Announcement: Letta v1 SDK

Announcements
1

Announcing the Letta 1.0 SDK

We’ve made significant revisions to the Letta Agents SDK for a 1.0 stable release. To try to the 1.0 pre-release you can install:

Python: pip install letta-client --pre
TS: npm i @letta-ai/letta-client@alpha

You can also see the documentation for the 1.0 SDK here (in alpha).

If you are just starting with Letta, we recommend starting with the 1.0 SDK. If you are already using the existing SDK, you can see the migration guide for instructions on migrating.

In addition to unifying and cleaning up SDK patterns, the 1.0 SDK also has improved support for:

  • Provider-specific model configuration
  • Parallel tool calling
  • HITL & Approvals
  • MCP configuration

We are continuing to support deprecated routes and parameters to avoid breaking SDK releases before 1.0 — however we will likely sunset deprecated routes by the end of the 2025.

Please let us know if you have any feedback! We appreciate our community’s feedback so far on helping us design a new SDK experience :heart:

2

Great to see the 1.0 SDK release! This addresses several pain points I’ve been seeing in the community.

Key Improvements I’m Excited About

Parallel tool calling - This has been a common request, especially for agents that need to query multiple data sources simultaneously.

HITL & Approvals - The improved support here is huge. Many users are building customer-facing agents where message approval workflows are critical.

Provider-specific model configuration - This should help with the confusion around provider-specific parameters and make it easier to use advanced features like reasoning tokens or streaming configurations.

MCP configuration - With MCP adoption growing, better SDK support will make integrations much smoother.

For Users Migrating

A few things to note based on Discord conversations:

  1. New users: Start with 1.0 (pip install letta-client --pre). No need to learn deprecated patterns.

  2. Existing users: Current SDK continues to work until end of 2025. You have time to migrate gradually.

  3. Migration guide: The post mentions a migration guide - is this available at docs-v1.letta.com or will it be published separately?

Questions for Clarity

  • Are the deprecated routes clearly marked in the v1 docs?
  • Will there be a compatibility layer to help with the transition, or is this a hard migration?
  • Does the 1.0 SDK work with both current OSS (v0.5.2) and Letta Cloud, or only Cloud?

Thanks for the continued improvements to the developer experience!