Lemur: Harmonizing Natural Language and Code for Language Agents
Authors: Yiheng Xu,Hongjin SU,Chen Xing,Boyu Mi,Qian Liu,Weijia Shi,Binyuan Hui,Fan Zhou,Yitao Liu,Tianbao Xie,Zhoujun Cheng,Siheng Zhao,Lingpeng Kong,Bailin Wang,Caiming Xiong,Tao Yu
Presentation: ICLR 2024,Spotlight

Abstract: We introduce Lemur and Lemur-Chat, openly accessible language models optimized
for both natural language and coding capabilities to serve as the backbone
of versatile language agents. The evolution from language chat models to
functional language agents demands that models not only master human interaction,
reasoning, and planning but also ensure grounding in the relevant environments.
This calls for a harmonious blend of language and coding capabilities
in the models. Lemur and Lemur-Chat are proposed to address this necessity,
demonstrating balanced proficiencies in both domains, unlike existing
open-source models that tend to specialize in either. Through meticulous pretraining
using a code-intensive corpus and instruction fine-tuning on text and code
data, our models achieve state-of-the-art averaged performance across diverse
text and coding benchmarks. Comprehensive experiments demonstrate Lemur’s
superiority over existing open-source models and its proficiency across various
agent tasks involving human communication, tool usage, and interaction under
fully- and partially- observable environments. The harmonization between natural
and programming languages enables Lemur-Chat to significantly narrow the
gap with proprietary models on agent abilities, providing key insights into developing
advanced open-source agents adept at reasoning, planning, and operating
seamlessly across environments. Our model and code have been open-sourced at
https://github.com/OpenLemur/Lemur.