Use CAIP-2 network identifiers

[andreabadesso]

Current behavior

We use informal network strings like hathor:privatenet, hathor:testnet, hathor:mainnet. These are close to CAIP-2 but not formally registered.

Required behavior

The x402 V2 spec uses CAIP-2 chain identifiers. For EVM chains this is eip155:<chainId>, for Solana solana:<genesisHash>.

Hathor needs a CAIP-2 namespace. The format should be:

hathor:mainnet
hathor:testnet
hathor:privatenet

This is already what we use, but it needs to be:

1. Formally documented as Hathor's CAIP-2 namespace
2. Registered with ChainAgnostic/namespaces
3. Used consistently across all protocol messages

Changes needed

All files

• Audit all hardcoded network strings and ensure they follow hathor:<network> format consistently
• The config.network value should be used everywhere instead of hardcoded strings

External

• Submit a PR to ChainAgnostic/namespaces to register the hathor namespace
• Document the namespace in our RFC (0001)

Current network strings in code

The resource server has hathor:${config.network} in some places, which is correct. The facilitator has some hardcoded hathor:privatenet strings that need to use config.

References

• CAIP-2 Specification
• x402 Network Support