Kaspa Namespace - Addresses

CAIP-10

For context, see the CAIP-10 specification.

Rationale

Kaspa uses a UTXO model rather than persistent balance-bearing accounts. For CAIP-10 purposes, a Kaspa account identifier represents a native recipient or locking address.

Native Kaspa addresses use the form <prefix>:<payload>. The prefix identifies the network type, and the payload contains an address version, public key or script hash, and checksum. Because CAIP-10 does not allow : inside account_address, this profile uses the native payload without its prefix. The CAIP-2 portion already identifies the network.

Specification

A Kaspa CAIP-10 account identifier MUST follow:

kaspa:<reference>:<address_payload>

Where:

• kaspa is the namespace
• <reference> is defined by the Kaspa CAIP-2 profile
• <address_payload> is the portion after the colon in a valid native Kaspa address

The native prefix is determined by the CAIP-2 identifier:

Address Format

Kaspa defines the following address versions:

The entire address payload must match either of the following preliminary regular expressions.

For Schnorr public-key and script-hash addresses (61 characters):

^[023456789acdefghjklmnpqrstuvwxyz]{61}$

For ECDSA public-key addresses (63 characters):

^[023456789acdefghjklmnpqrstuvwxyz]{63}$

A regular-expression match is necessary but not sufficient because the decoded version, body length, and checksum must also be valid.

Resolution

To validate a Kaspa CAIP-10 identifier:

1. Validate the CAIP-2 reference according to the Kaspa CAIP-2 Profile.
2. Restore the native prefix associated with that reference.
3. Decode the reconstructed native address.
4. Validate the address version, body length, and prefix-dependent checksum.

After validation, an implementation can use Kaspa node or SDK address utilities to derive the corresponding transaction script public key. Address validity does not depend on whether the address currently has unspent outputs.

Canonicalization

Kaspa address encoders produce a canonical payload with zero-valued right-padding bits. Native decoders may accept alternative strings that differ only in unused padding bits while decoding to the same address. Implementations that compare, deduplicate, or store CAIP-10 identifiers SHOULD reconstruct the native address, decode it, and use the payload produced by re-encoding as the canonical form.

Backwards Compatibility

Not applicable.

Security Considerations

A regular-expression match alone does not establish that an address payload is valid. Implementations MUST decode the reconstructed native address and validate its version, body length, and checksum.

The native prefix MUST be derived from the CAIP-2 reference rather than accepted as separate input. The checksum binds the payload to a native prefix class such as kaspa or kaspatest, not to the complete numbered testnet reference. Implementations MUST validate the CAIP-2 reference before deriving the native prefix. A payload paired with the wrong native prefix class fails the checksum and MUST be rejected. When displaying a native Kaspa address, applications SHOULD restore and display its network prefix to avoid ambiguity.

A Kaspa address identifies a locking condition, not a persistent account, owner, or balance. Applications MUST NOT infer control of an address or the existence of spendable outputs from a valid CAIP-10 identifier.

Test Cases

Valid:

# Mainnet Schnorr public-key address
kaspa:mainnet:qp0l70zd5x85ttwd6jv7g3s3a8llzj96d8dncn4zmhv4tlzx5k2jyqh70xmfj

# Mainnet script-hash address
kaspa:mainnet:pqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqlmtfk4dg

# Testnet-10 Schnorr public-key address
kaspa:testnet-10:qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqhqrxplya

# Testnet-10 ECDSA public-key address
kaspa:testnet-10:qxaqrlzlf6wes72en3568khahq66wf27tuhfxn5nytkd8tcep2c0vrse6gdmpks

Invalid:

# Mainnet payload paired with testnet-10 (wrong native prefix class)
kaspa:testnet-10:qp0l70zd5x85ttwd6jv7g3s3a8llzj96d8dncn4zmhv4tlzx5k2jyqh70xmfj

# Native prefix incorrectly retained inside account_address
kaspa:mainnet:kaspa:qp0l70zd5x85ttwd6jv7g3s3a8llzj96d8dncn4zmhv4tlzx5k2jyqh70xmfj

# Unsupported CAIP-2 reference
kaspa:testnet-11:qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqhqrxplya

References

• Address Implementation - Native prefixes, address versions, and payload lengths
• Address Encoding - Base32 alphabet and prefix-dependent checksum
• Rusty Kaspa - Kaspa full-node implementation and related SDK libraries

Copyright

Copyright and related rights waived via CC0.

Citation

Please cite this document as:

Luke Dunshea, "namespaces/kaspa-caip10: Kaspa Namespace - Addresses [DRAFT]," Chain Agnostic Namespaces, kaspa-caip10, July 2026 / . [Online serial]. Available: https://github.com/ChainAgnostic/namespaces/kaspa-caip10.md