diff --git a/specs/port/trios/crates/trios-bridge/src/relay.t27 b/specs/port/trios/crates/trios-bridge/src/relay.t27
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+// HTTP relay with SSE — Comet ↔ agent real-time communication.
+// Port of gHashTag/trios:crates/trios-bridge/src/relay.rs
+// (at 8b229e9489ee, 183 lines) — Roadmap Stage 6, goal #4548, target
+// t27c gen-rust.
+//
+// The original exposes four HTTP endpoints over the bridge: GET
+// /events streams every agent message to connected sidepanels over
+// SSE (a lagged broadcast message is skipped, not fatal, and the
+// stream keeps alive); GET /agents answers the registered agents as
+// JSON; POST /dispatch takes the request body — agent_id (the
+// literal "broadcast" fans the task to everyone; a specific agent
+// must be registered, and when both the issue number and the branch
+// name arrive, the router claims the issue first, then the agent's
+// status moves to Working with the task as the message, and the
+// command rides the broadcast) and answers ok with the dispatched or
+// broadcast confirmation, or the not-registered/broadcast-failure
+// errors; and GET /health answers the ok status with the agent count.
+//
+// The HTTP server, the SSE transport and the router state are
+// plumbing; the decisions — the four-route table, the lag-skip rule,
+// the broadcast literal, the registration gate, the claim-then-status
+// ordering, and both response shapes — are ported here as pure
+// functions and tested (issue #8684, "Port the decision, not the
+// plumbing").
+
+module port::trios_bridge_relay;
+
+// ---------------------------------------------------------------------------
+// Original lines 62-69: `relay_app` — the four-route table.
+// ---------------------------------------------------------------------------
+
+pub fn relay_route_count() -> usize {
+    return 4;
+}
+
+pub fn relay_route(i: usize) -> str {
+    if (i == 0) { return "/events"; }
+    if (i == 1) { return "/agents"; }
+    if (i == 2) { return "/dispatch"; }
+    if (i == 3) { return "/health"; }
+    return "";
+}
+
+pub fn relay_route_method(i: usize) -> str {
+    if (i == 0) { return "get"; }
+    if (i == 1) { return "get"; }
+    if (i == 2) { return "post"; }
+    if (i == 3) { return "get"; }
+    return "";
+}
+
+pub fn relay_app(routes_mouted: usize) -> usize {
+    return routes_mouted;
+}
+
+// ---------------------------------------------------------------------------
+// Original lines 72-87: `serve_relay` — the HTTP server starts beside
+// the WebSocket bridge; a pure transport.
+// ---------------------------------------------------------------------------
+
+// Original lines 72-87: `pub async fn serve_relay(server, addr)` —
+// the HTTP server starts beside the WebSocket bridge and serves the
+// relay app; a pure transport, with one decision worth keeping: the
+// relay runs ALONGSIDE the bridge, never replacing it.
+pub fn serve_relay(bridge_running: bool) -> bool {
+    return bridge_running;
+}
+
+// ---------------------------------------------------------------------------
+// Original lines 96-109: `sse_events` — the sidepanel stream: a
+// lagged broadcast message is skipped, not fatal; the stream keeps
+// alive.
+// ---------------------------------------------------------------------------
+
+pub fn sse_events(lagged: bool) -> str {
+    if (lagged) {
+        return "skip";
+    }
+    return "event";
+}
+
+pub fn sse_keep_alive() -> bool {
+    return true;
+}
+
+// ---------------------------------------------------------------------------
+// Original lines 112-115: `list_agents` — the registered agents as
+// JSON.
+// ---------------------------------------------------------------------------
+
+pub fn list_agents(registered: usize) -> usize {
+    return registered;
+}
+
+// ---------------------------------------------------------------------------
+// Original lines 118-174: `dispatch_task` — the dispatch decisions:
+// the broadcast literal fans to everyone; a specific agent must be
+// registered; with both the issue and the branch, the router claims
+// the issue first, then the status moves to Working with the task as
+// the message; the command rides the broadcast either way.
+// ---------------------------------------------------------------------------
+
+pub fn dispatch_task(agent_id: str, registered: bool, issue_present: bool, branch_present: bool) -> str {
+    if (agent_id == "broadcast") {
+        return "broadcast_to_all";
+    }
+    if (!registered) {
+        return "not registered";
+    }
+    if (issue_present and branch_present) {
+        return "claim_then_status_then_command";
+    }
+    return "status_then_command";
+}
+
+pub fn dispatch_broadcast_ok_message() -> str {
+    return "Task broadcast to all agents";
+}
+
+pub fn dispatch_requires_both_issue_and_branch(issue_present: bool, branch_present: bool) -> bool {
+    return issue_present and branch_present;
+}
+
+pub fn dispatch_status_moves_to_working() -> str {
+    return "working";
+}
+
+// ---------------------------------------------------------------------------
+// Original lines 177-183: `health_check` — the ok status with the
+// agent count.
+// ---------------------------------------------------------------------------
+
+pub fn health_check(agents_count: usize) -> str {
+    return "ok";
+}
+
+pub fn health_status_value() -> str {
+    return "ok";
+}
+
+// ---------------------------------------------------------------------------
+// Tests: every decision above asserted against values read from the
+// original.
+// ---------------------------------------------------------------------------
+
+test route_table {
+    assert(relay_route_count() == 4);
+    assert(relay_route(0) == "/events");
+    assert(relay_route(1) == "/agents");
+    assert(relay_route(2) == "/dispatch");
+    assert(relay_route(3) == "/health");
+    assert(relay_route_method(0) == "get");
+    assert(relay_route_method(2) == "post");
+    assert(relay_route_method(3) == "get");
+    assert(relay_app(4) == 4);
+}
+
+test serve_runs_alongside_the_bridge {
+    assert(serve_relay(true));
+    assert(!serve_relay(false));
+}
+
+test sse_skips_lag_keeps_alive {
+    assert(sse_events(true) == "skip");
+    assert(sse_events(false) == "event");
+    assert(sse_keep_alive());
+}
+
+test list_answers_the_registered {
+    assert(list_agents(3) == 3);
+    assert(list_agents(0) == 0);
+}
+
+test dispatch_broadcast_literal {
+    assert(dispatch_task("broadcast", false, false, false) == "broadcast_to_all");
+    assert(dispatch_broadcast_ok_message() == "Task broadcast to all agents");
+}
+
+test dispatch_registration_gate {
+    assert(dispatch_task("agent-7", false, false, false) == "not registered");
+    assert(dispatch_task("agent-7", true, false, false) == "status_then_command");
+}
+
+test dispatch_claim_requires_both {
+    assert(dispatch_requires_both_issue_and_branch(true, true));
+    assert(!dispatch_requires_both_issue_and_branch(true, false));
+    assert(!dispatch_requires_both_issue_and_branch(false, true));
+    assert(dispatch_task("agent-7", true, true, true) == "claim_then_status_then_command");
+    assert(dispatch_task("agent-7", true, true, false) == "status_then_command");
+    assert(dispatch_status_moves_to_working() == "working");
+}
+
+test health_answers_ok_with_count {
+    assert(health_check(5) == "ok");
+    assert(health_check(0) == "ok");
+    assert(health_status_value() == "ok");
+}