feat(trogon-nats): propagate X-Req-Id header across NATS requests

rsworkspace/crates/acp-nats/src/agent/prompt.rs

@@ -11,7 +11,7 @@ use crate::agent::Bridge;
 use crate::nats::{FlushClient, PublishClient, RequestClient, SubscribeClient, agent};
 use crate::session_id::AcpSessionId;
 
-pub const REQ_ID_HEADER: &str = "X-Req-Id";
+pub use trogon_nats::REQ_ID_HEADER;
 
 #[instrument(
     name = "acp.session.prompt",

rsworkspace/crates/trogon-nats/Cargo.toml

@@ -17,6 +17,7 @@ tokio = { workspace = true, features = ["time"] }
 tracing = { workspace = true }
 tracing-opentelemetry = { workspace = true }
 trogon-std = { workspace = true }
+uuid = { workspace = true }
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }

rsworkspace/crates/trogon-nats/src/lib.rs

@@ -50,8 +50,8 @@ pub use client::{FlushClient, PublishClient, RequestClient, SubscribeClient};
 pub use connect::{ConnectError, connect};
 pub use messaging::{
     FlushPolicy, NatsError, PublishOperationError, PublishOptions, PublishOptionsBuilder,
-    RetryPolicy, headers_with_trace_context, inject_trace_context, publish, request,
-    request_with_timeout,
+    REQ_ID_HEADER, RetryPolicy, build_request_headers, headers_with_trace_context,
+    inject_trace_context, publish, request, request_with_timeout,
 };
 
 #[cfg(feature = "test-support")]

rsworkspace/crates/trogon-nats/src/messaging.rs

@@ -23,12 +23,20 @@ pub fn inject_trace_context(headers: &mut HeaderMap) {
     });
 }
 
+pub const REQ_ID_HEADER: &str = "X-Req-Id";
+
 pub fn headers_with_trace_context() -> HeaderMap {
     let mut headers = HeaderMap::new();
     inject_trace_context(&mut headers);
     headers
 }
 
+pub fn build_request_headers() -> HeaderMap {
+    let mut headers = headers_with_trace_context();
+    headers.insert(REQ_ID_HEADER, uuid::Uuid::new_v4().to_string().as_str());
+    headers
+}
+
 pub async fn request_with_timeout<N: RequestClient, Req, Res>(
     client: &N,
     subject: &str,
@@ -40,7 +48,7 @@ where
     Res: DeserializeOwned,
 {
     let payload = serde_json::to_vec(request).map_err(NatsError::Serialize)?;
-    let headers = headers_with_trace_context();
+    let headers = build_request_headers();
 
     let response = tokio::time::timeout(
         timeout,