Atomic Vaults for Centralized Exchanges
Add regulated U.S. and Hong Kong equities, ETFs, and options trading to your exchange — without becoming a broker-dealer.
Why Atomic Vaults
As a centralized exchange, you already have the user base, trading UI, and custody infrastructure. Atomic Vaults lets you expand into traditional securities with a single API integration:
- No broker-dealer license required — Atomic Vaults is your FINRA-licensed counterparty for clearing, settlement, and compliance.
- Single API, multiple markets — Access U.S. and Hong Kong markets through dedicated regional endpoints. Japan, Korea, and Taiwan coming soon.
- Full product suite — Equities, ETFs, listed options (including multi-leg strategies like spreads, straddles, and iron condors), and overnight options (US only).
- 24-hour trading — Five trading sessions (AV1–AV5) cover the full 24-hour cycle, so your users can trade U.S. securities around the clock.
- Omnibus account model — Operate under a single initiator account. Create and manage end-customer (EC) sub-accounts for each of your exchange users via API.
What You Can Offer Your Users
| Capability | US Market | HK Market |
|---|---|---|
| Equities & ETFs | Whole + fractional shares | Board-lot based |
| Listed options | Single-leg + multi-leg strategies | — |
| Overnight options (US only) | Yes (dedicated WebSocket streams) | — |
| Order types | Market, limit, stop, stop-limit | Market, limit |
| Extended hours | 24h via AV1–AV5 sessions | HK market hours (HKT) |
| Settlement | T+1 | T+2 |
Onboarding Guide
Follow these steps to integrate Atomic Vaults into your exchange platform.
Step 1: Get a staging API key
Register at the Atomic Vaults Dashboard to receive a staging API key (avs_stg_*) and test account in minutes. No sales call required for staging access.
See Self-Service Onboarding for the full walkthrough.
Step 2: Understand the account model
Atomic Vaults uses an omnibus / end-customer (EC) account structure:
Your Exchange (Initiator Account)
├── EC Account: User A
├── EC Account: User B
└── EC Account: User C
- Your exchange operates under a single initiator account with its own API key.
- Each of your users is represented by an EC sub-account, created via
POST /accounts/ec/create. - Positions and cash can be transferred between EC accounts using
/positions/ec-transferand/balances/ec-transfer.
Step 3: Set up authentication
All API requests require an X-API-KEY header. See the Authentication guide for usage, security best practices, and code examples in multiple languages.
curl -H "X-API-KEY: avs_stg_your-key-here" \
{BASE_URL}/balances
Step 4: Connect WebSocket for real-time events
Subscribe to the WebSocket channel for real-time order status updates (new, fill, partial_fill, replaced, canceled). This is essential for updating your exchange UI in real time.
See the WebSocket guide for connection setup, authentication, event types, and reconnection handling.
Step 5: Implement the trading lifecycle
The Atomic Vaults API follows a three-phase workflow:
- Pre-Trade — Onboard EC accounts, check balances and margin, fetch reference data and market status. See Pre-Trade.
- Trade Execution — Place single-leg and multi-leg orders, monitor status, modify or cancel. See Trade Execution.
- Post-Trade — Query positions, reconcile transactions, handle transfers (subaccount, EC, FOP). See Post-Trade.
See the full Trading Lifecycle overview for the end-to-end flow.
Step 6: Manage end-customer accounts
Use these endpoints to manage your exchange users:
| Action | Endpoint |
|---|---|
| Create EC account | POST /accounts/ec/create |
| List EC accounts | GET /accounts/ec |
| Update EC status | PATCH /accounts/ec/status |
| Transfer positions between ECs | POST /positions/ec-transfer |
| Transfer cash between ECs | POST /balances/ec-transfer |
See the US API Reference, HK API Reference, or KR API Reference for full request/response schemas.
Step 7: Go live
When you're ready for production:
- Complete the partner onboarding and legal agreements with Atomic Vaults.
- Set up connectivity — REST is available over the open internet with IP whitelisting; FIX connectivity requires VPN, AWS PrivateLink, or VPC peering.
- Receive your production API key and configure your environments.
Market-Specific References
- US Orders Acceptance Matrix — Order types, TIF values, and execution rules by session (AV1–AV5)
- US Risk Limits — Execution venue risk controls and order limits
- HK Market Overview — HK-specific rules, board lots, IPO support, and settlement