Letta OSS UI — Design skill for Claude Code

What is the Letta OSS UI?

This repo contains an example desktop application for running Letta agents with a visual interface. The code is a fork of [Claude-Cowork](https://github.com/DevAgentForge/Claude-Cowork) that replaces the Claude SDK with the [`@letta-ai/letta-agent-sdk`](https://www.npmjs.com/package/@letta-ai/letta-agent-sdk). It provides a native desktop GUI for interacting with [Letta](https://docs.letta.com/agent-sdk) agents.

https://github.com/user-attachments/assets/570474a1-641b-404d-a1aa-50c080675773

Why Letta Agent SDK?

The [Letta Agent SDK](https://docs.letta.com/agent-sdk) is the SDK interface to [Letta Code](https://github.com/letta-ai/letta-code). Build agents with persistent memory that learn over time.

import { createAgent, resumeSession } from '@letta-ai/letta-agent-sdk';

// First session - agent learns something
const agentId = await createAgent();
const session1 = resumeSession(agentId);
await session1.send('Remember: the secret word is "banana"');
for await (const msg of session1.stream()) { /* ... */ }
session1.close();

// Later... agent still remembers
await using session2 = resumeSession(agentId);
await session2.send('What is the secret word?');
for await (const msg of session2.stream()) {
  if (msg.type === 'assistant') console.log(msg.content); // "banana"
}

**Key concepts:**

• Agent (agentId): Persistent entity with memory that survives across sessions
• Conversation (conversationId): A message thread within an agent
• Session (sessionId): A single execution/connection

Agents remember across conversations (via memory blocks), but each conversation has its own message history. Th