A FIX API is a connection to a broker, bank or exchange that uses the FIX (Financial Information eXchange) protocol to send orders and receive market data directly, without a retail platform such as MetaTrader in between. FIX is an open messaging standard maintained by the non-profit FIX Trading Community. In retail and institutional Forex, most providers use FIX version 4.4. A FIX API usually gives lower and more predictable latency than a platform connection, but it needs a FIX engine or trading software that supports FIX, and brokers often require a minimum account size to enable it.
How FIX API works in Forex trading
Your software (the client) and the broker’s FIX server open a session over TCP, usually with SSL. Every message is a list of numbered tag=value fields. Tag 35 (MsgType) defines what the message is. Most providers run two separate sessions:
- Market data (price) session: streams quotes and order-book updates for the symbols you subscribe to.
- Trading (order) session: sends orders and returns execution reports, fills, rejections and position updates.
- Session identity: each session uses its own host, port, SenderCompID, TargetCompID and credentials, issued by the provider.
- Sequence numbers: every message is numbered (tag 34). If a message is lost, the side that notices requests a resend, so both systems stay in sync.
Main FIX 4.4 message types
| MsgType (tag 35) | Message | What it does |
|---|---|---|
| A | Logon | Opens the session and sets the heartbeat interval |
| 0 | Heartbeat | Keeps the session alive when no other messages are sent |
| V | Market Data Request | Subscribes to quotes for a symbol |
| W / X | Market Data Snapshot / Incremental Refresh | Delivers prices: a full snapshot or only the changes |
| D | New Order Single | Sends a new order: symbol, side, quantity, order type |
| F | Order Cancel Request | Cancels a working order |
| 8 | Execution Report | Reports order status: accepted, partially filled, filled, rejected |
| 3 | Reject | Rejects a message that breaks session rules |
| 5 | Logout | Closes the session |
The exact list depends on the provider. Always read its FIX specification: supported order types, time-in-force values and custom tags differ from venue to venue.
FIX API vs MetaTrader vs REST/WebSocket API
| Parameter | FIX API | MT4/MT5 platform | REST / WebSocket API |
|---|---|---|---|
| Connection | Direct session to the broker’s FIX server | Through the broker’s MetaTrader server | HTTP requests and streaming over the web |
| Latency | Lowest and most stable of the three | Adds the platform server layer | Usually higher; depends on implementation |
| Who uses it | Banks, funds, prop traders, algo traders | Most retail traders | Crypto exchanges, retail brokers, developers |
| Setup | FIX engine or software with FIX support | Install the terminal | Any programming language |
| Access | Often requires approval or a minimum deposit | Available on any account | Usually free with an API key |
Advantages and limitations of FIX API
- Speed: fewer layers between your strategy and the liquidity, which reduces execution latency.
- Transparency: execution reports show each state of the order with timestamps, which helps you measure slippage, requotes and rejections.
- Standard protocol: one FIX engine can connect to many brokers and venues with small changes.
- Limitation, access: many brokers enable FIX only for professional or high-balance accounts.
- Limitation, complexity: session handling, sequence resets and reconnects must be managed correctly, or orders can be lost or duplicated.
- Limitation, no built-in protection: FIX sends what your software tells it to send. Risk limits must be set in your software and on the broker side.
How to get FIX API access from a broker
- Check availability: ask whether FIX is offered for your account type and what the minimum deposit or volume is.
- Request the specification: FIX version (usually 4.4), supported messages, order types and custom tags.
- Get demo credentials: most providers give a test (UAT) environment first. Test logon, quotes, orders, cancels and reconnects there.
- Whitelist your IP: many FIX servers accept connections only from registered IP addresses, so use a VPS with a static IP.
- Move to live: the provider issues production hosts, ports and CompIDs after testing.
Regulatory view
FIX is a technical standard, not a regulated product, but trading through it is covered by the same rules as any other channel. In the EU and UK, firms that execute client orders must meet MiFID II and FCA best-execution requirements whatever the connection type. Firms offering direct electronic access must also have pre-trade risk controls and monitoring in place under MiFID II rules on algorithmic trading, which ESMA and national regulators supervise. For you, this means a FIX connection to a regulated broker still comes with order limits, credit checks and the broker’s execution policy.
FIX API in Westernpips Private 7
For latency arbitrage, FIX is used on both sides: to receive a fast price feed from a liquidity provider or exchange, and to send orders to a broker without the delay of a platform terminal. Westernpips Private 7 includes ready-made FIX connectors, for example LMAX FIX, cTrader FIX and Dukascopy FIX, plus API connectors for crypto exchanges such as Binance. See the full list of connectors, the FIX connection settings and how to read FIX logs. If a broker offers only MetaTrader, the MT EA connector is used instead.
FAQ about FIX API
Is FIX API free?
The protocol is open and free to use. Access to a broker’s FIX server may require a minimum deposit, monthly volume or a fee, depending on the provider.
Which FIX version is used in Forex?
FIX 4.4 is the most common in Forex and CFD trading. Some venues use 4.2 or 5.0 SP2; the provider’s specification states which one.
Can I trade crypto through FIX API?
Yes, several large crypto exchanges offer FIX alongside their REST and WebSocket APIs, usually for institutional or high-volume accounts.
Do I need to program to use FIX API?
Not necessarily. You can write your own FIX client, or use trading software that already includes FIX connectors and only needs the credentials from your broker.
Risk warning: Leveraged trading in Forex, CFDs and crypto assets can result in losses that exceed your initial expectations. Connection speed does not remove market risk, slippage or broker-side restrictions. This article is for educational purposes only and is not investment advice.