Ninefold is an API operated by Best Pay LLC. You seal a record onto your own WORM ledger and, after Best Pay anchors the batch, you download a Best Pay Receipt for it. Anyone can check that receipt with the published public key.
The yearly plan is $490 and includes 6,000 seals. The monthly plan is $49 and includes 500 seals. A seal past the allowance is refused, not billed. Cancel in the billing portal. Access to new seals runs through the day you already paid. Receipts you already took keep verifying. The ledger is not deleted when the year turns or when you cancel.
Send the SHA-256 of a document. Do not send the document. A valid receipt means those bytes and the signature still match. It does not mean the document is true.
Questions: cs@bestninefold.com. The commercial terms are a draft and have not been reviewed by a lawyer.