LibraryPrivacy2023Design paperCorpus record
ERC-721 Multi-Metadata Extension
ERC 7160. 0xG , Marco Peyfuss.
ERC 7160, ERC-721 Multi-Metadata Extension. An extension to the ERC-721 standard to support multiple metadata URIs per token.
Status in the source: Final. A reading of the public specification, not a copy of it and not a certification.
ERC-721 Multi-Metadata Extension is worth reading for the rule it actually adds: An extension to the ERC-721 standard to support multiple metadata URIs per token.
- Evidence
- Primary paper
- Re-measured
- No
- Assumptions
- 3
- Records linked
- 4
Code
Source, repository, and what is actually hosted
- ERC 7160https://eips.ethereum.org/EIPS/eip-7160
- The source URL is not a GitHub repository. No code remote is invented.
- Full text is not mirrored. Public availability is not a licence to copy the file onto this site.
- Add to a reading list
01 Claim ledger
What the paper is allowed to say
Each row is a sentence already in the study. The status is the same on every row: a model claim, not a live measurement.
Claim 01 · Paper model
The rule
An extension to the ERC-721 standard to support multiple metadata URIs per token.
Claim 02 · Paper model
What was already failing
A signature that does not commit to what the user saw can be replayed into a different spend, a different chain, or a different message.
Claim 03 · Paper model
What the number does not mean
The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it.
Claim 04 · Paper model
What a builder should be able to point at
An implementation either constrains URI, MUST, NOT or it is a different design.
02 Three cuts
Observation, model, falsifier
A desk does not stop at the summary. Each claim is cut three ways, using only this study's own assumptions and checks. Nothing here is a new figure.
01 The rule
02 What was already failing
Observation
What the study says
A signature that does not commit to what the user saw can be replayed into a different spend, a different chain, or a different message.
Model
What has to hold
The object that has to change is URI, MUST, NOT. A neighbouring document with a similar name is not this one.
Falsifier
What would retire it
Can the same signature be replayed on another chain, account, or message?
03 What the number does not mean
Observation
What the study says
The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it.
Model
What has to hold
You are implementing ERC 7160 at the status the text itself states: Final.
Falsifier
What would retire it
Which primitive does the text require: URI, MUST, NOT?
04 What a builder should be able to point at
Observation
What the study says
An implementation either constrains URI, MUST, NOT or it is a different design.
Model
What has to hold
You are implementing ERC 7160 at the status the text itself states: Final.
Falsifier
What would retire it
What is covered by the signed bytes in ERC-721 Multi-Metadata Extension?
03 Sequence
One action, as an operating tape
- 01Open ERC 7160 and read the status line before the examples.
- 02Write down the rule in one sentence. A fair version of that sentence is: An extension to the ERC-721 standard to support multiple metadata URIs per token.
- 03Name the object that changes: URI, MUST, NOT.
- 04Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.
04 Load-bearing
The argument, and where a pitch drops it
What the text is allowed to settle
The cut
Ethereum Request for Comment 7160 can settle the shape of ERC-721 Multi-Metadata Extension. It cannot settle whether a later client, a later fork, or a later wallet still does this.
Why it carries weight
If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.
Where it is dropped
What this page will not pretend
The cut
There is no benchmark, no adoption number, and no claim that the mechanism is safe outside the assumptions written in the source.
Why it carries weight
If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.
Where it is dropped
The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it.
05 Register
What has to be true
Model · Not re-measured
You are implementing ERC 7160 at the status the text itself states: Final.
Model · Not re-measured
The object that has to change is URI, MUST, NOT. A neighbouring document with a similar name is not this one.
Model · Not re-measured
06 Divergence
What happened after the paper
The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it. Later documents can narrow, replace, or ignore this one. Cite the number you mean.
A later client, parameter set, or reward formula is a different object. Cite this paper for the mechanism. Cite a primary release for the network. This desk has not re-run the proof.
07 Pre-mortem
What to check before you use the idea
- 0 of 3 marked on this browser. A mark is a reading note, not a pass, a rating, or a recommendation.
08 Anatomy
The paper, in the order a builder needs
The problem it names
A signature that does not commit to what the user saw can be replayed into a different spend, a different chain, or a different message.
What the design proposes
- An extension to the ERC-721 standard to support multiple metadata URIs per token.
- It introduces a new interface, IERC721MultiMetadata, which provides methods for accessing the metadata URIs associated with a token, including a pinned URI index and a list of all metadata URIs.
- The extension is designed to be backward compatible with existing ERC721Metadata implementations.
How the mechanism is specified
- Taken from the specification, the next constraint is: It introduces a new interface, IERC721MultiMetadata, which provides methods for accessing the metadata URIs associated with a token, including a pinned URI index and a list of all metadata URIs.
- Locate URI, MUST, NOT in ERC 7160 and apply it to one transaction or call.
- Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.
What this page does not treat as proven
09 Lexicon
Terms, opened into the record
- ERC 7160
- The public text titled ERC-721 Multi-Metadata Extension.
- Final
- The document's own label for how finished the text is. It is not a market fact.
10 Repository
Every linked record on this page
Underlined words open a page that already exists: a concept, a protocol profile, a failure record, or another paper. If a word is not underlined, this desk does not have a record for it.
This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.
Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.