General specifications
Namecoin blockchain domains basically follow the standard specifications for ICANN domains with TLDs (top level domains) such as .com, .net and .org, as described detailed in section Domain specification and following. Beside directing to a server, all Namecoin domains may contain (alternatively or additionally) personal contact data as values, which are resolved by our browser add-ons and the connected
Asset Viewer. This implementation and extension of the standard domain specifications was introduced in September 2022 and follows repeated and strong requests from the Namecoin community.
If a record contains IPv4, IPv6, name server, domain delegation or redirection data, the name is resolved as a DNS record; otherwise, it is handled as an identity record and shown in the Asset Viewer. Names containing an underscore are treated as ID records only. The maximum length for domain and ID records is 63 characters excluding the TDL (253 characters including subdomains, dot separators and TLD). Records exceeding this limitations won't be resolved. The following table shows the possible characters:
a-z |
Latin lowercase alphabet
Uppercase letters will be auto-converted to lower case (uppercase blockchain records are invalid and won't be resolved) |
0-9 |
Numbers
Position anywhere in the name (name may start or end with numbers and may contain numbers only) |
- |
Hyphen
Not at the beginning or end of a name/subdomain, only one hyphen as separator between alphanumeric characters (exception for Punycode prefix
xn--) |
_ |
Underscore
For ID records and subdomains only. Not at the beginning or end of an ID, only one underscore as separator between alphanumeric characters (multiple underscores may be taken for multipart names)
|
In general, the syntax for ID records follows the specifications introduced for the
id/ namespace in May 2012. Accordingly, and in line with the basic domain specifications, the data are formatted as JSON data with key/value pairs, placed between semicolons and enclosed in curly braces, for instance:
{ "name": "John Doe", "email": "john@doe.example", "bitmessage": "BM-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxz", "website": "https://doe.example", "bitcoin": "1xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", "namecoin": "Nxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" }
Typical data written to the Namecoin blockchain are name, e-mail,
Bitmessage address and wallet addresses. It makes no difference whether the data is separated by a space or not. In addition to the standard fields originally introduced, any other key records may be taken and are resolved by the browser add-ons. Three nested JSON levels (sub trees) are resolved by the Asset Viewer. The example in the screen capture shows the ID record
domob.web3 of Daniel Kraft (the main coder of the Namecoin Core wallet), which has two JSON levels. This primarily implements
JSON-LD (Linked Data) specifications, which are taken (outside of the blockchain space) for documents or server-side to the source code of websites, e.g. in order to get the data listed in public directories.
Web3 Identities
The connected
Asset Viewer, accessible via our browser add-ons, enables your blockchain-based digital business card. Next to the domain name resp. identity, a so-called identicon is displayed, which is generated from the SHA-256 hash of the cryptographic asset’s name on the blockchain with its namespace prefix. The cryptographic function of signing temporary login tokens etc. allows passwordless
OpenID web logins and identity verification. The Namecoin domain and ID record thus enables decentralized Web3 authentication. For details on the technical implementation, please refer to the corresponding section
Verifying ownership.
Extended ID records
The technical size limit for an ID record’s data value is 520 bytes (equivalent to 520 ASCII characters). While this is sufficient for a few social media links, it is quickly exceeded when expanded to include usernames, user IDs, community memberships, and other information. To allow for more flexible use of Namecoin’s blockspace, such as publishing larger structured text and links, the
NMC-V+ Standard was introduced. This standard allows data to be split across multiple records within the asset’s update history.
For an example of an ID record exceeding 520 characters, refer to the ID
namecoin.nmc.
Non-Fungible Tokens
While the cryptographic asset of a blockchain record is a non-fungible token (NFT) itself and can be used as a utility asset, a classical NFT may contain on-chain data or a link to external media. For the different methods and standards, please refer to the dedicated section
Specifications as well as the
landing page of the affiliated auction platform.
