Eme Event Bus Backend Integration

Configure the Eme messaging app to correctly use `VITE_API_BASE` for API calls and SSE (Server-Sent Events) connections, set up Vite development proxy, and update CI/CD health checks.

Scope & Constraints

**DO NOT modify:**

**ONLY modify:**

**Technical requirements:**

Instructions

1. Update Event Bus (src/core/event-bus.js)

**Objective:** Ensure SSE connection and API calls use `VITE_API_BASE` environment variable.

```javascript

const apiBase = import.meta.env.VITE_API_BASE || window.location.origin;

```

**Example pattern:**

```javascript

// Bad

const sseUrl = '/api/events';

// Good

const apiBase = import.meta.env.VITE_API_BASE || window.location.origin;

const sseUrl = `${apiBase}/api/events`;

```

2. Configure Vite Development Proxy (vite.config.js)

**Objective:** Set up proxy for local development when backend runs on different port.

**Example pattern:**

```javascript

export default defineConfig({

server: {

proxy: {

'/api': {

target: 'http://localhost:3001',

changeOrigin: true,

ws: true

}

}

}

});

```

3. Update Environment Variable Template (.env.local.example)

**Objective:** Document the VITE_API_BASE variable for developers.

**Example:**

```bash

Backend API base URL (optional)

Leave empty for development to use proxy

Set for production: https://api.yourapp.com

VITE_API_BASE=

```

4. Update Health Check Script (scripts/test/vercel-health-check.js)

**Objective:** Ensure health check works with configurable API base URL.

**Requirements:**

5. Update CI/CD Workflows (.github/workflows/*)

**Objective:** Ensure workflows use correct Node version and pass environment variables.

For each workflow file:

```yaml

- uses: actions/setup-node@v3

with:

node-version: '20'

```

Testing Checklist

After making changes, verify:

1. **Development mode:**

- [ ] `npm run dev` starts without errors

- [ ] API calls proxy correctly to backend

- [ ] SSE connections establish successfully

2. **Production build:**

- [ ] `VITE_API_BASE` can be set at build time

- [ ] Built app uses correct API base URL

- [ ] SSE connections work with custom API base

3. **Health check:**

- [ ] Script runs successfully with Node 20

- [ ] Accepts environment variable for API base

- [ ] Returns correct exit codes

4. **CI/CD:**

- [ ] Workflows use Node 20

- [ ] All checks pass

- [ ] No UI/CSS files were modified

Example Usage

**Local development:**

```bash

.env.local is empty or has VITE_API_BASE commented out

npm run dev

Uses Vite proxy to backend

```

**Staging deployment:**

```bash

.env.production

VITE_API_BASE=https://api-staging.eme.com

npm run build

```

**Production deployment:**

```bash

VITE_API_BASE=https://api.eme.com npm run build

```

Important Notes