# Routes

> Traffic routing rules and backend configuration

Routes define how traffic flows to backend services through Kubernetes Gateway API resources. HTTP and gRPC routes attach to [domains](./domains.md) and match on hostname, path, and headers. TCP and UDP routes attach to [streams](./streams.md) and route by listener port.

![A domain's Routes tab in FastGateway, showing a prefix route forwarding to a backend service](/img/ui-routes.jpg)

## Route Types

| Type | Resource | Attaches to | Use Case |
|------|----------|-------------|----------|
| HTTP | HTTPRoute | Domain | REST APIs, web applications |
| gRPC | GRPCRoute | Domain | gRPC services |
| TCP | TCPRoute | Stream | Databases, Redis, Kafka, other TCP services |
| UDP | UDPRoute | Stream | DNS, syslog, other UDP services |

HTTP and gRPC routes are hostname-keyed: they match incoming requests by hostname, path, header, method, and query. TCP and UDP routes are port-keyed: they route by the listener port alone, with no Layer-7 matching. See [Streams](./streams.md) for how TCP and UDP routing works.

## Matching Rules

Routes match incoming requests using:

| Match Type | HTTP | gRPC |
|------------|------|------|
| Path | `/api/v1/*` | N/A |
| Method | `GET`, `POST` | N/A |
| Headers | `X-Version: v2` | `X-Version: v2` |
| Query Parameters | `?debug=true` | N/A |
| Service/Method | N/A | `myservice/MyMethod` |

## Backend Configuration

On the route builder's Traffic tab, a route forwards to one or more backends. Each backend is a Kubernetes Service (namespace, service, port) or an external service (address, port). Add more than one backend to split traffic by weight, or mark a backend as a fallback so it only takes traffic when the primaries are unhealthy.

| Field | Description |
|-------|-------------|
| Backend type | Kubernetes Service, or External Service |
| Service / Port | The target service and port (plus namespace for Kubernetes services) |
| Weight | Share of traffic (0 to 100) when splitting across backends |
| Role | Primary, or Fallback for failover |

## Approval Workflow

Routes follow a controlled deployment process:

```mermaid
flowchart LR
    A["Submit"] --> B["Approve"] --> C["Deploy"]

    classDef step fill:#eff6ff,stroke:#2563eb,stroke-width:1.5px,color:#1e293b;
    class A,B,C step;
```

| Status | Description |
|--------|-------------|
| Pending | Awaiting approval |
| Approved | Ready for deployment |
| Deployed | Active in Kubernetes |
| Rejected | Approval denied |

## Traffic Features

Routes support advanced traffic management:

- **Timeouts**: Request and backend timeouts
- **Retries**: Automatic retry with backoff
- **Rate Limiting**: Request throttling
- **Circuit Breaker**: Failure protection