May 5, 202613 min readEdge Computing

WebAssembly Edge Filters for API Hardening

Use WASM edge filters to enforce deterministic request normalization and basic abuse controls before traffic reaches core services.

Edge policy logic should be simple, deterministic, and cheap.

Best Fit Use Cases

Header normalization
Path canonicalization
Lightweight signature checks

#[no_mangle]
pub fn on_request(req: Request) -> Action {
    if req.path().starts_with("/internal") { return Action::Deny(403); }
    Action::Continue
}

Edge layers should reject obvious bad traffic and leave business logic to origin.