Skip to main content
The Custody API uses a two-level hierarchy to organize blockchain addresses: vault accounts contain wallets, and wallets hold assets on the Quantum Chain network.

​
Vault accounts

A vault account is a logical container that groups related wallets. Common patterns:
  • By purpose: “Treasury”, “Operations”, “Cold Storage”
  • By department: “Engineering”, “Finance”, “Trading”
  • By client: one vault per end customer in a platform model

​
Create a vault account

​
List vault accounts

​
Wallets

A wallet represents a single Quantum Chain address within a vault account. Each wallet has:
  • Address: the Quantum Chain hex address
  • Public key: the post-quantum public key associated with the address
  • Name: an optional human-readable label

​
Non-custodial registration

Since the Custody API is non-custodial, you register existing wallets rather than having the API generate keys. You provide the address, post-quantum public key, and an ownership proof from your external key management system.

​
Ownership proof

To prevent registering wallets you do not control, every registration request must include a signature over a deterministic challenge:
  1. Compute the challenge: Keccak256("qustody:register:" + lowercase_address)
  2. Sign the 32-byte challenge with your post-quantum private key
  3. Include the hex-encoded signature in the signature field
The API verifies that the public key derives to the given address and that the signature is valid.

​
Query wallet balance

​
Assets

Assets represent token types held in wallets. The Quantum Chain native token is Quantum (symbol QUANTUM); it is referenced in the API by asset_id: "QUANTUM".

​
Vault-level asset summary

Get aggregated balances across all wallets in a vault:

​
Global asset catalog

List all supported assets:

​
Hierarchy diagram

Each wallet belongs to exactly one vault account. A vault account belongs to exactly one tenant. Cross-tenant access is not permitted.