I Made Valet Damage Provable With GPS, Dual Timestamps, and SHA-256

When you hand your keys to a valet and the car comes back with a scratch, the burden of proof is on you. A photo you took on your phone is almost useless: there is no proof of when or where it was taken. I built CarShake to turn a before-and-after photo into a record that is hard to argue with.

The three layers of evidence

1. GPS. Every photo is stamped with where it was taken, so "that scratch was already there" meets "here is the geotag at the valet stand".
2. Dual timestamps. One from the device, one from the server. Timing that does not depend on a clock you could have set.
3. SHA-256 hashing. Each photo record is hashed and stored immutably, so once a record exists it cannot be edited later, by you or anyone else.

The before-and-after flow: photograph all four sides, wheels, windshield, and any existing damage before you hand over the keys. Repeat when you get the car back. A computer-vision pass flags new dents and scratches you might miss in bad light.

The "Instant Proof" trick that gets people in the door

The full product is a guided before-and-after capture. But there is also a free Instant Proof tool that just stamps date, time, and location on any photo in about thirty seconds. That single feature is the distribution: it is useful on its own, with no account.

Pricing is deliberately boring

The core capture flow is free. A $7 premium kit adds a printable checklist, a twelve-month photo log, and a shareable verification report. One-time, not a subscription. 200+ drivers have signed up for the free checklist.

This is a small, honest product for a specific fear: being charged for damage you did not cause. If you build in the evidence-integrity space, the lesson is that the boring parts (timestamp, geotag, hash) are the whole product.