LongCat API Platform Change Log

Version: 2025-12-22

LongCat-Flash-Chat Update

• The LongCat-Flash-Chat model has been upgraded to a new version. This update involves model capability enhancements only. The model name and API invocation method remain unchanged.

• Building upon its principles of “extreme efficiency” and “lightning-fast responsiveness,” the new version of LongCat-Flash-Chat further improves its context handling and programming capabilities:

  • Significantly enhanced programming performance: Deep optimizations for developer-oriented use cases, with substantial improvements in code generation, debugging, and code explanation tasks. Developers are encouraged to prioritize evaluation and testing.
  • Support for a 256K ultra-long context length: The context length has doubled compared to the previous generation (128K), enabling efficient processing of large documents and long-sequence tasks.
  • Comprehensively strengthened multilingual capabilities: High-quality support for nine languages, including Spanish, French, Arabic, Portuguese, Russian, and Indonesian.
  • More robust Agent capabilities: Improved stability and efficiency in complex tool invocation and multi-step task execution.

• For API usage details, please refer to the LongCat API Platform Interface Documentation.

Version: 2025-09-22

LongCat-Flash-Thinking Release

• LongCat-Flash-Thinking is officially released and open-sourced simultaneously. It is a deep-thinking model which you can chat with for free on LongCat Chat or call via the API by specifying model=LongCat-Flash-Thinking.
• LongCat Chat URL: https://longcat.chat/
• For calling instructions, please refer to: LongCat API Platform API Documentation
• Open-Source Platforms:
  • Hugging Face: https://huggingface.co/meituan-longcat/LongCat-Flash-Thinking
  • Github: https://github.com/meituan-longcat/LongCat-Flash-Thinking

Version: 2025-09-05

LongCat API Platform Launch

• The LongCat API Platform is now live, supporting API calls to the LongCat-Flash-Chat model. You can call it by specifying model=Longcat-Flash-Chat.
• For calling instructions, please refer to: LongCat AI Platform API Documentation

Version: 2025-08-29

LongCat-Flash-Chat Release

• LongCat-Flash-Chat is officially released and open-sourced simultaneously. It is a high-performance, general-purpose conversational model that you can chat with for free on LongCat Chat.
• LongCat Chat URL: https://longcat.chat/
• Open-Source Platforms:
  • Hugging Face: https://huggingface.co/meituan-longcat/LongCat-Flash-Chat
  • Github: https://github.com/meituan-longcat/LongCat-Flash-Chat