How Causius is built, and why
Legal work is slow because it is done by hand. Causius is an agent that does the work and a person who decides, built so what it handles stays private and what it claims can be checked.
Why build it
Most legal trouble is a letter with a deadline, a form or a contract: work with clear rules, billed by the hour because nobody automated it.
So Causius is a case file with an agent attached, not a chat. Lawyers stay where the law puts them; the rest gets done.
Five layers, one job each
- 01
Intake, in your browser
Letters and photos are read on your device. Names, addresses and numbers become placeholders before anything is sent.
- 02
The matter
One sealed record per matter: conversation, facts, deadlines, tasks, decisions, documents.
- 03
The agent
A loop of tools that searches, records deadlines and facts, and drafts. It may change the matter; anything that acts on the world it can only propose.
- 04
Models
Model-agnostic: a chain of free models, or your own key with one of ten providers. A better model is a setting, not a rewrite.
- 05
Identity and money
Causius keeps its own accounts (password, link, passkey, two-step codes) and lets OrangeCat sign you in. A lawyer's admission is published as a signed attestation that names the place, not the person.
What is real today
Each line says whether it works. The roadmap and changelog are public.
- Read an official letter
Paste or photograph it: what it asks, the deadline with its source sentence, a translation, a draft reply. No account.
Works today - Work a matter with an agent
One workspace per matter: conversation, sourced research, deadlines, tasks, drafts, documents.
Works today - Nothing leaves without your approval
Sending, filing, signing, sharing and paying wait for your decision.
Works today - Any model, including your own
Free shared models, or your own key with one of ten providers. The key stays in your browser.
Works today - Check a name before you found on it
The agent asks the domain registries whether a name is taken.
Works today - Legal assistants and lawyers
Assistants, lawyers and AI services list themselves under a name or pseudonym; a lawyer only where Causius checked the admission.
Works today - Found and register
Companies and associations prepared by the agent, filed on your approval.
Planned - Contracts that keep themselves
Agreements signed by the parties, obligations tracked, payment held in escrow if they choose.
Planned - Law as data, from Solon
Statutes and procedures as citable data, so every answer points at its rule.
Planned - Firms on their own models
Law firms run Causius on models inside their own walls.
Planned
Principles
A person approves what matters
The agent does the work; a person decides what leaves.
Nothing claimed that is not true
No invented statute, deadline, helper or testimonial. Causius gives legal information, not advice.
Open source
Every line is public under the MIT licence.
Built from shared parts
Design, sign-in, chat, models and the public record come from packages the whole fleet uses.
The stack
Boring where it can be.
- Framework
- Next.js 16 · React 19 · TypeScript, strict
- Data
- PostgreSQL · Drizzle · AES-256-GCM per matter
- Models
- @bitbaum/ai-kit · free chain · own keys · web search
- Sign-in
- @bitbaum/accountkit · OrangeCat OpenID Connect
- Conversation
- @bitbaum/chatkit
- Design
- @bitbaum/design-tokens
- Public record
- bip-kit · ROADMAP.md · CHANGELOG.md
- Rate limits
- limitkit
- Languages
- next-intl · English · German · French · Italian
- Tests
- Vitest · PGlite, a real PostgreSQL in process
- The problem
- Legal marketplaces rot the same way: clients want cheaper and faster, platforms attract hungry lawyers rather than the good ones, quality and trust fall, and AI on top just industrialises mediocre memos. Meanwhile Swiss SME employment and contract matters are frequent, document-heavy and repeat, yet each reaches a lawyer as an unstructured pile the lawyer bills hours to untangle.
- What Causius does about it
- Causius prepares the mandate. A licensed lawyer owns it. Intake turns a messy SME employment or contract matter into a structured file: timeline, clause map, missing documents, first draft and a risk list with citations to Fedlex and case law. A curated bench of named lawyers accepts, edits and bills it. A factory for prepared files, not a lawyer directory or a substitute counsel; it never says 'you should sue'.
From letters to legal existence
Causius holds legal work: matters, founding and registering, contracts. The law itself belongs in Solon, as data every product can cite. Next, helpers are paid through OrangeCat.