Aleo Network - Namespace Chains

Author Jonathan Gonzalez,
Status Draft
Type Standard
Created 2023-09-12


For context, see the CAIP-2 specification.


The namespace aleo refers to the Aleo Network Layer 1 blockchain.

To date, Aleo consists of a single network: a testnet network (Testnet3).

An identifier for a Aleo chain consists of the namespace prefix “aleo:” followed by the chain id.


The Aleo chain ID system maps between a human-readabe string (used to discriminate networks in the paths of node endpoints, for example) and an unsigned 16-bit binary integer, known colloquially as an “u16 number”, ranging from 0 to 65535 which is used internally. For example, at time or writing, the u16 number 3 maps to testnet3 and 0 will map to mainnet once the latter has been released. The canonical location of the mapping of u16 integers to network name strings is still to be determined by the community, but in the case of conflicts between the community documentation and this document, the former should be taken as canonical.

Backwards Compatibility


Resolution Method

To resolve a reference for the Aleo namespace, get the latest block information from the chain you are interested in from an Aleo API node. An example using Javascript:

  .then(response => response.json())
  .then(response => console.log(

will log 3.

Test Cases

This is a manually composed example.

# Aleo Testnet3

# Aleo mainnet

Additional Considerations (*OPTIONAL)

Mainnet will release sometime Q1 2024. The API is subject to change and the example above (particularly other properties) may become inaccurate over time.


Copyright and related rights waived via CC0.


Please cite this document as:

Jonathan Gonzalez,, "namespaces/aleo-caip2: Aleo Network - Namespace Chains [DRAFT]," Chain Agnostic Namespaces, aleo-caip2, September 2023 / . [Online serial]. Available: