📝 docs(architecture): add gateway integrations overview and sidebar entries

Signed-off-by: samzong <[email protected]>

Author: samzong

website/docs/overview/architecture/gateway-integrations.md

@@ -0,0 +1,85 @@
+---
+id: gateway-integrations
+title: Gateway Integrations
+sidebar_label: Gateway Integrations
+description: How the Semantic Router plugs into Envoy AI Gateway, Istio, AIBrix, LLM-D, and the vLLM Production Stack, plus what each integration adds.
+---
+
+The Semantic Router ships with multiple gateway profiles. This page shows **Which gateway plugs in**, **What SR adds**, and **What’s already validated**.
+
+## High-level topology
+
+import ZoomableMermaid from '@site/src/components/ZoomableMermaid';
+
+<ZoomableMermaid title="System Architecture Overview" defaultZoom={5.5}>
+{`
+flowchart LR
+    C[Client / SDK]
+    GW["Gateway<br/>(Envoy | Istio | AIBrix | LLM-D | Prod Stack)"]
+    SR["Semantic Router<br/>(ExtProc gRPC)"]
+    SC["Semantic Cache<br/>(Milvus)"]
+    OBS["Telemetry<br/>(OTel → Prom/Grafana)"]
+    B1["Cloud LLMs<br/>(OpenAI, Anthropic, ...)"]
+    B2["Self-hosted<br/>vLLM workers"]
+
+    C --> GW
+    GW -- ExtProc <br/> Inference Extension --> SR
+    SR -->|headers: model, safety| GW
+    SR --> SC
+    SR --> OBS
+    GW --> B1
+    GW --> B2
+    B1 --> OBS
+    B2 --> OBS
+
+    style SR fill:#1f2937,stroke:#0ea5e9,stroke-width:2,color:#e5e7eb
+    style GW fill:#0f172a,stroke:#a855f7,stroke-width:2,color:#e5e7eb
+`}
+</ZoomableMermaid>
+
+## Supported Profiles
+
+| Gateway profile      | Integration path                           | SR  adds                                                                            | CI status                                                                                                                                                                                                                                                              | Manifests / config                                                                                                       |
+| -------------------- | ------------------------------------------ | ----------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ |
+| **Envoy AI Gateway** | ExtProc gRPC (Envoy AI Gateway → SR)       | Classification → model header, PII/jailbreak, semantic cache, observability headers | [![integration-test-k8s](https://github.com/vllm-project/semantic-router/actions/workflows/integration-test-k8s.yml/badge.svg)](https://github.com/vllm-project/semantic-router/actions/workflows/integration-test-k8s.yml) <br /> [![integration-test-helm](https://github.com/vllm-project/semantic-router/actions/workflows/integration-test-helm.yml/badge.svg)](https://github.com/vllm-project/semantic-router/actions/workflows/integration-test-helm.yml) | [`deploy/kubernetes/ai-gateway`](https://github.com/vllm-project/semantic-router/tree/main/deploy/kubernetes/ai-gateway) |
+| **Istio Gateway**    | Gateway API Inference Extension + ExtProc  | Same as above; demo with dual vLLM backends                                         | Manual guide | [`deploy/kubernetes/istio`](https://github.com/vllm-project/semantic-router/tree/main/deploy/kubernetes/istio)           |
+| **AIBrix Gateway**   | Envoy Gateway API resources + ExtProc      | SR intelligence in front of AIBrix autoscaler and distributed KV                    | Helm + AIBrix manifests; <br /> follows Envoy ExtProc; <br /> Planned E2E                                                                                                                                                                                                                    | [`deploy/kubernetes/aibrix`](https://github.com/vllm-project/semantic-router/tree/main/deploy/kubernetes/aibrix)         |
+| **LLM-D Gateway**    | Istio Gateway + LLM-D schedulers + ExtProc | Semantic routing feeds pool selection in LLM-D                                      | Covered by Istio flow; <br /> Planned E2E                                                                                                                                                                                                                                         | [`deploy/kubernetes/llmd-base`](https://github.com/vllm-project/semantic-router/tree/main/deploy/kubernetes/llmd-base)   |
+
+> **Reading map**: pick your gateway, open the install guide, then jump to the manifests to see the exact resources the diagram refers to.
+
+## Request Flow
+
+<ZoomableMermaid title="System Architecture Overview" defaultZoom={5.5}>
+{`
+sequenceDiagram
+    autonumber
+    participant Client
+    participant Gateway
+    participant SR as Semantic Router
+    participant Cache as Semantic Cache
+    participant Upstream as LLM Backends
+
+    Client->>Gateway: OpenAI-compatible request
+    Gateway->>SR: ExtProc gRPC (headers/body)
+    SR->>SR: PII / jailbreak / category classification
+    SR->>Cache: Semantic lookup
+    alt cache hit
+        SR-->>Gateway: Headers + cached response
+    else miss
+        SR-->>Gateway: Route headers (model, policy flags)
+        Gateway->>Upstream: Forward to chosen backend
+        Upstream-->>Gateway: LLM response
+        Gateway-->>SR: Response headers/body (optional)
+        SR->>Cache: Write entry
+    end
+    Gateway-->>Client: Final response
+`}
+</ZoomableMermaid>
+
+## Where to go next
+
+- **Envoy AI Gateway install**: [installation/k8s/ai-gateway](../../installation/k8s/ai-gateway)
+- **Istio Gateway install**: [installation/k8s/istio](../../installation/k8s/istio)
+- **AIBrix Gateway install**: [installation/k8s/aibrix](../../installation/k8s/aibrix)
+- **LLM-D Gateway install**: [installation/k8s/llm-d](../../installation/k8s/llm-d)

website/sidebars.ts

@@ -27,6 +27,7 @@ const sidebars: SidebarsConfig = {
           label: 'Architecture',
           items: [
             'overview/architecture/system-architecture',
+            'overview/architecture/gateway-integrations',
             'overview/architecture/envoy-extproc',
             'overview/architecture/router-implementation',
           ],