diff --git a/.github/workflows/backend-ci.yml b/.github/workflows/backend-ci.yml
index 6c4a028c9..ece09c5dc 100644
--- a/.github/workflows/backend-ci.yml
+++ b/.github/workflows/backend-ci.yml
@@ -17,6 +17,7 @@ jobs:
           /bin/bash -n deploy/apple-container.sh
           /bin/bash deploy/tests/apple-container-test.sh
           /bin/sh deploy/tests/docker-compose-security-test.sh
+          /bin/sh deploy/tests/docker-compose-gateway-env-test.sh
           /bin/sh deploy/tests/docker-runtime-resources-test.sh
           /bin/sh deploy/test-caddyfile-cache.sh
 
diff --git a/README.md b/README.md
index 127653ce8..50ffe7e43 100644
--- a/README.md
+++ b/README.md
@@ -640,6 +640,32 @@ Or set `GATEWAY_OPENAI_WS_MODE_ROUTER_V2_ENABLED=true` in the environment.
 Use `http_bridge` for client-WebSocket/upstream-HTTP operation when rolling out
 or mitigating upstream WebSocket issues.
 
+#### Force OpenAI upstream HTTP/SSE
+
+When an egress proxy or network repeatedly reconnects OpenAI Responses
+WebSockets, set the global fallback in the persisted deployment configuration:
+
+```yaml
+gateway:
+  openai_ws:
+    force_http: true
+```
+
+For Compose and Apple container deployments, the equivalent `.env` setting is:
+
+```bash
+GATEWAY_OPENAI_WS_FORCE_HTTP=true
+```
+
+This selects HTTP/SSE for OpenAI upstream Responses traffic that would
+otherwise use WebSocket. It does not change the client-facing protocol or force
+HTTP/1.1; configure `gateway.openai_http2.enabled` (or
+`GATEWAY_OPENAI_HTTP2_ENABLED=false`) separately when a proxy is incompatible
+with HTTP/2. Unlike the account-level `http_bridge` mode, this global fallback
+takes effect without enabling `mode_router_v2_enabled`. Keep the setting in the
+deployment's persisted `.env` or `config.yaml`, rather than inside a running
+container, so it is read again after an image update or container recreation.
+
 #### ⚠️ Important: Creating the Admin Account
 
 The initial admin account is **only created via the setup wizard** (served at `http://<host>:8080` on first run). The `default.admin_email` / `default.admin_password` fields in `config.yaml` are **not used** to create it — they exist in the template for historical reasons.
diff --git a/backend/internal/config/config_test.go b/backend/internal/config/config_test.go
index d8cfe820b..7cef4dfc1 100644
--- a/backend/internal/config/config_test.go
+++ b/backend/internal/config/config_test.go
@@ -553,6 +553,15 @@ func TestLoadOpenAIWSClientFirstMessageTimeoutFromEnv(t *testing.T) {
 	require.Equal(t, 120, cfg.Gateway.OpenAIWS.ClientFirstMessageTimeoutSeconds)
 }
 
+func TestLoadOpenAIWSForceHTTPFromEnv(t *testing.T) {
+	resetViperWithJWTSecret(t)
+	t.Setenv("GATEWAY_OPENAI_WS_FORCE_HTTP", "true")
+
+	cfg, err := Load()
+	require.NoError(t, err)
+	require.True(t, cfg.Gateway.OpenAIWS.ForceHTTP)
+}
+
 func TestLoadDefaultOpenAICompactModel(t *testing.T) {
 	resetViperWithJWTSecret(t)
 
diff --git a/backend/internal/service/openai_ws_protocol_resolver_test.go b/backend/internal/service/openai_ws_protocol_resolver_test.go
index 12e047f10..32716a2c7 100644
--- a/backend/internal/service/openai_ws_protocol_resolver_test.go
+++ b/backend/internal/service/openai_ws_protocol_resolver_test.go
@@ -87,6 +87,15 @@ func TestOpenAIWSProtocolResolver_Resolve(t *testing.T) {
 		require.Equal(t, "account_force_http", decision.Reason)
 	})
 
+	t.Run("全局强制HTTP无需启用mode router", func(t *testing.T) {
+		cfg := *baseCfg
+		cfg.Gateway.OpenAIWS.ForceHTTP = true
+
+		decision := NewOpenAIWSProtocolResolver(&cfg).Resolve(openAIOAuthEnabled)
+		require.Equal(t, OpenAIUpstreamTransportHTTPSSE, decision.Transport)
+		require.Equal(t, "global_force_http", decision.Reason)
+	})
+
 	t.Run("全局关闭保持HTTP", func(t *testing.T) {
 		cfg := *baseCfg
 		cfg.Gateway.OpenAIWS.Enabled = false
diff --git a/deploy/.env.example b/deploy/.env.example
index 6beca8830..76762e303 100644
--- a/deploy/.env.example
+++ b/deploy/.env.example
@@ -285,6 +285,11 @@ GATEWAY_FORCE_CODEX_CLI=false
 GATEWAY_OPENAI_COMPACT_MODEL=gpt-5.4
 # OpenAI/Codex 等待上游响应头超时（秒）；0 表示不使用本地响应头超时截断。
 GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT=0
+# 全局强制 OpenAI Responses 上游使用 HTTP/SSE，不使用 WebSocket。
+# 当代理或网络导致上游 WebSocket 反复重连时可设为 true；这不会禁用 HTTP/2。
+# 如需回退 HTTP/1.1，请另行设置 GATEWAY_OPENAI_HTTP2_ENABLED=false。
+# 将此项保存在持久化 .env 中，镜像更新或容器重建后会在启动时重新读取。
+GATEWAY_OPENAI_WS_FORCE_HTTP=false
 # OpenAI HTTP 上游默认启用 HTTP/2；如需紧急回滚可设为 false。
 GATEWAY_OPENAI_HTTP2_ENABLED=true
 GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1=true
diff --git a/deploy/config.example.yaml b/deploy/config.example.yaml
index 1e4de333e..a0dbfbf97 100644
--- a/deploy/config.example.yaml
+++ b/deploy/config.example.yaml
@@ -329,7 +329,8 @@ gateway:
     # 按账号类型细分开关
     oauth_enabled: true
     apikey_enabled: true
-    # 全局强制 HTTP（紧急回滚开关）
+    # 全局强制 OpenAI Responses 上游使用 HTTP/SSE，不使用 WebSocket（紧急回滚开关）。
+    # 此开关不强制 HTTP/1.1；HTTP/2 由 gateway.openai_http2 单独控制。
     force_http: false
     # 允许在 WSv2 下按策略恢复 store=true（默认 false）
     allow_store_recovery: false
diff --git a/deploy/docker-compose.dev.yml b/deploy/docker-compose.dev.yml
index 8603f121d..392801e0a 100644
--- a/deploy/docker-compose.dev.yml
+++ b/deploy/docker-compose.dev.yml
@@ -53,8 +53,12 @@ services:
       - HTTPS_PROXY=${SUB2API_DEV_HTTPS_PROXY:-http://host.docker.internal:7897}
       - ALL_PROXY=${SUB2API_DEV_ALL_PROXY:-socks5://host.docker.internal:7897}
       - NO_PROXY=${SUB2API_DEV_NO_PROXY:-127.0.0.1,localhost,::1,postgres,redis,sub2api,192.168.0.0/16,10.0.0.0/8,172.16.0.0/12,.local}
-      # OpenAI HTTP upstream protocol/timeout
+      # Gateway values come from Compose .env or the shell.
+      # Fallbacks mirror Sub2API backend defaults so omitted values preserve behavior.
+      - GATEWAY_FORCE_CODEX_CLI=${GATEWAY_FORCE_CODEX_CLI:-false}
+      - GATEWAY_OPENAI_COMPACT_MODEL=${GATEWAY_OPENAI_COMPACT_MODEL:-gpt-5.4}
       - GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT=${GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT:-0}
+      - GATEWAY_OPENAI_WS_FORCE_HTTP=${GATEWAY_OPENAI_WS_FORCE_HTTP:-false}
       - GATEWAY_OPENAI_HTTP2_ENABLED=${GATEWAY_OPENAI_HTTP2_ENABLED:-true}
       - GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1=${GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1:-true}
       - GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD=${GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD:-2}
@@ -63,8 +67,28 @@ services:
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD:-2}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS:-60}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS:-600}
+      - GATEWAY_MAX_BODY_SIZE=${GATEWAY_MAX_BODY_SIZE:-268435456}
+      - GATEWAY_MAX_CONNS_PER_HOST=${GATEWAY_MAX_CONNS_PER_HOST:-1024}
+      - GATEWAY_MAX_IDLE_CONNS=${GATEWAY_MAX_IDLE_CONNS:-2560}
+      - GATEWAY_MAX_IDLE_CONNS_PER_HOST=${GATEWAY_MAX_IDLE_CONNS_PER_HOST:-120}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING=${GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING:-3}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT:-120s}
+      - GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT:-30s}
+      - GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING=${GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING:-100}
+      - GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED=${GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED:-true}
+      - GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL=${GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL:-30s}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED=${GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED:-true}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS=${GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS:-0}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS=${GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS:-0}
+      - GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS:-1}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS:-5}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS:-10}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES:-3}
+      - GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS=${GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS:-10000}
+      - GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS:-300}
       - GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT=${GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT:-900}
       - GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL:-10}
+      - GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL:-0}
       - GATEWAY_IMAGE_CONCURRENCY_ENABLED=${GATEWAY_IMAGE_CONCURRENCY_ENABLED:-false}
       - GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS=${GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS:-0}
       - GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE=${GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE:-reject}
diff --git a/deploy/docker-compose.local.yml b/deploy/docker-compose.local.yml
index 588862e2f..0df1fb0d8 100644
--- a/deploy/docker-compose.local.yml
+++ b/deploy/docker-compose.local.yml
@@ -159,10 +159,14 @@ services:
       - UPDATE_PROXY_URL=${UPDATE_PROXY_URL:-}
 
       # =======================================================================
-      # Image Generation Stream & Concurrency
+      # Gateway Upstream, Scheduling & Image Configuration
       # =======================================================================
-      # OpenAI HTTP upstream protocol/timeout
+      # Gateway values come from Compose .env or the shell.
+      # Fallbacks mirror Sub2API backend defaults so omitted values preserve behavior.
+      - GATEWAY_FORCE_CODEX_CLI=${GATEWAY_FORCE_CODEX_CLI:-false}
+      - GATEWAY_OPENAI_COMPACT_MODEL=${GATEWAY_OPENAI_COMPACT_MODEL:-gpt-5.4}
       - GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT=${GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT:-0}
+      - GATEWAY_OPENAI_WS_FORCE_HTTP=${GATEWAY_OPENAI_WS_FORCE_HTTP:-false}
       - GATEWAY_OPENAI_HTTP2_ENABLED=${GATEWAY_OPENAI_HTTP2_ENABLED:-true}
       - GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1=${GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1:-true}
       - GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD=${GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD:-2}
@@ -171,8 +175,28 @@ services:
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD:-2}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS:-60}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS:-600}
+      - GATEWAY_MAX_BODY_SIZE=${GATEWAY_MAX_BODY_SIZE:-268435456}
+      - GATEWAY_MAX_CONNS_PER_HOST=${GATEWAY_MAX_CONNS_PER_HOST:-1024}
+      - GATEWAY_MAX_IDLE_CONNS=${GATEWAY_MAX_IDLE_CONNS:-2560}
+      - GATEWAY_MAX_IDLE_CONNS_PER_HOST=${GATEWAY_MAX_IDLE_CONNS_PER_HOST:-120}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING=${GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING:-3}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT:-120s}
+      - GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT:-30s}
+      - GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING=${GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING:-100}
+      - GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED=${GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED:-true}
+      - GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL=${GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL:-30s}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED=${GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED:-true}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS=${GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS:-0}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS=${GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS:-0}
+      - GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS:-1}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS:-5}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS:-10}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES:-3}
+      - GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS=${GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS:-10000}
+      - GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS:-300}
       - GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT=${GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT:-900}
       - GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL:-10}
+      - GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL:-0}
       - GATEWAY_IMAGE_CONCURRENCY_ENABLED=${GATEWAY_IMAGE_CONCURRENCY_ENABLED:-false}
       - GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS=${GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS:-0}
       - GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE=${GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE:-reject}
diff --git a/deploy/docker-compose.standalone.yml b/deploy/docker-compose.standalone.yml
index cd0a00887..bca5e4851 100644
--- a/deploy/docker-compose.standalone.yml
+++ b/deploy/docker-compose.standalone.yml
@@ -106,10 +106,14 @@ services:
       - ANTIGRAVITY_USER_AGENT_VERSION=${ANTIGRAVITY_USER_AGENT_VERSION:-}
 
       # =======================================================================
-      # Image Generation Stream & Concurrency
+      # Gateway Upstream, Scheduling & Image Configuration
       # =======================================================================
-      # OpenAI HTTP upstream protocol/timeout
+      # Gateway values come from Compose .env or the shell.
+      # Fallbacks mirror Sub2API backend defaults so omitted values preserve behavior.
+      - GATEWAY_FORCE_CODEX_CLI=${GATEWAY_FORCE_CODEX_CLI:-false}
+      - GATEWAY_OPENAI_COMPACT_MODEL=${GATEWAY_OPENAI_COMPACT_MODEL:-gpt-5.4}
       - GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT=${GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT:-0}
+      - GATEWAY_OPENAI_WS_FORCE_HTTP=${GATEWAY_OPENAI_WS_FORCE_HTTP:-false}
       - GATEWAY_OPENAI_HTTP2_ENABLED=${GATEWAY_OPENAI_HTTP2_ENABLED:-true}
       - GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1=${GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1:-true}
       - GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD=${GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD:-2}
@@ -118,8 +122,28 @@ services:
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD:-2}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS:-60}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS:-600}
+      - GATEWAY_MAX_BODY_SIZE=${GATEWAY_MAX_BODY_SIZE:-268435456}
+      - GATEWAY_MAX_CONNS_PER_HOST=${GATEWAY_MAX_CONNS_PER_HOST:-1024}
+      - GATEWAY_MAX_IDLE_CONNS=${GATEWAY_MAX_IDLE_CONNS:-2560}
+      - GATEWAY_MAX_IDLE_CONNS_PER_HOST=${GATEWAY_MAX_IDLE_CONNS_PER_HOST:-120}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING=${GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING:-3}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT:-120s}
+      - GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT:-30s}
+      - GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING=${GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING:-100}
+      - GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED=${GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED:-true}
+      - GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL=${GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL:-30s}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED=${GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED:-true}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS=${GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS:-0}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS=${GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS:-0}
+      - GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS:-1}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS:-5}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS:-10}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES:-3}
+      - GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS=${GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS:-10000}
+      - GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS:-300}
       - GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT=${GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT:-900}
       - GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL:-10}
+      - GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL:-0}
       - GATEWAY_IMAGE_CONCURRENCY_ENABLED=${GATEWAY_IMAGE_CONCURRENCY_ENABLED:-false}
       - GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS=${GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS:-0}
       - GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE=${GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE:-reject}
diff --git a/deploy/docker-compose.yml b/deploy/docker-compose.yml
index 68a51e78d..f15b40590 100644
--- a/deploy/docker-compose.yml
+++ b/deploy/docker-compose.yml
@@ -156,10 +156,14 @@ services:
       - UPDATE_PROXY_URL=${UPDATE_PROXY_URL:-}
 
       # =======================================================================
-      # Image Generation Stream & Concurrency
+      # Gateway Upstream, Scheduling & Image Configuration
       # =======================================================================
-      # OpenAI HTTP upstream protocol/timeout
+      # Gateway values come from Compose .env or the shell.
+      # Fallbacks mirror Sub2API backend defaults so omitted values preserve behavior.
+      - GATEWAY_FORCE_CODEX_CLI=${GATEWAY_FORCE_CODEX_CLI:-false}
+      - GATEWAY_OPENAI_COMPACT_MODEL=${GATEWAY_OPENAI_COMPACT_MODEL:-gpt-5.4}
       - GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT=${GATEWAY_OPENAI_RESPONSE_HEADER_TIMEOUT:-0}
+      - GATEWAY_OPENAI_WS_FORCE_HTTP=${GATEWAY_OPENAI_WS_FORCE_HTTP:-false}
       - GATEWAY_OPENAI_HTTP2_ENABLED=${GATEWAY_OPENAI_HTTP2_ENABLED:-true}
       - GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1=${GATEWAY_OPENAI_HTTP2_ALLOW_PROXY_FALLBACK_TO_HTTP1:-true}
       - GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD=${GATEWAY_OPENAI_HTTP2_FALLBACK_ERROR_THRESHOLD:-2}
@@ -168,8 +172,28 @@ services:
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_FAILURE_THRESHOLD:-2}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_WINDOW_SECONDS:-60}
       - GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS=${GATEWAY_OPENAI_PROXY_STREAM_CIRCUIT_TTL_SECONDS:-600}
+      - GATEWAY_MAX_BODY_SIZE=${GATEWAY_MAX_BODY_SIZE:-268435456}
+      - GATEWAY_MAX_CONNS_PER_HOST=${GATEWAY_MAX_CONNS_PER_HOST:-1024}
+      - GATEWAY_MAX_IDLE_CONNS=${GATEWAY_MAX_IDLE_CONNS:-2560}
+      - GATEWAY_MAX_IDLE_CONNS_PER_HOST=${GATEWAY_MAX_IDLE_CONNS_PER_HOST:-120}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING=${GATEWAY_SCHEDULING_STICKY_SESSION_MAX_WAITING:-3}
+      - GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_STICKY_SESSION_WAIT_TIMEOUT:-120s}
+      - GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT=${GATEWAY_SCHEDULING_FALLBACK_WAIT_TIMEOUT:-30s}
+      - GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING=${GATEWAY_SCHEDULING_FALLBACK_MAX_WAITING:-100}
+      - GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED=${GATEWAY_SCHEDULING_LOAD_BATCH_ENABLED:-true}
+      - GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL=${GATEWAY_SCHEDULING_SLOT_CLEANUP_INTERVAL:-30s}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED=${GATEWAY_SCHEDULING_DB_FALLBACK_ENABLED:-true}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS=${GATEWAY_SCHEDULING_DB_FALLBACK_TIMEOUT_SECONDS:-0}
+      - GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS=${GATEWAY_SCHEDULING_DB_FALLBACK_MAX_QPS:-0}
+      - GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_POLL_INTERVAL_SECONDS:-1}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_WARN_SECONDS:-5}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_SECONDS:-10}
+      - GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES=${GATEWAY_SCHEDULING_OUTBOX_LAG_REBUILD_FAILURES:-3}
+      - GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS=${GATEWAY_SCHEDULING_OUTBOX_BACKLOG_REBUILD_ROWS:-10000}
+      - GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS=${GATEWAY_SCHEDULING_FULL_REBUILD_INTERVAL_SECONDS:-300}
       - GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT=${GATEWAY_IMAGE_STREAM_DATA_INTERVAL_TIMEOUT:-900}
       - GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_STREAM_KEEPALIVE_INTERVAL:-10}
+      - GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL=${GATEWAY_IMAGE_NONSTREAM_KEEPALIVE_INTERVAL:-0}
       - GATEWAY_IMAGE_CONCURRENCY_ENABLED=${GATEWAY_IMAGE_CONCURRENCY_ENABLED:-false}
       - GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS=${GATEWAY_IMAGE_CONCURRENCY_MAX_CONCURRENT_REQUESTS:-0}
       - GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE=${GATEWAY_IMAGE_CONCURRENCY_OVERFLOW_MODE:-reject}
diff --git a/deploy/tests/docker-compose-gateway-env-test.sh b/deploy/tests/docker-compose-gateway-env-test.sh
new file mode 100644
index 000000000..f068410ba
--- /dev/null
+++ b/deploy/tests/docker-compose-gateway-env-test.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+set -eu
+
+repo_root=$(CDPATH= cd -- "$(dirname -- "$0")/../.." && pwd)
+cd "$repo_root"
+
+gateway_variables=$(mktemp "${TMPDIR:-/tmp}/sub2api-gateway-env.XXXXXX")
+cleanup() {
+  rm -f "$gateway_variables"
+}
+trap cleanup EXIT HUP INT TERM
+
+awk '
+  /^GATEWAY_[A-Z0-9_]+=/ {
+    separator = index($0, "=")
+    print substr($0, 1, separator - 1) "\t" substr($0, separator + 1)
+  }
+' deploy/.env.example > "$gateway_variables"
+
+for compose_file in \
+  deploy/docker-compose.yml \
+  deploy/docker-compose.local.yml \
+  deploy/docker-compose.standalone.yml \
+  deploy/docker-compose.dev.yml
+do
+  tab=$(printf '\t')
+  while IFS="$tab" read -r key value; do
+    # .env.example intentionally includes high-capacity tuning examples for
+    # these values. An unconfigured Compose deployment must retain the
+    # backend defaults instead of silently adopting the examples.
+    case "$key" in
+      GATEWAY_MAX_CONNS_PER_HOST) value=1024 ;;
+      GATEWAY_MAX_IDLE_CONNS) value=2560 ;;
+      GATEWAY_MAX_IDLE_CONNS_PER_HOST) value=120 ;;
+    esac
+
+    expected=$(printf '      - %s=${%s:-%s}' "$key" "$key" "$value")
+    expected_count=$(grep -Fxc "$expected" "$compose_file" || true)
+    key_count=$(grep -Ec "^[[:space:]]*-[[:space:]]*${key}([[:space:]]*=.*)?[[:space:]]*$" "$compose_file" || true)
+    if [ "$expected_count" -ne 1 ] || [ "$key_count" -ne 1 ]; then
+      printf '%s must pass %s with the expected fallback exactly once\n' "$compose_file" "$key" >&2
+      exit 1
+    fi
+  done < "$gateway_variables"
+done
+
+printf 'docker compose Gateway environment test passed\n'