Casus Legal is a Russian case-law research platform for lawyers, researchers, and AI systems that need structured access to verifiable judicial sources. Its specialised collections cover the Constitutional Court, Supreme Court, historical Supreme Commercial Court, Intellectual Property Court, and all ten commercial cassation districts. The platform also provides dedicated collections for administrative and criminal-law practice.

Users can research legal questions, statutory provisions, doctrines, and terms through semantic and lexical search, then review decisions with case metadata, court hierarchy, doctrinal context, and links to full texts. Citations point back to the original Russian-language judicial acts, which remain the authoritative sources. Coverage of higher-court practice spans 1992–2026.

Casus Legal offers a web application and an authorised remote MCP connection for compatible AI assistants and research workflows. Access through MCP is limited to the corpora available to each account. The service also provides coverage information, case-law reviews, research examples, setup guides, and team licensing. English navigation is available, while English summaries, terminology, and on-demand translation are being introduced progressively.