Status
- The demo app is live at app.tieout.workers.dev, no sign-in: a synthetic building services contractor (Kronfeld Haustechnik) with five projects. Each find (Fund) shows its amount, its calculation and its original documents; a person checks and releases it, and released finds go into the final invoice (Schlussrechnung) with an evidence package. Rebuilt from zero since 23 October 2026 (v2); plan and progress in
docs/_STATUS.md.
- The hackathon version (v1) is archived at app-v1.tieout.workers.dev. Its code is frozen under the tag
v1-archiv (app code, architecture and tech stack in the v1 README).
The problem
On a construction site, more gets built, changed and agreed verbally than ends up on the final invoice: hourly work without a signature, extra quantities, changes ordered by email or WhatsApp. The evidence is scattered across inboxes, plans, photos and people's heads. At the same time, general contractors increasingly check invoices with software and cut whatever lacks evidence.
What tieout does
tieout brings everything a contractor knows together in a digital twin: on top, the business (clients, contracts, price base, all projects); below, every project down to the single line item and its evidence. The first application built on it is the final invoice: tieout reconciles what was ordered, built and invoiced, and finds what is missing. Every line backed by evidence.
- Your data. Systems (ERP invoices, estimating prices), documents (plans with revision index, bill of quantities, measurements, timesheets) and communication (email instructions, WhatsApp messages, photos, voice notes from the site).
- The digital twin. The business layer (clients, contracts, price base, projects) and the project layer (every line item as ordered, built, invoiced, open). Every value carries its source and a review state; nothing is overwritten.
- The result. A final invoice that finds forgotten hours, extra quantities and plan changes, is pre-checked the way the client would check it, and has evidence for every line. A human decides on every line; nothing is invoiced automatically.
Principles: AI delivers facts with a source, a human confirms. The invoice itself is deterministic code. Every number links to its original document. Every business has its own data silo. Synthetic data only until the legal review is complete.
Repository layout
.
├── app/ v2 app (Next.js), from step 1 of the rebuild
├── kern/ v2 calculation and data model, from step 2
├── agent/ WhatsApp agent: fitters report work by text, voice note or photo
├── website/ public website (Next.js, DE/EN)
├── brand/ logo and LinkedIn graphics, generated by script
└── docs/ status, handover, specification, design, clean-up log, demo cases (solution list)
Node 22 or newer. Every change goes through a branch and a pull request to main. Working rules: CLAUDE.md.
Team
