Hexagonal, not by accident

Wireframe capabilities that power mxd

Wireframe is the transport adapter that sits behind mxd's transport port. The domain core defines what it needs — framed request dispatch, streaming bodies, server-initiated push — and Wireframe fulfils those contracts without leaking transport concerns back across the boundary.

Because the adapter owns connection lifecycle, codec selection, and middleware layering, the domain remains testable in isolation: mock the port, exercise the domain, and verify invariants without a running TCP stack. What follows are the adapter-side capabilities that make that contract work.

Compatibility guardrails

WireframeRouter embeds a CompatibilityLayer that orchestrates request-side and reply-side hooks on every routed transaction. On the request path, it decodes XOR-encoded payloads and records the login version. On the reply path, it augments responses with client-specific extras — banner fields for Hotline 1.8.5 and 1.9 clients, omission of those fields for SynHX.

// Request → Compatibility hooks → Domain → Reply hooks
impl CompatibilityLayer {
    fn on_request(&mut self, frame: &mut Frame) {
        if frame.is_xor_encoded() {
            frame.decode_xor();
            self.client_uses_xor = true;
        }
    }
    
    fn on_reply(&self, reply: &mut Frame) {
        if self.client_kind == ClientKind::Hotline185 {
            reply.add_banner_fields();
        }
    }
}

Hook ordering is verified by a spy-based test: on_request → dispatch → on_reply, asserted for both login and non-login transactions. This is the kind of property that looks obvious until someone adds a new route and forgets to wire it through the router. The test exists so that "forgets" becomes "gets a failing CI run."

Architecture diagrams

The architecture page is generated from docs/design.md and the three ADRs. The detailed diagrams and class relationships are pulled from the source documents.