Generative large language models (LLMs) have become crucial for modern NLP research and applications across various languages. However, the development of foundational models specifically tailored to the Russian language has been limited, primarily due to the significant computational resources required. This paper introduces the GigaChat family of Russian LLMs, available in various sizes, including base models and instruction-tuned versions. We provide a detailed report on the model architecture, pre-training process, and experiments to guide design choices. In addition, we evaluate their performance on Russian and English benchmarks and compare GigaChat with multilingual analogs. The paper presents a system demonstration of the top-performing models accessible via an API, a Telegram bot, and a Web interface. Furthermore, we have released three open GigaChat models in open-source, aiming to expand NLP research opportunities and support the development of industrial solutions for the Russian language.

Recent progress in Natural Language Processing (NLP) has driven the creation of Large Language Models (LLMs) capable of tackling a vast range of tasks. A critical property of these models is their ability to handle large documents and process long token sequences, which has fostered the need for a robust evaluation methodology for long-text scenarios. To meet this requirement in the context of the Russian language, we present our benchmark consisting of 18 datasets designed to assess LLM performance in tasks such as information retrieval, knowledge extraction, machine reading, question answering, and reasoning. These datasets are categorized into four levels of complexity, enabling model evaluation across context lengths up to 128k tokens. To facilitate further research, we provide open-source datasets, a codebase, and a public leaderboard associated with the benchmark.