Quantus Namespace - Chains

CAIP-2

For context, see the CAIP-2 specification.

Rationale

Quantus Network runs a small, fixed set of networks operated by one team: a production mainnet and a public testnet. Chains in the quantus namespace are therefore referenced by name, following the approach of the hedera and sui namespaces, rather than by a genesis hash prefix.

A name is stable even if a testnet is reset with a new genesis block, while the genesis hash behind it changes. Clients that need cryptographic assurance that an RPC node belongs to the named network resolve the name to a genesis hash as described below.

Syntax

The reference is one of the following enumerated, case-sensitive strings:

• mainnet - Quantus mainnet
• planck - Planck, the public testnet

New networks are added by amending this profile. A regular expression that matches the identifiers currently defined is:

^quantus:(mainnet|planck)$

A regular expression that matches any identifier this namespace could define in the future, within the CAIP-2 limit of 32 characters, is:

^quantus:[a-z0-9]{3,32}$

Resolution Method

Each name resolves to the hash of block 0 of that network:

To verify that an RPC node belongs to a given network, make a JSON-RPC request with the method chain_getBlockHash and block number 0, and compare the result with the table:

// Request
{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "chain_getBlockHash",
  "params": [0]
}

// Response from a Quantus mainnet node
{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "0xfb5487c0be6ae4ade2d41d16e50465129861636c2b8d61fa94d7a19631626fba"
}

The system_chain method returns the human-readable chain name and can be used as a first, non-cryptographic check.

Note that Quantus block hashes are computed with the Poseidon hash function, so the genesis hash cannot be recomputed from the chain specification with Blake2 tooling from other Substrate-based chains.

Backwards Compatibility

Not applicable.

Test Cases

This is a list of manually composed examples:

# Quantus mainnet
quantus:mainnet

# Planck testnet
quantus:planck

Additional Considerations

Rejected Idea: Using the polkadot namespace

Quantus is built with the Polkadot SDK, and the polkadot namespace would have given mainnet the identifier polkadot:fb5487c0be6ae4ade2d41d16e5046512. That identifier was rejected because it would misrepresent the compatibility between Quantus and Polkadot chains. Quantus signs with ML-DSA-87 or ML-DSA-65, derives accounts by hashing the public key with Poseidon, hashes blocks with Poseidon, uses proof-of-work consensus and does not support XCM. No wallet or signer built for the polkadot namespace can produce a valid Quantus transaction.

References

• Quantus documentation - developer documentation for Quantus Network
• Quantus chain repository - node and runtime source code, including the chain specifications
• Quantus explorer - block explorer for mainnet

Copyright

Copyright and related rights waived via CC0.

Citation

Please cite this document as:

["Nikolaus Heger, "namespaces/quantus-caip2: Quantus Namespace - Chains [DRAFT]," Chain Agnostic Namespaces, quantus-caip2, September 2026 / . [Online serial]. Available: https://github.com/ChainAgnostic/namespaces/quantus-caip2.md