Introduction
Buildmarkets’s Client FIX Gateway implements FIX 4.4 protocol specifically for order management. The system delivers institutional-grade, low-latency order routing for partners preferring direct FIX connectivity alongside (or instead of) REST API integration. “FIX 4.4 — only the tags and messages documented in this section are supported.”FIX vs REST Comparison
| Factor | FIX Gateway | REST API |
|---|---|---|
| Connection | Persistent TCP session | HTTPS request/response |
| Latency | Lower (no HTTP overhead) | Standard HTTP |
| Management | Logon/Logout, heartbeats, sequencing | Bearer JWT + RSA signing |
| Order types | Equities, single/multi-leg options | Equities, single/multi-leg options |
| Best use | High-volume institutional flow, OMS/EMS | Partner portals, robo-advisory, mobile |
| Dollar/fractional | Supported (Market orders only) | Supported |
| Multileg | Native via MsgType=“AB” | Via /api/Order/CreateMultiLegOrder |
Setup Requirements
Connectivity requires: Host & Port (assigned during onboarding); SenderCompID (your identifier, Tag 49); TargetCompID (Buildmarkets’s gateway identifier, Tag 56); Heartbeat interval (30 seconds recommended, Tag 108). Contact Buildmarkets support for FIX connectivity setup.Outbound Messages
| Message | MsgType | Purpose |
|---|---|---|
| New Order Single | D | Create equity or single-leg option orders |
| New Order Multileg | AB | Create multi-leg orders (spreads, condors, straddles) |
| Order Cancel Request | F | Cancel open orders |
| Order Status Request | H | Request current order status |
Inbound Messages
| Message | MsgType | Purpose |
|---|---|---|
| Execution Report | 8 | Order acknowledgement, fills, cancellations, rejections |
| Order Cancel Reject | 9 | Cancel request rejection |
| Business Message Reject | j | Application-level message rejection |
Quick Start Process
- Establish TCP connection to assigned host and port
- Send Logon message (MsgType=“A”) with EncryptMethod=0 and HeartBtInt=60
- Await gateway Logon acknowledgement
- Send orders using MsgType=“D” (single) or MsgType=“AB” (multi-leg)
- Process Execution Reports (MsgType=“8”) for fills, updates, and rejections
- At session end, send Logout (MsgType=“5”) and await acknowledgement before closing