Fix date handling for SDK v1.0

SDK v1.0 returns message.date as ISO string, not Date object.
Handle both formats for compatibility.

🐾 Generated with [Letta Code](https://letta.com)

Co-Authored-By: Letta <[e-mail]>

.letta/settings.json

···
+{
+  "localSharedBlockIds": {
+    "project": "block-51ffd472-f447-41a4-8822-af0e7863fa88"
+  },
+  "permissions": {
+    "allow": [
+      "Bash(ls:*)",
+      "Bash(magick /Users/cameron/letta/co/assets/co-logo-dark.png -resize 1024x1024 -background none -gravity center -extent 1024x1024 /Users/cameron/letta/co/assets/adaptive-icon.png)",
+      "Edit(src/screens/**)",
+      "Edit(/**)",
+      "Bash(git branch:*)",
+      "Bash(find:*)",
+      "Bash(npx vercel dist --prod --yes)",
+      "Bash(cd /Users/cameron/letta/co && git log:*)",
+      "Bash(cd /Users/cameron/letta/co && git status:*)",
+      "Bash(cd /Users/cameron/letta/co && git show:*)",
+      "Bash(cd /Users/cameron/letta/co && git add:*)"
+    ]
+  }
+}

.letta/settings.local.json

···
+{
+  "lastAgent": "agent-83404fe5-3b77-4ea0-8333-75c6d50d751e"
+}

polyfills.ts

···
+/**
+ * Polyfills for React Native
+ *
+ * React Native doesn't have native support for:
+ * - TextEncoder/TextDecoder - needed by some libraries
+ * - Base64 encoding - needed for file uploads
+ * - URL parsing - needed for API calls
+ *
+ * This file loads polyfills to add these missing APIs.
+ */
+
+import { Platform } from 'react-native';
+
+// Only apply polyfills on native platforms
+if (Platform.OS !== 'web') {
+  console.log('🔧 Loading polyfills for React Native...');
+  
+  // Load basic polyfills (encoding, base64, URL)
+  require('react-native-polyfill-globals/src/encoding');
+  require('react-native-polyfill-globals/src/base64');
+  require('react-native-polyfill-globals/src/url');
+  
+  console.log('✅ Basic polyfills loaded (encoding, base64, URL)');
+} else {
+  console.log('🌐 Running on web, no polyfills needed');
+}

src/api/lettaApi.ts

···
           id: message.id,
           role,
           content,
-          created_at: message.date ? message.date.toISOString() : new Date().toISOString(),
+          created_at: message.date ? (typeof message.date === 'string' ? message.date : message.date.toISOString()) : new Date().toISOString(),
           tool_calls: message.tool_calls,
           message_type: type,
           sender_id: message.senderId,
···
           id: message.id,
           role,
           content,
-          created_at: message.date ? message.date.toISOString() : new Date().toISOString(),
+          created_at: message.date ? (typeof message.date === 'string' ? message.date : message.date.toISOString()) : new Date().toISOString(),
           tool_calls: message.tool_calls,
           message_type: type,
           sender_id: message.senderId,
···
             id: message.id,
             role,
             content,
-            created_at: message.date ? message.date.toISOString() : new Date().toISOString(),
+            created_at: message.date ? (typeof message.date === 'string' ? message.date : message.date.toISOString()) : new Date().toISOString(),
             tool_calls: message.tool_calls,
             message_type: type,
             sender_id: message.senderId,
···
               id: message.id,
               role,
               content,
-              created_at: message.date ? new Date(message.date).toISOString() : new Date().toISOString(),
+              created_at: message.date ? (typeof message.date === 'string' ? message.date : message.date.toISOString()) : new Date().toISOString(),
               tool_calls: message.tool_calls,
               message_type: type,
               sender_id: message.senderId,

test-image.py

···
+import base64
+import httpx
+import os
+from letta_client import Letta
+
+token = os.getenv('LETTA_API_KEY')
+if not token:
+    print("Error: LETTA_API_KEY environment variable not set")
+    exit(1)
+
+client = Letta(token=token)
+
+image_url = "https://upload.wikimedia.org/wikipedia/commons/a/a7/Camponotus_flavomarginatus_ant.jpg"
+image_data = base64.standard_b64encode(httpx.get(image_url).content).decode("utf-8")
+
+response = client.agents.messages.create(
+    agent_id="agent-bb780791-961a-4fa3-95ba-b681b6d508e6",
+    messages=[
+        {
+            "role": "user",
+            "content": [
+                {
+                    "type": "image",
+                    "source": {
+                        "type": "base64",
+                        "media_type": "image/jpeg",
+                        "data": image_data,
+                    },
+                },
+                {
+                    "type": "text",
+                    "text": "Describe this image."
+                }
+            ],
+        }
+    ],
+)
+
+print("Response:")
+print(response)

test-image.ts

···
+import { LettaClient } from '@letta-ai/letta-client';
+
+async function testImage() {
+    const token = process.env.LETTA_API_KEY;
+    if (!token) {
+        console.error('Error: LETTA_API_KEY environment variable not set');
+        process.exit(1);
+    }
+
+    const client = new LettaClient({ token });
+
+    const imageUrl = "https://upload.wikimedia.org/wikipedia/commons/a/a7/Camponotus_flavomarginatus_ant.jpg";
+    const imageResponse = await fetch(imageUrl);
+    const imageBuffer = await imageResponse.arrayBuffer();
+    const imageData = Buffer.from(imageBuffer).toString('base64');
+
+    const response = await client.agents.messages.create(
+        "agent-bb780791-961a-4fa3-95ba-b681b6d508e6", {
+            messages: [
+                {
+                    role: "user",
+                    content: [
+                        {
+                            type: "text",
+                            text: "Describe this image."
+                        },
+                        {
+                            type: "image",
+                            source: {
+                                type: "base64",
+                                mediaType: "image/jpeg",
+                                data: imageData,
+                            },
+                        }
+                    ],
+                }
+            ],
+        }
+    );
+
+    console.log('Response:', response);
+}
+
+testImage().catch(console.error);