Introduction
Introduction
The ACY Connect FIX API provides institutional and professional traders with a robust, low-latency gateway to access ACY's trading infrastructure.
It supports high-performance trading and quoting through FIX 4.4, incorporating selected FIX 5.0 SP2 (EP284) extensions to meet enhanced regulatory and operational requirements.
1. Connectivity Overview
Before establishing a FIX 4.4 connection, ensure the client's source IP is whitelisted on the ACY Connect firewall.
Connection Steps:
- Socket Setup – The client opens a TCP socket to the designated FIX API port.
- Logon – Client initiates with a FIX Logon message (
35=A). - Acknowledgement – ACY Connect responds with a Logon (
35=A) confirming the session. - Heartbeat Maintenance – Both sides exchange Heartbeat messages (
35=0) periodically to maintain connection stability.
This process secures the link via firewall protection, ensuring a stable channel for quoting and trading activities.
2. Credentials and Verification
Each client receives dedicated credentials for both Quote and Trade sessions, configured in the FIX engine:
| Parameter | Description |
|---|---|
| IP Address | Endpoint provided by ACY Connect |
| Port | FIX listening port |
| SenderCompID | Client's unique identifier |
| TargetCompID | ACY Connect's unique identifier |
| Password | Session password provided by ACY Connect |
Verification Command:
telnet <IP Address> <Port>A blank screen means the connection is successful. Contact ACY Connect Support if the test fails.
3. FIX Protocol and Usage Notes
The API follows FIX 4.4 conventions with FIX 5.0 SP2 extensions.
ACY Connect may introduce custom fields (prefixed ACY) for reporting or operational needs.
Message Field Requirements:
- Y = Required
- N = Optional
- C = Conditional (as noted)
Other Notes:
- Fields are grouped into Header, Body, and Trailer.
- The first field in any repeating group must remain fixed.
- Clients must send Heartbeat (
35=0) at least every 30 seconds. - Timestamps follow UTC format:
YYYYMMDD-HH:MM:SS.sssor.ssssss.
4. Session Messages
Session-level messages manage connection setup, maintenance, and logout.
Supported administrative messages include:
| Message Type | Description |
|---|---|
| Logon (35=A) | Start session |
| Heartbeat (35=0) | Maintain connection |
| Test Request (35=1) | Verify session state |
| Resend Request (35=2) | Request missed messages |
| Reject (35=3) | Invalid message format |
| Logout (35=5) | Terminate session |
5. Application Messages
Application messages handle trading and market data operations.
Trading Messages:
- NewOrderSingle (35=D) – Submit new order
- ExecutionReport (35=8) – Report execution results
- Order Cancel Request (35=F) – Request to cancel order
- Order Cancel Reject (35=9) – Cancel request rejected
Quoting Messages:
- MarketDataRequest (35=V) – Subscribe to market data
- MarketDataRequestReject (35=Y) – Market data request failed
- MarketDataSnapshot / Full Refresh (35=W) – Market data update
- Quote Cancel (35=Z) – Cancel quote subscription
6. Reject Scenarios
Rejections can occur at both session and business levels:
| Type | Description |
|---|---|
| Execution Report Reject | Order request fails validation |
| Session Reject Message | Invalid tag or field order |
| Business Message Reject | Violates trading logic |
| Market Data Reject | Malformed or unauthorized request |
Summary
The ACY Connect FIX API delivers a secure, standards-compliant interface for institutional trading and market data.
By adhering to FIX 4.4 conventions and maintaining strict session control, it ensures stability, performance, and compatibility for professional trading systems.