Description
https://namespaces.chainagnostic.org/bip122/caip2#resolution-method :
To query for a Chain ID to represent or checksum a BIP122 reference, make a JSON-RPC request to the blockchain node with method
getblockhash
, for example:
[...]
The response will return as a result value the hash for the block with height 0 that should be sliced to its first 16 bytes (32 characters for base 16) to be compatible with the reference syntax defined above.
This is inconsistent with BIP 122 for forked chains:
The chain ID of a chain is the block hash of the corresponding genesis block. For forked chains, it's the block hash of the first block after fork.
So querying the hash will typically give the height of the fork, not height 0. Also, this method typically will not return any height if the chain has block hashes that are not expressed as 32 hex digits (or its nodes do not have a getblockhash
JSON-RPC method).