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ERC-7857 (RFC)

ERC-7857 is an NFT for an agent whose important files are private. The files stay encrypted. The chain keeps hashes, which are fingerprints of those files. A transfer is supposed to re-lock the same files for the new owner and prove that handoff.

The spec is Final. Final means the text is stable. A deployed contract can still be written badly. Read the contract you are buying.

How a private handoff works

Think of a locked diary. The sale includes a new key for the buyer and a proof that the same diary was re-locked for them. The seller may already have read it. No proof can make them forget.

1. Fingerprints, not the raw files. The model, the memory, or the character file sits off the chain, encrypted. The token stores hashes so you can tell if the file changed.
2. Transfer. A transfer moves the token and publishes a key sealed for the new owner. The check is that the sender knew the old data, that it was re-encrypted for the receiver, and that the new fingerprints match.
3. The receiver signs too. The proof includes the receiver’s signature, so they confirm they can see the data that was offered.
4. Clone is a copy, not a sale. A clone makes a new token with copied data. The original owner keeps the original token. You are not selling the parent when you clone.
5. Two ways to prove it. One design uses a secure chip, called a TEE. Another uses a zero-knowledge proof. With a proof, later updates may still be visible to a past owner unless the data is re-encrypted again. The chip design can keep a multi-party key. Read which one the project uses.

What ERC-7857 does not do

• It cannot prove the seller erased their copy or forgot what they read.
• It does not run the agent. It moves access to encrypted data.
• It still needs storage, key management, and a verifier. The standard is the check, not the hard drive.
• Privacy depends on that design. Final does not mean every project is private.

Professional use

• A specialist can sell an agent whose private notes or model should not be posted in the open.
• The buyer gets a checkable handoff instead of a zip file in email.
• You should still assume the seller has seen the old files.

Business use

• A company can move an internal agent to a buyer without putting the raw files on a public website.
• A clone can make a second copy for another department while the original token stays put.
• Legal rights to the model still belong in the contract you sign. The token is the technical handoff.

Personal use

• A private journal character can be sold with the encrypted pages, not a public paste.
• You can clone a copy for a friend and keep your own token.
• You pay network fees for the proof and the transfer. The files themselves are not magically inside the token.

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