Jus Mundi

What it is

Jus Mundi is a Paris-founded (2019) research database for international arbitration and international law, and Jus AI is the research agent that runs on top of it. The corpus is the point: awards, decisions, treaties and institutional rules gathered through partnerships with more than 100 arbitral institutions, publishers and associations, including the IBA, ICC, AAA-ICDR, LCIA, SIAC and HKIAC, with commentary from publishers such as Oxford University Press, JURIS and Brill. Jus AI answers questions against that corpus and links each authority back to the source document on Jus Mundi. The company says it serves more than 700 arbitration teams and over 150,000 users in more than 90 countries; named customers include Freshfields, Quinn Emanuel, Three Crowns, White & Case and WongPartnership. It raised a $22M Series B in September 2024 and is independent.

The engine changed twice in 13 months. Jus AI 2 (September 2025) added a planning agent that builds a multi-step research plan per query. Jus AI 3 (14 October 2026) checks its own findings and runs follow-up research before answering; on the vendor’s 114-prompt comparison against Jus AI 2 it was 19% faster to first answer, with 10% more answers scored perfect on relevance and 8% more on faithfulness. Both benchmarks are Jus Mundi’s own.

Why it shows up in Legal Ops stacks

• It is the arbitration corpus that general legal AI tools now rent. Legora announced the first agent-to-agent integration with Jus AI on 26 March 2026, with White & Case named as the first joint customer, and Harvey announced the same pattern on 4 November 2026: Jus AI inside Harvey Assistant, Agents, Vault and Workflows for joint customers, at no added cost, by the end of 2026. When the two fastest-growing legal AI platforms plug in Jus AI rather than building arbitration coverage, that is the market’s answer on corpus depth.
• It reaches Claude directly. The Jus AI connector for Claude launched on 30 July 2026 and is listed in the Claude Connectors directory as “Jus AI (Light) by Jus Mundi”. A team that already runs Claude for Legal can pull cited arbitration authority into the same conversation where it drafts the memo, without a second interface.
• Research ends in a decision, not a stack of PDFs. Arbitrator search and due diligence, built on Jus Connect profiles and the Conflict Checker, entered private beta on 27 October 2026, so the same subscription is moving toward tribunal selection work.

Pricing reality

Jus Mundi publishes no list price for its commercial plans. The pricing page sells tiers rather than seats; Jus AI is not sold on its own and comes only with the AI tiers, which the July 2026 connector release names AI Core and AI Max. The help centre says firm pricing is set by the size of the team, not by the number of named users, and that individual subscriptions are reserved for solo practitioners and barristers’ chambers. Basic access to collected documents is free, and the help centre describes a 7-day free trial of the premium features.

The only published number is academic: Brill lists the Jus Mundi Academic Research subscription at €2,350 / US$2,650, without stating the billing period. Treat that as the floor for an institutional seat, not a firm quote. In March 2026 Jus Mundi added a single-user Jus AI licence for academic libraries, which tells you the AI tier is priced separately from the database. For a firm, expect a team-sized annual contract with the AI tier and any add-on libraries (JURIS, Oxford University Press) as separate lines. Ask for each line itemised.

Best for

Arbitration and investment-treaty practice groups, from boutique to Global Arbitration Review 30, whose associates need answers cited to awards, treaties and institutional rules they can open and check. It also fits the knowledge lead at a firm that has standardised on Harvey or Legora and wants arbitration depth inside that tool rather than a second login.

Skip it if arbitration is a side practice. A firm that sees two or three international disputes a year will not use a dedicated arbitration subscription enough to justify it; Westlaw Advantage or Lexis+ AI with Protégé plus the free public treaty and award databases cover occasional work.

Versus the alternatives

Kluwer Arbitration from Wolters Kluwer is the incumbent pole: deep commentary, the Kluwer Arbitration Blog and an AI assistant launched in late 2025 that answers from its own content. Pick it when treatise and commentary depth matters more than award and treaty coverage, or when it is already in the firm library budget. Thomson Reuters CoCounsel and Lexis+ AI with Protégé hold the largest general-research share; pick one when disputes are mostly domestic litigation with occasional arbitration. Legora and Harvey are the fastest-growing entrants, and both now route arbitration questions to Jus AI, so the real choice is often Jus AI direct versus Jus AI through your existing platform. Pick the platform route when your lawyers already live in it; pick Jus Mundi direct when you need the full research modes, the arbitrator tools, or you have no platform. vLex Vincent AI fits multi-jurisdiction national-law research better than arbitration.

Watch-outs

• The Claude connector runs Light mode only. Jus AI offers Auto, Light, Think and Deep modes on its own site, but the Claude connector exposes Light, built for quick queries. Guard: use the connector for fast cited lookups and send matter-level research to Think or Deep on jusmundi.com before anything reaches a pleading.
• The headline quality numbers are the vendor’s. The Jus AI 2 and Jus AI 3 benchmark figures come from Jus Mundi. Guard: run the trial on two closed matters where a partner already knows the answer, and score Jus AI’s citations against that work before you sign.
• Partner integrations are not all live. As of the announcements, the Legora integration was promised for later in 2026 and the Harvey integration for year-end, both requiring a Jus AI plan on top of the platform subscription. Guard: confirm in writing which integration is live for your named users and that the platform route does not need a second Jus AI contract.
• Plan names have moved. Older pricing materials list Essentials and AI Premium; the 2026 connector release says AI Core and AI Max. Guard: get the exact tier and its included modes, connector access and add-on libraries written into the order form, not just the plan name.