is OPA-as-wasm is heavy. The Go runtime, the Rego parser, and the evaluator are all in there. You only want to return allow/deny at the edge, but you ship something many times the size of the evaluator. Cedar and Casbin don't ship official wasm builds (as of May 2026).