# Encore Frontend

> Connect a frontend application (React, Next.js, Vue, Svelte, etc.) to an Encore.ts backend.

- **Type:** Skill
- **Install:** `agentstack add skill-encoredev-skills-frontend`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [encoredev](https://agentstack.voostack.com/s/encoredev)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** Apache-2.0
- **Upstream author:** [encoredev](https://github.com/encoredev)
- **Source:** https://github.com/encoredev/skills/tree/main/encore/frontend
- **Website:** https://encore.dev

## Install

```sh
agentstack add skill-encoredev-skills-frontend
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Frontend Integration with Encore

## Instructions

Encore provides tools to connect your frontend applications to your backend APIs.

### Generate a TypeScript Client

```bash
# Generate client for local development
encore gen client --output=./frontend/src/client.ts --env=local

# Generate client for a deployed environment
encore gen client --output=./frontend/src/client.ts --env=staging
```

This generates a fully typed client based on your API definitions.

### Using the Generated Client

```typescript
// frontend/src/client.ts is auto-generated
import Client from "./client";

const client = new Client("http://localhost:4000");

// Fully typed API calls
const user = await client.user.getUser({ id: "123" });
console.log(user.email);

const newUser = await client.user.createUser({
  email: "new@example.com",
  name: "New User",
});
```

### React Example

```tsx
// frontend/src/components/UserProfile.tsx
import { useState, useEffect } from "react";
import Client from "../client";

const client = new Client(import.meta.env.VITE_API_URL);

export function UserProfile({ userId }: { userId: string }) {
  const [user, setUser] = useState(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  useEffect(() => {
    client.user.getUser({ id: userId })
      .then(setUser)
      .catch(setError)
      .finally(() => setLoading(false));
  }, [userId]);

  if (loading) return Loading...;
  if (error) return Error: {error.message};
  
  return (
    
      {user.name}
      {user.email}
    
  );
}
```

### React with TanStack Query

```tsx
import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
import Client from "../client";

const client = new Client(import.meta.env.VITE_API_URL);

export function UserProfile({ userId }: { userId: string }) {
  const { data: user, isLoading, error } = useQuery({
    queryKey: ["user", userId],
    queryFn: () => client.user.getUser({ id: userId }),
  });

  if (isLoading) return Loading...;
  if (error) return Error: {error.message};
  
  return {user.name};
}

export function CreateUserForm() {
  const queryClient = useQueryClient();
  
  const mutation = useMutation({
    mutationFn: (data: { email: string; name: string }) => 
      client.user.createUser(data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ["users"] });
    },
  });

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    const formData = new FormData(e.currentTarget);
    mutation.mutate({
      email: formData.get("email") as string,
      name: formData.get("name") as string,
    });
  };

  return (
    
      
      
      
        {mutation.isPending ? "Creating..." : "Create User"}
      
    
  );
}
```

### Next.js Server Components

```tsx
// app/users/[id]/page.tsx
import Client from "@/lib/client";

const client = new Client(process.env.API_URL);

export default async function UserPage({ params }: { params: { id: string } }) {
  const user = await client.user.getUser({ id: params.id });
  
  return (
    
      {user.name}
      {user.email}
    
  );
}
```

### CORS Configuration

Configure CORS in your `encore.app` file:

```json
{
    "id": "my-app",
    "global_cors": {
        "allow_origins_with_credentials": [
            "http://localhost:3000",
            "https://myapp.com",
            "https://*.myapp.com"
        ]
    }
}
```

### CORS Options

| Option | Description |
|--------|-------------|
| `allow_origins_without_credentials` | Origins allowed for non-credentialed requests (default: `["*"]`) |
| `allow_origins_with_credentials` | Origins allowed for credentialed requests (cookies, auth headers) |
| `allow_headers` | Additional request headers to allow |
| `expose_headers` | Additional response headers to expose |
| `debug` | Enable CORS debug logging |

### Authentication from Frontend

For authenticated requests, pass the Authorization header:

```typescript
// Using fetch
const response = await fetch("http://localhost:4000/profile", {
  headers: {
    "Authorization": `Bearer ${token}`,
  },
});

// Or include credentials for cookie-based auth
const response = await fetch("http://localhost:4000/profile", {
  credentials: "include",
});
```

With TanStack Query, configure a default fetcher:

```typescript
const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      queryFn: async ({ queryKey }) => {
        const response = await fetch(queryKey[0] as string, {
          headers: { Authorization: `Bearer ${getToken()}` },
        });
        if (!response.ok) throw new Error("Request failed");
        return response.json();
      },
    },
  },
});
```

### Using Plain Fetch

If you prefer not to use the generated client:

```typescript
async function getUser(id: string) {
  const response = await fetch(`http://localhost:4000/users/${id}`);
  if (!response.ok) {
    throw new Error(`HTTP error: ${response.status}`);
  }
  return response.json();
}

async function createUser(email: string, name: string) {
  const response = await fetch("http://localhost:4000/users", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ email, name }),
  });
  if (!response.ok) {
    throw new Error(`HTTP error: ${response.status}`);
  }
  return response.json();
}
```

### Environment Variables

```bash
# .env.local (Next.js)
NEXT_PUBLIC_API_URL=http://localhost:4000

# .env (Vite)
VITE_API_URL=http://localhost:4000
```

### Guidelines

- Use `encore gen client` to generate typed API clients
- Regenerate the client when your API changes
- Configure CORS in `encore.app` for production domains
- Use `allow_origins_with_credentials` for authenticated requests
- Include `Authorization` header for token-based auth
- Use `credentials: "include"` for cookie-based auth
- Use environment variables for API URLs (different per environment)
- The generated client handles errors and types automatically

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [encoredev](https://github.com/encoredev)
- **Source:** [encoredev/skills](https://github.com/encoredev/skills)
- **License:** Apache-2.0
- **Homepage:** https://encore.dev

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** yes
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** yes
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-encoredev-skills-frontend
- Seller: https://agentstack.voostack.com/s/encoredev
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.