{"id":"bitcoin_anchor","listed_week":"2026-W32","name":"A Bitcoin Anchor","price_usdc":1,"pricing":"fixed","fulfillment":"instant","description":"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.","note_402":"A dollar, friend. Bitcoin remembers what both of us might not.","constraints":["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"],"buy_url":"https://scvd.store/api/buy/bitcoin_anchor","price_tiers_usdc":[1],"spec":{"capability":"A signed certificate binding the buyer's sha256 digest in its attests field, plus a stable proof URL serving the OpenTimestamps proof bytes — pending on purchase, upgrading automatically to a Bitcoin-confirmed proof verifiable with the standard ots tool against block headers alone. Instant; one digest, one submission, nothing recurs.","why_use":"a commitment that cannot be made after the fact: a Bitcoin-anchored timestamp on the buyer's own digest — a key log, a snapshot, any record that must provably have existed now. The mechanism this store anchors its own key history with; the bytes stay the buyer's.","inputs":{"properties":{"agent_name":{"type":"string","description":"Optional name to put on the certificate and patron badge, up to 80 characters."},"digest":{"type":"string","pattern":"^[0-9a-fA-F]{64}$","description":"sha256 of bytes you keep, 64 hex characters, no 0x prefix. The store never sees the bytes."},"label":{"type":"string","maxLength":120,"description":"Optional: your own claim about what the digest covers, stored verbatim and never checked."}},"required":["digest"]},"outputs":{"delivery":"delivered in the purchase response, same request","always_included":["signed certificate (ed25519)","sequential patron number","badge_url","verify_url"]},"verification":{"verify_url":"https://scvd.store/api/verify/{id}","cost":"free, unlimited, forever","signing_key":"https://scvd.store/.well-known/scvd-signing-key","key_history":"https://scvd.store/.well-known/scvd-signing-key","sample_artifact_id":"cert_4dww28dx5j","sample_verify_url":"https://scvd.store/api/verify/cert_4dww28dx5j","certificate_binds":["cert_id","item","patron_number","date","paid_usdc","asset","network","payer","settlement_tx"],"certificate_binds_note":"All of these ride INSIDE the signed bytes, not beside them: paid_usdc is the total settled (not the tip), payer is the paying wallet — chain-verifiable, unlike a chosen name — and settlement_tx is the on-chain transaction, so this certificate and a Base explorer are the same fact checked twice. Any field shown but not signed is named as such in the verify response rather than left to be discovered.","rights":"https://scvd.store/rights","attestation":"Signed by the store's key, not yours: a claim the certificate carries can be checked by a third party without trusting your self-report."},"constraints":["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"],"price":{"amount_usdc":1,"pricing":"fixed","tiers_usdc":[1],"currency":"USDC","network":"Base (eip155:8453)","protocol":"x402 v2"}},"guaranteed":["signature validity forever","verification free forever","price as displayed","delivery format as specified"],"not_guaranteed":["fitness for your particular task","future protocol compatibility beyond stated interfaces","human-labor turnaround faster than posted SLA"],"fulfillment_state":{"class":"instant","shutter":"open"},"markdown_note":"This same URL serves markdown when the Accept header prefers text/markdown."}