Agent Development Environment (ADE)

The Agent Development Environment (ADE) is Letta’s comprehensive toolkit for creating, testing, and monitoring stateful agents. The ADE provides unprecedented visibility into every aspect of your agent’s operation, including all components of its context window (memory, state, and prompts) as well as tool execution.

Why Use the ADE?

The ADE bridges the gap between development and deployment, providing:

• Complete Transparency: See exactly what your agent “sees,” thinks, and does
• State Control: Directly read and write to your agent’s persistent memory
• Rapid Prototyping: Create and test agents in a fraction of the time required with scripts
• Robust Debugging: Identify and resolve issues by examining your agent’s state in real-time
• Dynamic Management: Add or modify tools, memory blocks, and data sources without recreating your agent
• Seamless Collaboration: Share and iterate on agents by importing and exporting with agent file (.af), which can be used to checkpoint your agent’s state

Core Components of the ADE

The ADE is organized into three main panels, each focusing on different aspects of agent development:

👾 Agent Simulator (Center Panel)

The Agent Simulator is your primary interface for interacting with and testing your agent:

• Chat directly with your agent to test its capabilities
• Send system messages to simulate events and triggers
• Monitor the agent’s responses, tool usage, and reasoning in real-time

⚙️ Agent Configuration (Left Panel)

The Agent Configuration panel allows you to customize every aspect of your agent:

• LLM (Model) Selection: Choose from a variety of language models from providers like OpenAI, Anthropic, and more
• System Instructions: Configure the high-level (read-only) directives that guide your agent’s behavior
• Tools Management: Add, remove, and configure the tools available to your agent
• Data Sources: Connect your agent to external knowledge via documents, APIs, and databases
• Advanced Settings: Configure your context window size, temperature, and other parameters

🧠 Agent State Visualization (Right Panel)

The State Visualization panel provides real-time insights into your agent’s internal state:

• Context Window Viewer: Examine exactly what information your agent is currently processing
• Core Memory Blocks: View and edit the persistent knowledge your agent maintains
• Archival Memory: Monitor and search your agent’s external (out-of-context) memory store