CASUS is a Swiss legal AI platform that works directly as a Microsoft Word add-in. Contracts are analyzed, assessed, and revised where they are created - without switching to an external tool. Hosting in Switzerland and the EU, Zero Data Retention, and no transfer of data to the US are technical requirements built into the platform, not optional settings.
Why is contract work still done outside of Word?
Many legal AI solutions follow the same pattern: export the document, upload it to an external tool, read the analysis, manually transfer results back. That process sounds like a minor inconvenience. In practice, it costs time, introduces errors, and breaks concentration at exactly the moment when focus matters most.
This has historical roots. The first generation of legal software was database and research software - not a drafting tool. Word remained the center of document work while analysis and research happened elsewhere. That division has proved stubborn, even though there is no longer a technical reason for it.
For Swiss law firms and in-house teams, there is an additional dimension: data protection. When documents are transferred to external systems for analysis - particularly to US-hosted platforms - questions arise about confidentiality and compliance with the Swiss DSG and the GDPR. Many teams accept this quietly, even though it is avoidable.
What a legal AI Word add-in actually changes
A legal AI Word add-in removes the separation between analysis and editing. The document stays open. The AI works inside it, not alongside it.
That sounds like a technical nuance, but it has practical consequences. Improvement suggestions can be applied directly, correctly formatted, without copy-paste. Clauses are inserted at the right place, with the numbering and structure of the original document intact. Anyone who reads a risk analysis and wants to edit the affected section at the same time does not have to switch between two applications.
This is not a comfort argument. It is a quality argument. Errors often arise when transferring analysis results manually into the contract. An integrated system eliminates that step.
Those who want an overview of what AI-assisted contract review directly in Word can do will quickly see where the difference from web-only tools lies.
How CASUS implements the Word integration
CASUS, a Swiss legal AI platform, is available as a Microsoft Word add-in and combines several analysis and editing functions in a single interface.
Risk analysis with a party perspective
The Risk & Quality Review identifies risks and weaknesses in a contract, assigns them to the contracting parties, and prioritizes them by severity (low / medium / high). Each finding includes concrete drafting options. These can be applied directly in Word - with the correct formatting of the source document, without manual rework.
Comparison with an internal playbook or best practices
The Benchmark workflow checks a document against a reference standard. That can be the firm's own playbook or an established market standard, for example for NDAs, SPAs, or DPAs. The result shows missing clauses, incomplete provisions, and deviations - with a percentage score for the match. Missing clauses can be inserted directly at the right place.
AI Chat and Agent Mode
The AI Chat answers questions about the document and links answers to the relevant passages. In Agent Mode, it executes changes directly in the document: inserting clauses, rewriting text, checking consistency across the entire document. Document structure and numbering are preserved throughout.
Proofreading before sending
The Proofread module checks spelling, grammar, and terminology consistency, verifies cross-references and definitions, and finds placeholders or open fields. It is not a legal review of the legal situation - it is a quality check of the document itself.
Anyone who wants to try CASUS can register directly at app.getcasus.com/signup and test the platform for free - without a prior demo or contractual commitment.
What Swiss law firms and in-house teams can expect in practice
The practical difference between a web-only tool and a Word add-in is most visible in recurring tasks: reviewing NDAs, checking standard contracts against playbooks, cleaning up pleadings before filing.
With web-only tools, there is always the moment when analysis and editing fall apart. The analysis result is in the browser; the document is in Word. Anyone who wants to apply an improvement suggestion at that point has to copy, paste, and reformat. With an add-in, that step disappears.
For in-house teams, there is a further consideration: consistency. When several people work with the same contract type, the Benchmark workflow can help maintain uniform standards - not as a requirement, but as a reference point. That reduces dependence on whether the most experienced person on the team happens to be available.
On the data protection side: CASUS hosts in Switzerland and the EU, does not transfer data to the US, and offers Zero Data Retention and No Human Review. Teams analyzing sensitive contracts do not need to treat these points as an additional problem. More on the technical security measures is available on the CASUS security page.
Legal AI Word add-ins compared
In the international market, providers like Legora, Harvey, LegalOn, and Noxtua also offer Word add-ins. The core functions are similar: risk analysis, playbook review, chat interaction with documents, and redlining.
The differences are in the details. Harvey reports that customers such as Talanx achieved up to 60 percent faster review times using the Word add-in for certain tasks. LegalOn puts the time saving in contract review at 85 percent. These figures refer to specific use-case scenarios and cannot be generalized.
For Swiss teams, the location factor matters too. Many international providers host in the US or rely on US AI infrastructure. For law firms and in-house teams subject to the Swiss DSG or the GDPR, that is a relevant difference - not only formally, but also in client communications.
CASUS is positioned as a Swiss alternative, with a focus on Swiss and EU hosting and the data protection measures described above.
Try CASUS
CASUS is available as a Microsoft Word add-in and as a web app. Anyone who wants to test the platform without a contractual commitment can register for free at app.getcasus.com/signup. The functions - Risk & Quality Review, Benchmark, AI Chat, Proofread, and more - are available directly in Word, with hosting in Switzerland and the EU.
FAQ
What is a legal AI Word add-in?
A legal AI Word add-in is an AI-powered extension for Microsoft Word that integrates legal functions directly into the word processor. Typical features include risk analysis, playbook comparison, clause insertion, and proofreading - without needing to export the document to an external tool.
Why does Word integration matter for legal teams?
When AI analysis and document editing happen in the same interface, there is no manual transfer of results. That reduces copy-paste errors, saves time, and keeps the workflow intact. For teams handling high document volumes, this makes a measurable difference day to day.
What data protection standards apply to CASUS?
CASUS hosts in Switzerland and the EU. No data is transferred to the US. The platform offers Zero Data Retention and No Human Review (abuse monitoring opt-out). That makes it relevant for law firms and in-house teams subject to the Swiss DSG or the GDPR.
What can CASUS AI Chat do in Agent Mode?
In Agent Mode, AI Chat executes changes directly in the Word document: inserting clauses, rewriting text, and checking consistency across the document. It respects document structure, numbering, and formatting, and places changes at the right location.
What is the difference between Risk & Quality Review and Benchmark in CASUS?
Risk & Quality Review analyzes a document for risks and weaknesses from each party's perspective. Benchmark checks whether a document meets a reference standard - for example, the firm's internal playbook or market standards for NDAs or SPAs. Both workflows provide improvement suggestions that can be applied directly in Word.
How does CASUS differ from competitors like Harvey or Legora?
Functionally, the core modules are comparable. The main difference is in hosting and data protection: CASUS hosts in Switzerland and the EU, while Harvey and Legora use US or other international infrastructure. For Swiss law firms and in-house teams, that is a relevant factor when choosing a provider.
Can CASUS handle the review of many documents at once?
Yes. The AI Data Room allows uploading dozens or hundreds of documents. Content is extracted in parallel and output as a table - suited for due diligence, compliance checks, and clause matrices. Extraction follows user-defined fields and prompts.
Is Proofread in CASUS a legal review?
No. The Proofread module is a quality and consistency check of the document: spelling, grammar, terminology, cross-references, definitions, and placeholders. It does not replace a legal review of the legal situation, but it substantially reduces formal errors before a document is sent.
