FIX API, REST API, and WebSocket API are three ways trading software can connect to a broker or exchange. They are not interchangeable — each is built for a different job. This page explains how they differ in connection model, latency, and order handling, and which one matters for a Forex trader using FIX API Terminal.
快速回答： A REST API uses simple request-response calls over HTTP and is good for account data and basic order placement, but it adds the most overhead per request. A WebSocket API keeps a connection open so the server can push real-time data, which suits streaming prices and live updates. A FIX API is the institutional standard for order routing and execution: a persistent, stateful session with low, consistent latency and strong recovery, and it is what Forex brokers typically expose for direct connectivity. Many platforms combine all three — FIX for execution, WebSocket for streaming, REST for account and admin tasks. FIX API Terminal connects through FIX API.
What Is a REST API?
A REST API works through individual request-response calls over HTTP. Each call is stateless: the client asks for something, the server answers, and to see new data the client has to ask again (polling). REST is simple, well documented, and common with crypto exchanges and some brokers. It is a good fit for tasks where a short delay is acceptable, such as checking a balance, pulling trade history, or placing an occasional order. The trade-off is overhead: TLS negotiation and HTTP processing add latency, typically in the tens of milliseconds, which makes REST a poor choice for real-time streaming.
What Is a WebSocket API?
A WebSocket API opens a persistent, full-duplex connection over TCP. After an initial handshake the connection stays open, so the server can push data to the client continuously without a new request each time. This removes the per-request overhead of REST and makes WebSocket well suited to streaming quotes, trade events, and live account or order updates, often across many symbols on a single connection. The cost is that a robust client must handle reconnect, resubscribe, and snapshot logic to avoid silent gaps if the connection drops. WebSocket is common in crypto trading and in the web and mobile front-ends of modern platforms.
What Is FIX API?
FIX (Financial Information eXchange) is the industry-standard protocol for order routing and execution between traders, brokers, banks, and liquidity providers. A FIX API connection is a persistent, stateful session: it uses standardized tag-value messages, tracks sequence numbers, and supports message replay and recovery, which matters when you need to prove exactly what happened to an order. When hosted close to the broker, FIX offers low and consistent execution latency. It is the protocol Forex brokers typically expose for direct connectivity, and it is what FIX API Terminal uses to trade.
FIX API 与 REST API 与 WebSocket API
| 方面 | REST API | WebSocket API | FIX API |
|---|---|---|---|
| 连接模型 | Request-response, stateless | Persistent, server push | Persistent, stateful session |
| Real-time streaming | Polling only | Yes, native | 是的 |
| Order entry and execution | Basic | Possible, less standardised | Industry standard |
| 延迟 | Highest overhead (tens of ms typical) | Lower than REST | Lowest and most consistent when well hosted |
| Recovery and audit | Per request | Needs reconnect and resubscribe design | Sequence numbers, replay, strong recovery |
| Standardisation | Vendor-specific | Vendor-specific | Standardised FIX specification |
| Typical use | Account info, history, simple orders | Streaming prices and live updates | Order routing, execution, liquidity links |
| Common in | Crypto, web and retail | Crypto, web and mobile front-ends | Institutional Forex and equities |
They Often Work Together, Not Against Each Other
In many real systems these protocols are not rivals but layers, each handling a different plane of the platform. Execution — orders, fills, and cancels, where deterministic behaviour and recoverability matter most — is handled by FIX. Streaming — prices, quotes, and trade events, where real-time delivery matters — is handled by WebSocket. Control and admin tasks — accounts, limits, reports, and configuration — are handled by REST. This hybrid pattern, FIX for execution and WebSocket for streaming with REST for the rest, has become a common way to build high-performance trading platforms.
Which Protocol Matters for a Forex Trader?
For direct Forex broker connectivity, the answer is usually FIX API. Forex brokers that offer a direct connection expose it through FIX API; REST and WebSocket APIs are more common with crypto exchanges and with the web front-ends of trading platforms. If your priority is low-latency execution, professional order types, and a direct line to the broker, FIX API is the protocol that applies.
FIX API Terminal connects to brokers through FIX API. REST and WebSocket APIs are common for crypto and for web and mobile interfaces; for direct Forex broker connectivity and execution, FIX API is what brokers provide and what FIX API Terminal uses.
Where FIX API Terminal Fits
FIX API Terminal is a Forex trading platform built around FIX API connectivity. It connects to a broker that provides a FIX API account, sends orders and receives prices and execution reports over that FIX session, and supports manual, automated, and semi-automated trading using MQL-based robots. The result is direct broker connectivity and professional execution without needing to assemble a REST and WebSocket stack yourself.
常见问题
FIX、REST 和 WebSocket API 的主要区别是什么？
REST 是通过 HTTP 进行请求-响应，最适合账户数据和简单订单。WebSocket 保持连接打开以流式传输实时数据。FIX 是一个持久的、有状态的会话，是订单路由和执行的行业标准。.
FIX API 比 REST 或 WebSocket 快吗？
当托管在靠近经纪商的地方时，FIX 通常提供最低且最一致的执行延迟。REST 每个请求的开销最大，WebSocket 则居于两者之间。它们是为了不同的工作而设计的，因此不能进行严格的同类比较。.
您可以使用 REST 或 WebSocket API 下单吗？
是的，一些 REST 和 WebSocket API 支持下单。然而，对于执行，FIX 是行业标准协议，具有更强的恢复和审计功能，这就是为什么它是机构订单路由的首选。.
哪個 API 最適合流式傳輸價格？
WebSocket 通常最适合用于流式传输价格和实时更新，因为服务器通过开放连接推送数据，而不是像 REST 那样客户端反复轮询。.
外汇经纪商使用 REST、WebSocket 还是 FIX？
For direct connectivity, Forex brokers typically expose FIX API. Some also offer REST or WebSocket endpoints, but FIX is the usual standard for low-latency order routing and execution in Forex.
Does FIX API Terminal use REST or WebSocket?
No. FIX API Terminal connects to brokers through FIX API. REST and WebSocket are common in crypto and web front-ends, but FIX API is what the platform uses for direct broker connectivity and execution.
结论
REST, WebSocket, and FIX APIs are tools for different jobs: REST for account and admin tasks, WebSocket for streaming data, and FIX for order routing and execution. For Forex trading through a broker, FIX API is the protocol that matters most, and FIX API Terminal is built to use it for direct connectivity, manual trading, and automated MQL strategies.