Built out of frustration.
Opened to everyone.
The story behind PreSignCheck.
Hi — I'm Colin, a CTO based in Mariposa, California. Over the years I've found myself reviewing contracts constantly: NDAs before partnerships, freelance agreements before projects, vendor terms before signing up for services.
The question is almost always the same: is there anything in here I should be worried about? Getting a lawyer to answer that costs hundreds of dollars and takes days. Reading it yourself means hoping you catch the one buried clause that matters.
So I built PreSignCheck for myself — an AI tool that reads contracts the way an initial attorney review would, flags the risks in plain English, and gets out of the way in minutes not days. It worked well enough that I decided to open it to others.
If you're a founder, freelancer, consultant, or just someone who signs things and wants to understand what they're agreeing to before they sign it, this is for you.
The technology
PreSignCheck runs on Claude, Anthropic's most capable AI model. Claude consistently ranks at the top of independent benchmarks for legal and contract reasoning — the same model trusted by enterprises including Amazon, Google, and Salesforce. Your documents are encrypted, analyzed in isolation, and permanently deleted after your report is generated. We never store content or train on your data.
What I'd love from you
I built this to scratch my own itch, but the most useful thing now is hearing how other people use it — what's working, what's missing, what you'd pay more for. Every piece of feedback directly shapes what gets built next.