Allow custom code exchange (#12)

Co-authored-by: Aaron de Mello <314152+AaronDDM@users.noreply.github.com>

Author: radenkovic

.changeset/custom-code-exchange.md

@@ -0,0 +1,26 @@
+---
+"@nylas/connect": major
+---
+
+Add custom code exchange functionality for enhanced security.
+
+### Usage
+
+```typescript
+// Handle code exchange on your backend
+const nylasConnect = new NylasConnect({
+  clientId: 'your-client-id',
+  redirectUri: 'http://localhost:3000/callback',
+  codeExchange: async (params) => {
+    const response = await fetch('/api/auth/exchange', {
+      method: 'POST',
+      body: JSON.stringify(params),
+    });
+    return await response.json();
+  }
+});
+
+// Use normally - custom exchange is called automatically
+const result = await nylasConnect.connect({ method: 'popup' });
+```
+

.github/workflows/pr-tests.yml

@@ -16,7 +16,7 @@ concurrency:
 jobs:
   test:
     name: Test Suite
-    runs-on: blacksmith-2vcpu-ubuntu-2404
+    runs-on: ubuntu-latest
     timeout-minutes: 15
 
     steps:

.github/workflows/release.yml

@@ -12,7 +12,7 @@ concurrency: ${{ github.workflow }}-${{ github.ref }}
 jobs:
   release:
     name: Release
-    runs-on: blacksmith-2vcpu-ubuntu-2404
+    runs-on: ubuntu-latest
     permissions:
       contents: write # to create release commits and tags
       pull-requests: write # to create release PRs

packages/nylas-connect/README.md

@@ -119,6 +119,81 @@ try {
 | `apiUrl` | `string` | `https://api.us.nylas.com` | API base URL |
 | `persistTokens` | `boolean` | `true` | Store tokens in localStorage |
 | `debug` | `boolean` | `true` on localhost | Enable debug logging |
+| `codeExchange` | (param: CodeExchangeParams) => Promise<ConnectResult>` | - | Custom code exchange method |
+
+## Custom Code Exchange
+
+For enhanced security, you can handle the OAuth code exchange on your backend instead of in the browser. This approach keeps your API keys secure and gives you full control over the token exchange process.
+
+### Backend Code Exchange
+
+```typescript
+const nylasConnect = new NylasConnect({
+  clientId: 'your-nylas-client-id',
+  redirectUri: 'http://localhost:3000/auth/callback',
+  codeExchange: async (params) => {
+    // Send the authorization code to your backend
+    const response = await fetch('/api/auth/exchange', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        code: params.code,
+        state: params.state,
+        clientId: params.clientId,
+        redirectUri: params.redirectUri,
+        scopes: params.scopes,
+        provider: params.provider,
+      }),
+    });
+
+    if (!response.ok) {
+      throw new Error(`Token exchange failed: ${response.statusText}`);
+    }
+
+    const tokenData = await response.json();
+    
+    // Return the expected ConnectResult format
+    return {
+      accessToken: tokenData.access_token,
+      idToken: tokenData.id_token,
+      grantId: tokenData.grant_id,
+      expiresAt: Date.now() + tokenData.expires_in * 1000,
+      scope: tokenData.scope,
+      grantInfo: tokenData.grant_info,
+    };
+  }
+});
+
+// Use normally - the custom exchange will be called automatically
+const result = await nylasConnect.connect({ method: 'popup' });
+```
+
+### Backend Implementation Example
+
+```typescript
+// Example backend endpoint (/api/auth/exchange)
+export async function POST(request: Request) {
+  const { code, clientId, redirectUri } = await request.json();
+  
+  // Exchange code for tokens using your API key
+  const response = await fetch('https://api.us.nylas.com/connect/token', {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/x-www-form-urlencoded',
+      'Authorization': `Bearer ${process.env.NYLAS_API_KEY}`,
+    },
+    body: new URLSearchParams({
+      client_id: clientId,
+      redirect_uri: redirectUri,
+      code,
+      grant_type: 'authorization_code',
+    }),
+  });
+
+  const tokenData = await response.json();
+  return Response.json(tokenData);
+}
+```
 
 ## API