fix: harden tunnel security and timeout handling

apps/aether-gateway/src/execution_runtime/transport.rs

@@ -38,6 +38,9 @@ use crate::{AppState, GatewayError};
 const HUB_RELAY_CONTENT_TYPE: &str = "application/vnd.aether.tunnel-envelope";
 const HUB_RELAY_ERROR_HEADER: &str = "x-aether-tunnel-error";
 const TUNNEL_RELAY_PATH_PREFIX: &str = "/api/internal/tunnel/relay";
+const DEFAULT_TUNNEL_TIMEOUT_MS: u64 = 60_000;
+const MIN_TUNNEL_TIMEOUT_SECS: u64 = 1;
+const MAX_TUNNEL_TIMEOUT_SECS: u64 = 300;
 pub(crate) fn format_upstream_request_error(err: &reqwest::Error) -> String {
     let mut kinds = Vec::new();
     if err.is_connect() {
@@ -176,6 +179,12 @@ struct RelayRequestMeta {
     method: String,
     url: String,
     headers: BTreeMap<String, String>,
+    #[serde(default, skip_serializing_if = "is_false")]
+    stream: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    request_timeout_ms: Option<u64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    stream_first_byte_timeout_ms: Option<u64>,
     timeout: u64,
     #[serde(skip_serializing_if = "Option::is_none")]
     follow_redirects: Option<bool>,
@@ -195,6 +204,13 @@ pub(crate) struct ExecutionTransportControls {
     accept_invalid_certs: bool,
 }
 
+#[derive(Debug, Clone, Copy)]
+struct TunnelTimeoutMetadata {
+    request_timeout_ms: Option<u64>,
+    stream_first_byte_timeout_ms: Option<u64>,
+    legacy_timeout_secs: u64,
+}
+
 pub(crate) enum DirectUpstreamResponse {
     Reqwest(reqwest::Response),
     BrowserWreq(wreq::Response),
@@ -579,6 +595,7 @@ fn build_direct_tunnel_request_meta(
     headers: &HeaderMap,
     transport_controls: ExecutionTransportControls,
 ) -> tunnel_protocol::RequestMeta {
+    let timeout_metadata = resolve_tunnel_timeout_metadata(plan);
     tunnel_protocol::RequestMeta {
         provider_id: Some(plan.provider_id.clone()),
         endpoint_id: Some(plan.endpoint_id.clone()),
@@ -586,7 +603,10 @@ fn build_direct_tunnel_request_meta(
         method: plan.method.clone(),
         url: plan.url.clone(),
         headers: header_map_to_string_map(headers).into_iter().collect(),
-        timeout: resolve_relay_timeout_seconds(plan),
+        stream: plan.stream,
+        request_timeout_ms: timeout_metadata.request_timeout_ms,
+        stream_first_byte_timeout_ms: timeout_metadata.stream_first_byte_timeout_ms,
+        timeout: timeout_metadata.legacy_timeout_secs,
         follow_redirects: transport_controls.follow_redirects,
         http1_only: transport_controls.http1_only,
         transport_profile: plan.transport_profile.clone(),
@@ -753,7 +773,8 @@ async fn send_via_tunnel_relay(
 ) -> Result<reqwest::Response, ExecutionRuntimeTransportError> {
     let client = build_relay_client(plan.timeouts.as_ref())?;
     let relay_url = build_relay_url(plan.proxy.as_ref(), node_id);
-    let timeout_secs = resolve_relay_timeout_seconds(plan);
+    let timeout_metadata = resolve_tunnel_timeout_metadata(plan);
+    let timeout_secs = timeout_metadata.legacy_timeout_secs;
     let envelope = build_relay_envelope(
         RelayRequestMeta {
             provider_id: plan.provider_id.clone(),
@@ -762,6 +783,9 @@ async fn send_via_tunnel_relay(
             method: method.as_str().to_string(),
             url: plan.url.clone(),
             headers: header_map_to_string_map(&headers),
+            stream: plan.stream,
+            request_timeout_ms: timeout_metadata.request_timeout_ms,
+            stream_first_byte_timeout_ms: timeout_metadata.stream_first_byte_timeout_ms,
             timeout: timeout_secs,
             follow_redirects: transport_controls.follow_redirects,
             http1_only: transport_controls.http1_only,
@@ -791,15 +815,22 @@ async fn send_via_tunnel_relay(
         .request(reqwest::Method::POST, relay_url)
         .header(reqwest::header::CONTENT_TYPE, HUB_RELAY_CONTENT_TYPE)
         .body(envelope);
-    if let Some(timeout) = total_timeout {
+    if !plan.stream {
-        request = request.timeout(timeout);
+        if let Some(timeout) = total_timeout {
+            request = request.timeout(timeout);
+        }
     }
 
+    let first_byte_timeout = if plan.stream {
+        resolve_tunnel_first_byte_timeout(plan)
+    } else {
+        None
+    };
+
     let started_at = Instant::now();
-    let response = request
+    let response = send_relay_request(request, first_byte_timeout)
-        .send()
         .await
-        .map_err(|err| ExecutionRuntimeTransportError::RelayError(err.to_string()))?;
+        .map_err(ExecutionRuntimeTransportError::RelayError)?;
     let elapsed_ms = started_at.elapsed().as_millis() as u64;
     let status_code = response.status().as_u16();
     let proxy_timing = response
@@ -869,6 +900,21 @@ async fn send_via_tunnel_relay(
     Ok(response)
 }
 
+async fn send_relay_request(
+    request: reqwest::RequestBuilder,
+    first_byte_timeout: Option<Duration>,
+) -> Result<reqwest::Response, String> {
+    if let Some(timeout) = first_byte_timeout {
+        return match tokio::time::timeout(timeout, request.send()).await {
+            Ok(Ok(response)) => Ok(response),
+            Ok(Err(error)) => Err(error.to_string()),
+            Err(_) => Err("tunnel relay first byte timeout".to_string()),
+        };
+    }
+
+    request.send().await.map_err(|err| err.to_string())
+}
+
 pub(crate) fn build_request_body(
     plan: &ExecutionPlan,
 ) -> Result<Vec<u8>, ExecutionRuntimeTransportError> {
@@ -965,18 +1011,49 @@ fn resolve_tunnel_base_url_from_proxy(proxy: &ProxySnapshot) -> Option<String> {
 }
 
 fn resolve_relay_timeout_seconds(plan: &ExecutionPlan) -> u64 {
-    let ms = plan
+    resolve_tunnel_timeout_metadata(plan).legacy_timeout_secs
-        .timeouts
+}
+
+fn resolve_tunnel_first_byte_timeout(plan: &ExecutionPlan) -> Option<Duration> {
+    plan.stream.then(|| {
+        Duration::from_millis(
+            resolve_selected_tunnel_timeout_ms(plan).unwrap_or(DEFAULT_TUNNEL_TIMEOUT_MS),
+        )
+    })
+}
+
+fn resolve_tunnel_timeout_metadata(plan: &ExecutionPlan) -> TunnelTimeoutMetadata {
+    TunnelTimeoutMetadata {
+        request_timeout_ms: plan
+            .timeouts
+            .as_ref()
+            .and_then(|timeouts| timeouts.total_ms),
+        stream_first_byte_timeout_ms: plan
+            .timeouts
+            .as_ref()
+            .and_then(|timeouts| timeouts.first_byte_ms),
+        legacy_timeout_secs: timeout_ms_to_secs(
+            resolve_selected_tunnel_timeout_ms(plan).unwrap_or(DEFAULT_TUNNEL_TIMEOUT_MS),
+        ),
+    }
+}
+
+fn resolve_selected_tunnel_timeout_ms(plan: &ExecutionPlan) -> Option<u64> {
+    plan.timeouts
         .as_ref()
         .and_then(|timeouts| {
-            timeouts
+            if plan.stream {
-                .read_ms
+                timeouts.first_byte_ms.or(timeouts.total_ms)
-                .or(timeouts.total_ms)
+            } else {
-                .or(timeouts.connect_ms)
+                timeouts.total_ms.or(timeouts.first_byte_ms)
+            }
         })
-        .unwrap_or(60_000);
+        .map(|value| value.max(1))
+}
+
+fn timeout_ms_to_secs(ms: u64) -> u64 {
     let secs = ms.div_ceil(1_000);
-    secs.clamp(1, 300)
+    secs.clamp(MIN_TUNNEL_TIMEOUT_SECS, MAX_TUNNEL_TIMEOUT_SECS)
 }
 
 fn resolve_tunnel_node_id(proxy: Option<&ProxySnapshot>) -> Option<String> {
@@ -1522,12 +1599,12 @@ mod tests {
     use tokio::sync::watch;
 
     use super::{
-        build_browser_wreq_client, build_client, build_execution_response_body,
+        build_browser_wreq_client, build_client, build_direct_tunnel_request_meta,
-        build_request_headers, execute_sync_plan, record_manual_proxy_request_failure,
+        build_execution_response_body, build_request_headers, execute_sync_plan,
-        record_manual_proxy_request_outcome, record_manual_proxy_request_success,
+        record_manual_proxy_request_failure, record_manual_proxy_request_outcome,
-        record_manual_proxy_stream_error, resolve_execution_transport_controls,
+        record_manual_proxy_request_success, record_manual_proxy_stream_error,
-        response_body_is_json, DirectSyncExecutionRuntime, ExecutionRuntimeTransportError,
+        resolve_execution_transport_controls, response_body_is_json, DirectSyncExecutionRuntime,
-        ExecutionTransportControls,
+        ExecutionRuntimeTransportError, ExecutionTransportControls,
     };
     use crate::constants::{
         EXECUTION_RUNTIME_LOOP_GUARD_HEADER, EXECUTION_RUNTIME_LOOP_GUARD_VIA_TOKEN,
@@ -1629,6 +1706,64 @@ mod tests {
             .is_none());
     }
 
+    #[test]
+    fn tunnel_request_meta_uses_total_timeout_for_non_stream_requests() {
+        let plan = tunnel_timeout_plan(false);
+        let meta = build_direct_tunnel_request_meta(
+            &plan,
+            &reqwest::header::HeaderMap::new(),
+            ExecutionTransportControls::default(),
+        );
+
+        assert!(!meta.stream);
+        assert_eq!(meta.request_timeout_ms, Some(90_000));
+        assert_eq!(meta.stream_first_byte_timeout_ms, Some(12_345));
+        assert_eq!(meta.timeout, 90);
+    }
+
+    #[test]
+    fn tunnel_request_meta_uses_first_byte_timeout_for_stream_requests() {
+        let plan = tunnel_timeout_plan(true);
+        let meta = build_direct_tunnel_request_meta(
+            &plan,
+            &reqwest::header::HeaderMap::new(),
+            ExecutionTransportControls::default(),
+        );
+
+        assert!(meta.stream);
+        assert_eq!(meta.request_timeout_ms, Some(90_000));
+        assert_eq!(meta.stream_first_byte_timeout_ms, Some(12_345));
+        assert_eq!(meta.timeout, 13);
+    }
+
+    fn tunnel_timeout_plan(stream: bool) -> ExecutionPlan {
+        ExecutionPlan {
+            request_id: "req-timeout".into(),
+            candidate_id: None,
+            provider_name: Some("provider".into()),
+            provider_id: "prov-1".into(),
+            endpoint_id: "ep-1".into(),
+            key_id: "key-1".into(),
+            method: "POST".into(),
+            url: "https://example.com/chat".into(),
+            headers: BTreeMap::from([("content-type".into(), "application/json".into())]),
+            content_type: Some("application/json".into()),
+            content_encoding: None,
+            body: RequestBody::from_json(json!({"model": "gpt-4.1"})),
+            stream,
+            client_api_format: "openai:chat".into(),
+            provider_api_format: "openai:chat".into(),
+            model_name: Some("gpt-4.1".into()),
+            proxy: None,
+            transport_profile: None,
+            timeouts: Some(ExecutionTimeouts {
+                total_ms: Some(90_000),
+                first_byte_ms: Some(12_345),
+                ..ExecutionTimeouts::default()
+            }),
+        }
+    }
+
     fn tunnel_proxy_snapshot(base_url: String) -> ProxySnapshot {
         ProxySnapshot {
             enabled: Some(true),

apps/aether-gateway/src/handlers/admin/system/proxy_nodes.rs

@@ -1374,6 +1374,9 @@ fn build_tunnel_probe_relay_envelope(
         method: "GET".to_string(),
         url: probe_url.trim().to_string(),
         headers: std::collections::HashMap::new(),
+        stream: false,
+        request_timeout_ms: None,
+        stream_first_byte_timeout_ms: None,
         timeout: timeout_secs,
         follow_redirects: Some(false),
         http1_only: false,

apps/aether-gateway/src/tunnel/embedded/hub.rs

@@ -1307,6 +1307,9 @@ mod tests {
             method: "GET".to_string(),
             url: "https://example.com".to_string(),
             headers: HashMap::new(),
+            stream: false,
+            request_timeout_ms: None,
+            stream_first_byte_timeout_ms: None,
             timeout: 30,
             follow_redirects: None,
             http1_only: false,

apps/aether-gateway/src/tunnel/embedded/local_relay.rs

@@ -24,6 +24,8 @@ use super::AppState;
 
 pub const TUNNEL_ERROR_HEADER: &str = "x-aether-tunnel-error";
 const MAX_RELAY_META_LEN: usize = 256 * 1024;
+const MIN_RELAY_TIMEOUT_MS: u64 = 1;
+const MAX_RELAY_TIMEOUT_MS: u64 = 300_000;
 
 struct StreamGuard {
     hub: std::sync::Arc<super::hub::HubRouter>,
@@ -92,7 +94,7 @@ pub(crate) async fn open_direct_relay_stream(
         return Err(format!("connect: {error}"));
     }
 
-    let wait_timeout = Duration::from_secs(meta.timeout.clamp(5, 300));
+    let wait_timeout = relay_header_timeout(&meta);
     let response_head = match stream.wait_headers(wait_timeout).await {
         Ok(response) => response,
         Err(error) => {
@@ -148,6 +150,19 @@ fn map_request_admission_error(error: super::RequestAdmissionError) -> String {
     }
 }
 
+fn relay_header_timeout(meta: &protocol::RequestMeta) -> Duration {
+    let timeout_ms = if meta.stream {
+        meta.stream_first_byte_timeout_ms
+            .or(meta.request_timeout_ms)
+            .unwrap_or_else(|| meta.timeout.saturating_mul(1_000))
+    } else {
+        meta.request_timeout_ms
+            .or(meta.stream_first_byte_timeout_ms)
+            .unwrap_or_else(|| meta.timeout.saturating_mul(1_000))
+    };
+    Duration::from_millis(timeout_ms.clamp(MIN_RELAY_TIMEOUT_MS, MAX_RELAY_TIMEOUT_MS))
+}
+
 pub async fn relay_request(
     Path(node_id): Path<String>,
     State(state): State<AppState>,
@@ -322,7 +337,7 @@ pub async fn relay_request(
         finished: false,
     };
 
-    let wait_timeout = Duration::from_secs(meta.timeout.clamp(5, 300));
+    let wait_timeout = relay_header_timeout(&meta);
     let response_head = match stream.wait_headers(wait_timeout).await {
         Ok(response) => response,
         Err(error) => {
@@ -639,6 +654,9 @@ mod tests {
             method: "GET".to_string(),
             url: "https://example.com/health".to_string(),
             headers: HashMap::new(),
+            stream: false,
+            request_timeout_ms: None,
+            stream_first_byte_timeout_ms: None,
             timeout: 30,
             follow_redirects: None,
             http1_only: false,
@@ -754,6 +772,9 @@ mod tests {
             method: "GET".to_string(),
             url: "https://example.com/headers".to_string(),
             headers: HashMap::new(),
+            stream: false,
+            request_timeout_ms: None,
+            stream_first_byte_timeout_ms: None,
             timeout: 30,
             follow_redirects: None,
             http1_only: false,

apps/aether-gateway/src/tunnel/mod.rs

@@ -519,6 +519,9 @@ impl EmbeddedTunnelState {
             method: "GET".to_string(),
             url: url.trim().to_string(),
             headers: HashMap::new(),
+            stream: false,
+            request_timeout_ms: None,
+            stream_first_byte_timeout_ms: None,
             timeout: timeout_secs,
             follow_redirects: Some(false),
             http1_only: false,

apps/aether-tunnel/README.md

@@ -229,7 +229,7 @@ node_name = "jp-proxy-02"
 tunnel_encryption_key = "base64-32-bytes"
 ```
 
-`tunnel_security = "non_tls_required"` 是非 TLS secure tunnel 的 MVP 配置面：它要求同时提供当前 `[[servers]]` 条目的 `tunnel_encryption_key`，后续握手使用 `node_name` / `X-Node-Id` 查找对应 PSK，不引入 `tunnel_encryption_key_id`。`wss://` 仍是推荐方案；`ws:// + secure tunnel` 只保护 Aether ↔ tunnel 之间的 token 和 payload，不等价于 HTTPS 伪装，也不覆盖 tunnel ↔ origin/provider 这段链路。
+`tunnel_security = "non_tls_required"` 是非 TLS secure tunnel 的 MVP 配置面：它要求同时提供当前 `[[servers]]` 条目的 `tunnel_encryption_key`，后续握手使用 `node_name` / `X-Node-Id` 查找对应 PSK，不引入 `tunnel_encryption_key_id`。`wss://` 仍是推荐方案；`ws:// + secure tunnel` 只加密注册完成后的 WebSocket tunnel frame，不保护安装脚本、注册请求、`management_token` 或 PSK 的首次分发；这些 bootstrap 凭据仍必须通过 HTTPS 或其他可信通道交付。它不等价于 HTTPS 伪装，也不覆盖 tunnel ↔ origin/provider 这段链路。
 
 如果 `aether_url` 使用 `http://` 且当前 `[[servers]]` 条目提供了 `tunnel_encryption_key`，省略 `tunnel_security` 时运行时会自动按 `non_tls_required` 生效；显式配置 `tunnel_security = "off"` 会关闭该自动推断。secure tunnel 会在 WebSocket tunnel 上加密所有二进制 tunnel frame；未配置 key 或显式关闭的旧节点仍按原明文协议工作。
 

apps/aether-tunnel/src/app.rs

@@ -221,6 +221,13 @@ pub async fn run(mut config: Config, servers: Vec<ServerEntry>) -> anyhow::Resul
             entry.tunnel_encryption_key.as_deref(),
         );
         if tunnel_security == crate::config::TunnelSecurity::NonTlsRequired {
+            if entry.aether_url.trim_start().starts_with("http://") {
+                warn!(
+                    server = %label,
+                    url = %entry.aether_url,
+                    "secure tunnel frame encryption starts after registration; deliver install and registration credentials over HTTPS or another trusted bootstrap channel"
+                );
+            }
             let key = entry
                 .tunnel_encryption_key
                 .as_deref()

apps/aether-tunnel/src/tunnel/mod.rs

@@ -392,6 +392,9 @@ mod tests {
             method: "GET".to_string(),
             url: "http://127.0.0.1:80/blocked".to_string(),
             headers: std::collections::HashMap::new(),
+            stream: false,
+            request_timeout_ms: None,
+            stream_first_byte_timeout_ms: None,
             timeout: 5,
             follow_redirects: None,
             http1_only: false,

apps/aether-tunnel/src/tunnel/stream_handler.rs

@@ -39,10 +39,10 @@ const SLOW_STREAM_LOG_THRESHOLD: Duration = Duration::from_secs(2);
 const SUCCESS_LOG_SAMPLE_MODULO: u32 = 256;
 const REQUEST_BODY_SPOOL_QUEUE_CAPACITY: usize = 64;
 
-/// Minimum allowed upstream request timeout (seconds).
+/// Minimum allowed upstream request timeout (milliseconds).
-const MIN_TIMEOUT_SECS: u64 = 5;
+const MIN_TIMEOUT_MS: u64 = 1;
-/// Maximum allowed upstream request timeout (seconds).
+/// Maximum allowed upstream request timeout (milliseconds).
-const MAX_TIMEOUT_SECS: u64 = 300;
+const MAX_TIMEOUT_MS: u64 = 300_000;
 /// Match reqwest's default redirect budget so direct execution and tunnel relay
 /// fail at the same point instead of diverging after a different number of hops.
 const MAX_REDIRECTS: usize = 10;
@@ -95,6 +95,12 @@ struct PreparedRequestBody {
     replay_body: ReplayableRequestBody,
 }
 
+#[derive(Debug, Clone, Copy)]
+struct RequestTimeouts {
+    first_byte_timeout: Duration,
+    response_body_timeout: Option<Duration>,
+}
+
 #[derive(Debug)]
 struct RequestBodyReplayState {
     budget_bytes: usize,
@@ -588,6 +594,45 @@ fn remaining_timeout(deadline: Instant) -> Option<Duration> {
     deadline.checked_duration_since(Instant::now())
 }
 
+fn resolve_request_timeouts(meta: &RequestMeta) -> RequestTimeouts {
+    let first_byte_timeout = if meta.stream {
+        meta.stream_first_byte_timeout_ms
+            .or(meta.request_timeout_ms)
+            .map(timeout_duration_from_ms)
+            .unwrap_or_else(|| timeout_duration_from_legacy_secs(meta.timeout))
+    } else {
+        meta.request_timeout_ms
+            .or(meta.stream_first_byte_timeout_ms)
+            .map(timeout_duration_from_ms)
+            .unwrap_or_else(|| timeout_duration_from_legacy_secs(meta.timeout))
+    };
+
+    let response_body_timeout = if meta.stream {
+        None
+    } else {
+        Some(
+            meta.request_timeout_ms
+                .or(meta.stream_first_byte_timeout_ms)
+                .map(timeout_duration_from_ms)
+                .unwrap_or_else(|| timeout_duration_from_legacy_secs(meta.timeout)),
+        )
+    };
+
+    RequestTimeouts {
+        first_byte_timeout,
+        response_body_timeout,
+    }
+}
+
+fn timeout_duration_from_ms(ms: u64) -> Duration {
+    Duration::from_millis(ms.clamp(MIN_TIMEOUT_MS, MAX_TIMEOUT_MS))
+}
+
+fn timeout_duration_from_legacy_secs(secs: u64) -> Duration {
+    let ms = secs.saturating_mul(1_000);
+    timeout_duration_from_ms(ms)
+}
+
 async fn spool_request_body(
     mut body_rx: mpsc::Receiver<TunnelFrame>,
     mut spool_tx: mpsc::Sender<SpoolBodyEvent>,
@@ -888,7 +933,7 @@ async fn relay_upstream_response<B>(
     redirect_count: usize,
     request_body_mode: &'static str,
     emit_proxy_timing_header: bool,
-    deadline: Instant,
+    response_body_deadline: Option<Instant>,
 ) -> Option<Duration>
 where
     B: hyper::body::Body<Data = Bytes> + Send + Unpin + 'static,
@@ -956,28 +1001,8 @@ where
 
     let mut stream = response.into_body().into_data_stream();
     loop {
-        let Some(remaining) = remaining_timeout(deadline) else {
+        let chunk_result = if let Some(deadline) = response_body_deadline {
-            server.metrics.stream_errors.fetch_add(1, Ordering::Release);
+            let Some(remaining) = remaining_timeout(deadline) else {
-            let error_message = "upstream response body timeout".to_string();
-            log_stream_failure(
-                stream_log_context(
-                    server,
-                    stream_id,
-                    method,
-                    Some(request_url),
-                    redirect_count,
-                    request_body_size.load(Ordering::Relaxed),
-                ),
-                &error_message,
-                total_elapsed,
-            );
-            send_error(frame_tx, stream_id, &error_message).await;
-            return Some(total_elapsed);
-        };
-
-        let chunk_result = match tokio::time::timeout(remaining, stream.next()).await {
-            Ok(chunk_result) => chunk_result,
-            Err(_) => {
                 server.metrics.stream_errors.fetch_add(1, Ordering::Release);
                 let error_message = "upstream response body timeout".to_string();
                 log_stream_failure(
@@ -994,7 +1019,31 @@ where
                 );
                 send_error(frame_tx, stream_id, &error_message).await;
                 return Some(total_elapsed);
+            };
+
+            match tokio::time::timeout(remaining, stream.next()).await {
+                Ok(chunk_result) => chunk_result,
+                Err(_) => {
+                    server.metrics.stream_errors.fetch_add(1, Ordering::Release);
+                    let error_message = "upstream response body timeout".to_string();
+                    log_stream_failure(
+                        stream_log_context(
+                            server,
+                            stream_id,
+                            method,
+                            Some(request_url),
+                            redirect_count,
+                            request_body_size.load(Ordering::Relaxed),
+                        ),
+                        &error_message,
+                        total_elapsed,
+                    );
+                    send_error(frame_tx, stream_id, &error_message).await;
+                    return Some(total_elapsed);
+                }
             }
+        } else {
+            stream.next().await
         };
 
         let Some(chunk_result) = chunk_result else {
@@ -1272,16 +1321,19 @@ async fn handle_stream_inner(
         }
     }
 
-    let deadline = Instant::now()
+    let overall_start = Instant::now();
-        + Duration::from_secs(meta.timeout.clamp(MIN_TIMEOUT_SECS, MAX_TIMEOUT_SECS));
+    let request_timeouts = resolve_request_timeouts(&meta);
+    let first_byte_deadline = overall_start + request_timeouts.first_byte_timeout;
+    let response_body_deadline = request_timeouts
+        .response_body_timeout
+        .map(|timeout| overall_start + timeout);
     let follow_redirects = follow_redirects_enabled(&meta);
     let mut current_headers = sanitize_upstream_headers(&meta.headers);
-    let timeout = Duration::from_secs(meta.timeout.clamp(MIN_TIMEOUT_SECS, MAX_TIMEOUT_SECS));
+    let first_byte_timeout = request_timeouts.first_byte_timeout;
     let request_body_size = Arc::new(AtomicUsize::new(0));
     let request_has_body = request_likely_has_body(&current_method, &meta.headers);
     let replay_budget_bytes = state.config.redirect_replay_budget_bytes;
     let can_buffer_redirect_body = request_has_body && follow_redirects && replay_budget_bytes > 0;
-    let overall_start = Instant::now();
     let request_body_mode = if can_buffer_redirect_body {
         "buffered_fixed"
     } else if request_has_body {
@@ -1293,7 +1345,7 @@ async fn handle_stream_inner(
         let buffered_body = match collect_request_body_for_replay(
             body_rx,
             Arc::clone(&request_body_size),
-            deadline,
+            first_byte_deadline,
             replay_budget_bytes,
         )
         .await
@@ -1321,7 +1373,12 @@ async fn handle_stream_inner(
             replay_body: replay_body_from_buffered(buffered_body, replay_budget_bytes),
         }
     } else if request_has_body {
-        prepare_request_body(body_rx, Arc::clone(&request_body_size), deadline, 0)
+        prepare_request_body(
+            body_rx,
+            Arc::clone(&request_body_size),
+            first_byte_deadline,
+            0,
+        )
     } else {
         PreparedRequestBody {
             first_request_body: Some(build_streaming_request_body(
@@ -1341,7 +1398,7 @@ async fn handle_stream_inner(
     let mut next_request_body = None::<upstream_client::UpstreamRequestBody>;
 
     loop {
-        let Some(remaining) = remaining_timeout(deadline) else {
+        let Some(remaining) = remaining_timeout(first_byte_deadline) else {
             log_stream_failure(
                 stream_log_context(
                     server,
@@ -1369,7 +1426,7 @@ async fn handle_stream_inner(
             current_method.clone(),
             &current_headers,
             request_body,
-            remaining.min(timeout),
+            remaining.min(first_byte_timeout),
             meta.http1_only,
         )
         .await
@@ -1419,7 +1476,7 @@ async fn handle_stream_inner(
                         redirects_followed,
                         request_body_mode,
                         state.config.emit_proxy_timing_header,
-                        deadline,
+                        response_body_deadline,
                     )
                     .await;
                 }
@@ -1431,7 +1488,7 @@ async fn handle_stream_inner(
                 } => match prepare_redirect_request_body(
                     prepared_body.replay_body.clone(),
                     body_mode,
-                    deadline,
+                    first_byte_deadline,
                 )
                 .await
                 {
@@ -1459,7 +1516,7 @@ async fn handle_stream_inner(
                             redirects_followed,
                             request_body_mode,
                             state.config.emit_proxy_timing_header,
-                            deadline,
+                            response_body_deadline,
                         )
                         .await;
                     }
@@ -1515,7 +1572,7 @@ async fn handle_stream_inner(
             redirects_followed,
             request_body_mode,
             state.config.emit_proxy_timing_header,
-            deadline,
+            response_body_deadline,
         )
         .await;
     }
@@ -1850,6 +1907,34 @@ mod tests {
         );
     }
 
+    #[test]
+    fn stream_request_timeouts_use_first_byte_without_response_body_deadline() {
+        let mut meta = sample_request_meta();
+        meta.stream = true;
+        meta.request_timeout_ms = Some(90_000);
+        meta.stream_first_byte_timeout_ms = Some(12_345);
+
+        let timeouts = resolve_request_timeouts(&meta);
+
+        assert_eq!(timeouts.first_byte_timeout, Duration::from_millis(12_345));
+        assert!(timeouts.response_body_timeout.is_none());
+    }
+
+    #[test]
+    fn non_stream_request_timeouts_use_total_for_response_body_deadline() {
+        let mut meta = sample_request_meta();
+        meta.request_timeout_ms = Some(90_000);
+        meta.stream_first_byte_timeout_ms = Some(12_345);
+
+        let timeouts = resolve_request_timeouts(&meta);
+
+        assert_eq!(timeouts.first_byte_timeout, Duration::from_millis(90_000));
+        assert_eq!(
+            timeouts.response_body_timeout,
+            Some(Duration::from_millis(90_000))
+        );
+    }
+
     #[test]
     fn resolve_redirect_changes_post_to_get_for_302() {
         let current_url = url::Url::parse("https://redirect.test/start").expect("url");
@@ -2073,7 +2158,7 @@ mod tests {
             0,
             "empty",
             true,
-            Instant::now(),
+            Some(Instant::now()),
         )
         .await;
 
@@ -2086,6 +2171,51 @@ mod tests {
         assert_eq!(server.metrics.stream_errors.load(Ordering::Acquire), 1);
     }
 
+    #[tokio::test]
+    async fn stream_response_body_without_total_deadline_allows_late_chunk() {
+        let state = sample_state(None, None);
+        let server = sample_server(&state);
+        let (frame_tx, sent, writer_handle) = spawn_test_writer();
+        let request_url = url::Url::parse("https://example.com/stream").expect("url");
+        let request_body_size = AtomicUsize::new(0);
+        let body = Body::from_stream(stream::once(async {
+            tokio::time::sleep(Duration::from_millis(10)).await;
+            Ok::<Bytes, std::convert::Infallible>(Bytes::from_static(b"late"))
+        }));
+        let response = Response::builder()
+            .status(StatusCode::OK)
+            .body(body)
+            .expect("response");
+
+        relay_upstream_response(
+            &server,
+            14,
+            &hyper::Method::GET,
+            &request_url,
+            &frame_tx,
+            response,
+            0,
+            Duration::ZERO,
+            upstream_client::RequestTiming::default(),
+            &request_body_size,
+            0,
+            "empty",
+            true,
+            None,
+        )
+        .await;
+
+        let result = collect_stream_result(frame_tx, sent, writer_handle).await;
+        assert!(
+            result.error.is_none(),
+            "unexpected error: {:?}",
+            result.error
+        );
+        assert_eq!(result.response.expect("response metadata").status, 200);
+        assert_eq!(result.body, Bytes::from_static(b"late"));
+        assert_eq!(server.metrics.stream_errors.load(Ordering::Acquire), 0);
+    }
+
     #[tokio::test]
     async fn follows_redirects_when_explicitly_enabled_for_replayable_post_requests() {
         let listener = tokio::net::TcpListener::bind("127.0.0.1:0")
@@ -2427,6 +2557,9 @@ mod tests {
             method: "GET".to_string(),
             url: "https://example.com/ok".to_string(),
             headers: HashMap::new(),
+            stream: false,
+            request_timeout_ms: None,
+            stream_first_byte_timeout_ms: None,
             timeout: 30,
             follow_redirects: None,
             http1_only: false,

crates/aether-contracts/src/tunnel.rs

@@ -185,6 +185,12 @@ pub struct RequestMeta {
     pub method: String,
     pub url: String,
     pub headers: std::collections::HashMap<String, String>,
+    #[serde(default, skip_serializing_if = "is_false")]
+    pub stream: bool,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub request_timeout_ms: Option<u64>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub stream_first_byte_timeout_ms: Option<u64>,
     #[serde(default = "default_timeout", deserialize_with = "deserialize_timeout")]
     pub timeout: u64,
     #[serde(default, skip_serializing_if = "Option::is_none")]

crates/aether-contracts/src/tunnel_security.rs

@@ -39,6 +39,8 @@ pub enum TunnelSecurityError {
     MissingEncryptedFlag,
     #[error("secure tunnel frame payload is too short")]
     PayloadTooShort,
+    #[error("secure tunnel frame sequence is not the expected next value")]
+    UnexpectedSequence,
     #[error("secure tunnel frame encryption failed")]
     Encrypt,
     #[error("secure tunnel frame decryption failed")]
@@ -51,6 +53,7 @@ pub struct SecureFrameCodec {
     seal_prefix: [u8; 4],
     open_prefix: [u8; 4],
     next_sequence: AtomicU64,
+    next_open_sequence: AtomicU64,
 }
 
 impl SecureFrameCodec {
@@ -90,6 +93,7 @@ impl SecureFrameCodec {
             seal_prefix,
             open_prefix,
             next_sequence: AtomicU64::new(0),
+            next_open_sequence: AtomicU64::new(0),
         })
     }
 
@@ -132,6 +136,10 @@ impl SecureFrameCodec {
 
         let mut payload = frame.payload.clone();
         let sequence = payload.get_u64();
+        let expected_sequence = self.next_open_sequence.load(Ordering::Relaxed);
+        if sequence != expected_sequence {
+            return Err(TunnelSecurityError::UnexpectedSequence);
+        }
         let nonce_bytes = nonce_bytes(self.open_prefix, sequence);
         let nonce = Nonce::from_slice(&nonce_bytes);
         let clear_flags = frame.flags & !FLAG_ENCRYPTED;
@@ -146,6 +154,8 @@ impl SecureFrameCodec {
                 },
             )
             .map_err(|_| TunnelSecurityError::Decrypt)?;
+        self.next_open_sequence
+            .store(expected_sequence.wrapping_add(1), Ordering::Relaxed);
 
         Ok(Frame::new(
             frame.stream_id,
@@ -243,6 +253,68 @@ mod tests {
         ));
     }
 
+    #[test]
+    fn secure_frame_rejects_replayed_sequence() {
+        let client = SecureFrameCodec::new(&test_key(), "session-1", TunnelSecurityRole::Client)
+            .expect("client codec");
+        let server = SecureFrameCodec::new(&test_key(), "session-1", TunnelSecurityRole::Server)
+            .expect("server codec");
+        let encrypted = client
+            .encrypt_frame(Frame::new(
+                1,
+                MsgType::RequestBody,
+                0,
+                Bytes::from_static(b"secret"),
+            ))
+            .expect("encrypt");
+        let wire = Frame::decode(encrypted).expect("wire frame");
+
+        server.decrypt_frame(wire.clone()).expect("first decrypt");
+        assert!(matches!(
+            server.decrypt_frame(wire),
+            Err(TunnelSecurityError::UnexpectedSequence)
+        ));
+    }
+
+    #[test]
+    fn secure_frame_rejects_out_of_order_sequence_without_advancing() {
+        let client = SecureFrameCodec::new(&test_key(), "session-1", TunnelSecurityRole::Client)
+            .expect("client codec");
+        let server = SecureFrameCodec::new(&test_key(), "session-1", TunnelSecurityRole::Server)
+            .expect("server codec");
+        let first = Frame::decode(
+            client
+                .encrypt_frame(Frame::new(
+                    1,
+                    MsgType::RequestBody,
+                    0,
+                    Bytes::from_static(b"first"),
+                ))
+                .expect("encrypt first"),
+        )
+        .expect("first wire frame");
+        let second = Frame::decode(
+            client
+                .encrypt_frame(Frame::new(
+                    1,
+                    MsgType::RequestBody,
+                    0,
+                    Bytes::from_static(b"second"),
+                ))
+                .expect("encrypt second"),
+        )
+        .expect("second wire frame");
+
+        assert!(matches!(
+            server.decrypt_frame(second),
+            Err(TunnelSecurityError::UnexpectedSequence)
+        ));
+        assert_eq!(
+            server.decrypt_frame(first).expect("first decrypt").payload,
+            Bytes::from_static(b"first")
+        );
+    }
+
     #[test]
     fn secure_frame_uses_session_in_key_derivation() {
         let session_a = "node-1:connection-a";

crates/aether-data/src/repository/proxy_nodes/memory.rs

@@ -9,11 +9,12 @@ use uuid::Uuid;
 use super::types::{
     bucket_start_unix_secs, build_tunnel_error_event_detail, build_tunnel_metrics_sample,
     log_reported_tunnel_error_event, normalize_proxy_metadata,
-    reconcile_remote_config_after_heartbeat, ProxyNodeEventQuery, ProxyNodeHeartbeatMutation,
+    preserve_proxy_metadata_tunnel_security, reconcile_remote_config_after_heartbeat,
-    ProxyNodeManualCreateMutation, ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary,
+    ProxyNodeEventQuery, ProxyNodeHeartbeatMutation, ProxyNodeManualCreateMutation,
-    ProxyNodeMetricsStep, ProxyNodeReadRepository, ProxyNodeRegistrationMutation,
+    ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary, ProxyNodeMetricsStep,
-    ProxyNodeRemoteConfigMutation, ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation,
+    ProxyNodeReadRepository, ProxyNodeRegistrationMutation, ProxyNodeRemoteConfigMutation,
-    ProxyNodeWriteRepository, StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
+    ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation, ProxyNodeWriteRepository,
+    StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
     StoredProxyNodeMetricsBucket, TunnelMetricsSample, PROXY_NODE_EVENT_TYPE_TUNNEL_ERROR,
 };
 use crate::DataLayerError;
@@ -590,6 +591,10 @@ impl ProxyNodeWriteRepository for InMemoryProxyNodeRepository {
                 mutation.proxy_metadata.as_ref(),
                 mutation.proxy_version.as_deref(),
             );
+            let normalized_proxy_metadata = preserve_proxy_metadata_tunnel_security(
+                previous_proxy_metadata.as_ref(),
+                normalized_proxy_metadata,
+            );
             if let Some(value) = normalized_proxy_metadata {
                 node.proxy_metadata = Some(value);
             }

crates/aether-data/src/repository/proxy_nodes/mysql.rs

@@ -4,11 +4,12 @@ use sqlx::{mysql::MySqlRow, Row};
 use super::types::{
     bucket_start_unix_secs, build_tunnel_error_event_detail, build_tunnel_metrics_sample,
     log_reported_tunnel_error_event, normalize_proxy_metadata,
-    reconcile_remote_config_after_heartbeat, ProxyNodeEventQuery, ProxyNodeHeartbeatMutation,
+    preserve_proxy_metadata_tunnel_security, reconcile_remote_config_after_heartbeat,
-    ProxyNodeManualCreateMutation, ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary,
+    ProxyNodeEventQuery, ProxyNodeHeartbeatMutation, ProxyNodeManualCreateMutation,
-    ProxyNodeMetricsStep, ProxyNodeReadRepository, ProxyNodeRegistrationMutation,
+    ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary, ProxyNodeMetricsStep,
-    ProxyNodeRemoteConfigMutation, ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation,
+    ProxyNodeReadRepository, ProxyNodeRegistrationMutation, ProxyNodeRemoteConfigMutation,
-    ProxyNodeWriteRepository, StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
+    ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation, ProxyNodeWriteRepository,
+    StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
     StoredProxyNodeMetricsBucket, PROXY_NODE_EVENT_TYPE_TUNNEL_ERROR,
 };
 use crate::driver::mysql::MysqlPool;
@@ -779,10 +780,15 @@ WHERE is_manual = 0
         if let Some(value) = mutation.avg_latency_ms {
             node.avg_latency_ms = Some(value);
         }
-        if let Some(value) = normalize_proxy_metadata(
+        let normalized_proxy_metadata = normalize_proxy_metadata(
             mutation.proxy_metadata.as_ref(),
             mutation.proxy_version.as_deref(),
-        ) {
+        );
+        let normalized_proxy_metadata = preserve_proxy_metadata_tunnel_security(
+            previous_proxy_metadata.as_ref(),
+            normalized_proxy_metadata,
+        );
+        if let Some(value) = normalized_proxy_metadata {
             node.proxy_metadata = Some(value);
         }
         if let Some(value) = mutation.total_requests_delta.filter(|value| *value > 0) {

crates/aether-data/src/repository/proxy_nodes/postgres.rs

@@ -6,11 +6,12 @@ use sqlx::{postgres::PgRow, PgPool, Postgres, QueryBuilder, Row};
 use super::types::{
     bucket_start_unix_secs, build_tunnel_error_event_detail, build_tunnel_metrics_sample,
     log_reported_tunnel_error_event, normalize_proxy_metadata,
-    reconcile_remote_config_after_heartbeat, ProxyNodeEventQuery, ProxyNodeHeartbeatMutation,
+    preserve_proxy_metadata_tunnel_security, reconcile_remote_config_after_heartbeat,
-    ProxyNodeManualCreateMutation, ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary,
+    ProxyNodeEventQuery, ProxyNodeHeartbeatMutation, ProxyNodeManualCreateMutation,
-    ProxyNodeMetricsStep, ProxyNodeReadRepository, ProxyNodeRegistrationMutation,
+    ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary, ProxyNodeMetricsStep,
-    ProxyNodeRemoteConfigMutation, ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation,
+    ProxyNodeReadRepository, ProxyNodeRegistrationMutation, ProxyNodeRemoteConfigMutation,
-    ProxyNodeWriteRepository, StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
+    ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation, ProxyNodeWriteRepository,
+    StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
     StoredProxyNodeMetricsBucket, TunnelMetricsSample, PROXY_NODE_EVENT_TYPE_TUNNEL_ERROR,
 };
 use crate::{
@@ -1174,6 +1175,10 @@ impl ProxyNodeWriteRepository for SqlxProxyNodeRepository {
             mutation.proxy_metadata.as_ref(),
             mutation.proxy_version.as_deref(),
         );
+        let normalized_proxy_metadata = preserve_proxy_metadata_tunnel_security(
+            existing.proxy_metadata.as_ref(),
+            normalized_proxy_metadata,
+        );
 
         sqlx::query(APPLY_HEARTBEAT_SQL)
             .bind(&mutation.node_id)

crates/aether-data/src/repository/proxy_nodes/sqlite.rs

@@ -4,11 +4,12 @@ use sqlx::{sqlite::SqliteRow, QueryBuilder, Row, Sqlite};
 use super::types::{
     bucket_start_unix_secs, build_tunnel_error_event_detail, build_tunnel_metrics_sample,
     log_reported_tunnel_error_event, normalize_proxy_metadata,
-    reconcile_remote_config_after_heartbeat, ProxyNodeEventQuery, ProxyNodeHeartbeatMutation,
+    preserve_proxy_metadata_tunnel_security, reconcile_remote_config_after_heartbeat,
-    ProxyNodeManualCreateMutation, ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary,
+    ProxyNodeEventQuery, ProxyNodeHeartbeatMutation, ProxyNodeManualCreateMutation,
-    ProxyNodeMetricsStep, ProxyNodeReadRepository, ProxyNodeRegistrationMutation,
+    ProxyNodeManualUpdateMutation, ProxyNodeMetricsCleanupSummary, ProxyNodeMetricsStep,
-    ProxyNodeRemoteConfigMutation, ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation,
+    ProxyNodeReadRepository, ProxyNodeRegistrationMutation, ProxyNodeRemoteConfigMutation,
-    ProxyNodeWriteRepository, StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
+    ProxyNodeTrafficMutation, ProxyNodeTunnelStatusMutation, ProxyNodeWriteRepository,
+    StoredProxyFleetMetricsBucket, StoredProxyNode, StoredProxyNodeEvent,
     StoredProxyNodeMetricsBucket, PROXY_NODE_EVENT_TYPE_TUNNEL_ERROR,
 };
 use crate::driver::sqlite::SqlitePool;
@@ -770,10 +771,15 @@ WHERE is_manual = 0
         if let Some(value) = mutation.avg_latency_ms {
             node.avg_latency_ms = Some(value);
         }
-        if let Some(value) = normalize_proxy_metadata(
+        let normalized_proxy_metadata = normalize_proxy_metadata(
             mutation.proxy_metadata.as_ref(),
             mutation.proxy_version.as_deref(),
-        ) {
+        );
+        let normalized_proxy_metadata = preserve_proxy_metadata_tunnel_security(
+            previous_proxy_metadata.as_ref(),
+            normalized_proxy_metadata,
+        );
+        if let Some(value) = normalized_proxy_metadata {
             node.proxy_metadata = Some(value);
         }
         if let Some(value) = mutation.total_requests_delta.filter(|value| *value > 0) {

crates/aether-data/src/repository/proxy_nodes/types.rs

@@ -485,6 +485,34 @@ pub fn normalize_proxy_metadata(
     }
 }
 
+pub fn preserve_proxy_metadata_tunnel_security(
+    previous_proxy_metadata: Option<&Value>,
+    next_proxy_metadata: Option<Value>,
+) -> Option<Value> {
+    let Some(tunnel_security) = previous_proxy_metadata
+        .and_then(|value| value.get("tunnel_security"))
+        .filter(|value| value.is_object())
+        .cloned()
+    else {
+        return next_proxy_metadata;
+    };
+
+    match next_proxy_metadata {
+        Some(Value::Object(mut metadata)) => {
+            metadata
+                .entry("tunnel_security".to_string())
+                .or_insert(tunnel_security);
+            Some(Value::Object(metadata))
+        }
+        Some(value) => Some(value),
+        None => {
+            let mut metadata = serde_json::Map::new();
+            metadata.insert("tunnel_security".to_string(), tunnel_security);
+            Some(Value::Object(metadata))
+        }
+    }
+}
+
 fn extract_tunnel_metrics_counters(
     proxy_metadata: Option<&Value>,
 ) -> Option<TunnelMetricsCounters> {
@@ -772,10 +800,10 @@ mod tests {
 
     use super::{
         bucket_start_unix_secs, build_tunnel_error_event_detail, build_tunnel_metrics_sample,
-        normalize_proxy_node_scheduling_state, proxy_node_accepts_new_tunnels,
+        normalize_proxy_node_scheduling_state, preserve_proxy_metadata_tunnel_security,
-        proxy_reported_version, reconcile_remote_config_after_heartbeat,
+        proxy_node_accepts_new_tunnels, proxy_reported_version,
-        remote_config_scheduling_state, remote_config_upgrade_target, ProxyNodeMetricsStep,
+        reconcile_remote_config_after_heartbeat, remote_config_scheduling_state,
-        StoredProxyNode,
+        remote_config_upgrade_target, ProxyNodeMetricsStep, StoredProxyNode,
     };
 
     #[test]
@@ -934,6 +962,40 @@ mod tests {
         );
     }
 
+    #[test]
+    fn preserves_secure_tunnel_metadata_across_heartbeat_metadata_refresh() {
+        let previous = json!({
+            "version": "1.0.0",
+            "tunnel_security": {
+                "mode": "non_tls_required",
+                "encryption_key": "BwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwc="
+            }
+        });
+        let next = json!({
+            "version": "1.0.1",
+            "tunnel_metrics": {"connect_successes": 1}
+        });
+
+        let merged = preserve_proxy_metadata_tunnel_security(Some(&previous), Some(next))
+            .expect("metadata should remain present");
+        assert_eq!(
+            merged
+                .pointer("/tunnel_security/mode")
+                .and_then(|v| v.as_str()),
+            Some("non_tls_required")
+        );
+        assert_eq!(
+            merged
+                .pointer("/tunnel_security/encryption_key")
+                .and_then(|v| v.as_str()),
+            Some("BwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwc=")
+        );
+        assert_eq!(
+            merged.pointer("/tunnel_metrics/connect_successes"),
+            Some(&json!(1))
+        );
+    }
+
     #[test]
     fn maps_timestamps_to_metric_buckets() {
         assert_eq!(

crates/aether-testkit/src/bin/capacity_curve_baseline.rs

@@ -609,6 +609,9 @@ fn relay_envelope() -> Vec<u8> {
             "content-type".to_string(),
             "application/json".to_string(),
         )]),
+        stream: false,
+        request_timeout_ms: None,
+        stream_first_byte_timeout_ms: None,
         timeout: 30,
         follow_redirects: None,
         http1_only: false,

crates/aether-testkit/src/bin/gateway_tunnel_stream_baseline.rs

@@ -117,6 +117,9 @@ fn relay_envelope() -> Vec<u8> {
             "content-type".to_string(),
             "application/json".to_string(),
         )]),
+        stream: true,
+        request_timeout_ms: None,
+        stream_first_byte_timeout_ms: None,
         timeout: 30,
         follow_redirects: None,
         http1_only: false,

crates/aether-testkit/src/bin/multi_instance_owner_relay_baseline.rs

@@ -253,6 +253,9 @@ fn relay_envelope() -> Vec<u8> {
             "content-type".to_string(),
             "application/json".to_string(),
         )]),
+        stream: false,
+        request_timeout_ms: None,
+        stream_first_byte_timeout_ms: None,
         timeout: 30,
         follow_redirects: None,
         http1_only: false,