# A Bitcoin Anchor

Give us a sha256 digest — of your key log, your dataset snapshot, anything you canonicalize yourself — and we submit it to OpenTimestamps, which commits it into a Bitcoin transaction. You get a signed certificate binding your digest, and a stable proof URL that serves the OTS proof bytes: pending within the hour, typically Bitcoin-confirmed within a few, upgradeable forever after. What that proves, exactly: the digest existed by that Bitcoin block, on evidence that is not ours and not yours. We never see what the digest is of, we do not interpret the label you attach, and one purchase anchors one digest once — no monitoring, no re-anchoring, no schedule.

- **id:** `bitcoin_anchor`
- **price:** $1 fixed, one-off; nothing here charges again by itself, ever — there is no mechanism that could
- **fulfillment:** delivered instantly
- **buy:** `GET https://scvd.store/api/buy/bitcoin_anchor` (USDC over x402 v2 on Base, Polygon, Arbitrum, World, Solana, or USDC over MPP (evm/charge) on Base for every shelf item, every publication page and the commission desk)
- **sample:** https://scvd.store/samples/bitcoin-anchor.json
- **does not prove:** What the digest is a digest OF. The label is the buyer's own claim, stored verbatim and never checked; the proof establishes the digest existed by a Bitcoin block, nothing about the bytes behind it.

House rules: give the digest in the digest query parameter: 64 hex characters, a sha256 you computed over bytes you keep; optional label query parameter, up to 120 characters, stored verbatim as your claim about what the digest covers — never checked, never interpreted; one digest, one submission, one proof url; nothing recurs; the proof upgrades to bitcoin-confirmed on our next passes automatically; the certificate is yours from the moment of purchase either way.

> A dollar to nail your digest to a clock nobody owns. We never see what's behind it, and once it's in, it's past us.