Announcing Letta Client SDKs for Python and TypeScript Recent

Published: April 17, 2025 | Original Post

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Auto-generated client SDKs with unified documentation, introducing TypeScript support alongside Python.

What Changed

The team adopted an API-first approach using OpenAPI as a single source of truth and Fern to generate:

• REST API documentation
• TypeScript SDK
• Python SDK

Developer Benefits

• Complete feature parity between REST API and both SDKs
• Support for sync, async, and streaming interactions
• Consistent experiences across cloud and self-hosted deployments
• Potential for rapid language expansion

Technical Improvements

Streaming implementation handles both token and step streaming, plus async messaging for long-running agent invocations.

Engineering Impact

• Eliminated manual SDK maintenance
• Prevented API drift
• Accelerated feature development
• Improved quality assurance