Free Real-Time Forex API: Live FX Data Guide免费实时外汇 API：实时行情接入指南

Forex quote sources, bid/ask meaning, and market sessions外汇报价来源、买卖价含义与交易时段

Spot foreign exchange is decentralized. A bank, broker, ECN, retail venue, central-bank reference source, and multi-provider aggregate can publish different valid rates at the same instant because their contributors, client tier, depth, executable size, and methodology differ. Every normalized record should identify the source and whether the quote is executable, indicative, midpoint, or reference data.

现货外汇没有单一集中交易所。银行、经纪商、ECN、零售交易场所、央行参考来源和多供应商聚合源，即使在同一时刻也可能给出不同但各自有效的汇率，因为它们的报价贡献方、客户层级、盘口深度、可成交规模和计算方法不同。标准化记录必须说明来源，以及该数值属于可成交报价、指示价、中间价还是参考汇率。

Define “real time” before choosing the API把“实时”要求写成可验收指标

Seconds, minutes, or streaming ticks?秒级、分钟级还是逐笔推送？

A dashboard refreshed every minute and an automated trading signal do not have the same requirement. Write down the maximum source age, acceptable network lag, required trading hours, and whether a missing update should pause the application. An API updated every 60 seconds may be real time for a currency widget but unsuitable for tick-sensitive logic.

每分钟刷新的行情看板与自动交易信号并不是同一种需求。应明确最大数据年龄、可接受网络延迟、所需交易时段，以及更新缺失时是否必须暂停应用。60 秒更新一次的接口对汇率组件可能足够实时，但不适合依赖逐笔变化的逻辑。

REST polling or forex WebSocket API?选择 REST 轮询还是外汇 WebSocket API？

REST is simpler for snapshots and controlled refresh intervals. WebSocket is better when the provider pushes frequent changes, but it adds connection state, subscriptions, heartbeat handling, reconnects, duplicate events, and sequence gaps. A WebSocket URL alone does not prove low latency; measure message timestamps and continuity.

REST 更适合快照和可控刷新；当供应商频繁推送变化时，WebSocket 更合适，但必须处理连接状态、订阅、心跳、重连、重复事件和序列缺口。仅提供 WebSocket 地址并不能证明低延迟，仍需测量消息时间戳和连续性。

Which fields must a live FX feed return?实时外汇行情必须返回哪些字段？

At minimum, require an unambiguous pair, rate type, numeric value, source timestamp, and provider or venue. Trading-oriented uses may need bid, ask, spread, and OHLC. Normalize identifiers with the ISO 4217 currency code standard, while preserving the provider’s original symbol.

至少应要求接口明确返回货币对、汇率类型、数值、来源时间戳以及供应商或交易场所。交易型场景还可能需要买价、卖价、点差和 OHLC。可依据 ISO 4217 币种代码标准统一标识，同时保留供应商原始符号。

Compare free live forex data API limits比较免费实时外汇数据 API 的限制

Free tier, trial, and keyless access are different免费层、试用与无密钥访问不是一回事

A trial expires. A free tier may continue with quotas. A keyless endpoint removes signup but can still enforce limits and usage terms. Record the plan name, verification date, monthly and per-minute limits, allowed pairs, and commercial-use rules before selecting a feed.

试用会到期；免费层可能长期存在但受额度限制；无密钥端点只是免注册，仍可能限频并受使用条款约束。选择前应记录套餐名称、核对日期、分钟/月度额度、开放货币对和商用规则。

Calculate whether the free quota is actually usable计算免费额度是否真的够用

Estimate usage before integrating: daily calls = pairs × refreshes per minute × active minutes. Five pairs polled once per minute for eight hours require 2,400 calls a day. If one request can return all five pairs, the same workflow may need only 480 calls. Check whether the provider charges by HTTP request, returned symbol, API credit, or WebSocket subscription—these models produce very different totals.

接入前先估算用量：每日调用量 = 货币对数量 × 每分钟刷新次数 × 活跃分钟数。5 个货币对每分钟轮询一次、运行 8 小时，需要 2,400 次调用；如果一次请求能够返回全部 5 个货币对，则可能只需 480 次。还要确认供应商按 HTTP 请求、返回币种、API credit 还是 WebSocket 订阅计费，因为不同模型的结果差异很大。

Test whether forex data is really real time测试外汇数据是否真正实时

Measure timestamp age and update interval测量时间戳年龄与更新间隔

Capture at least three times for every observation: the provider’s source timestamp, the moment your client receives the response or message, and the moment your system stores it. Source age equals receipt time minus source time. Observe the feed through active and quiet periods so a single fast response is not mistaken for continuous real-time delivery.

每条观测至少记录三个时间：供应商来源时间、客户端收到响应或消息的时间、系统完成存储的时间。来源年龄等于接收时间减去来源时间。应跨活跃和安静时段连续观察，不能把一次快速响应误判为持续实时传输。

Test REST and WebSocket separately分别测试 REST 与 WebSocket

# Provider-neutral verification record — not a live quote
{
  "pair": "EUR/USD",
  "rate_type": "bid_ask",
  "source_time": "SOURCE_TIMESTAMP",
  "received_time": "CLIENT_TIMESTAMP",
  "transport": "rest_or_websocket",
  "sequence": "OPTIONAL_SEQUENCE"
}

For REST, record status, rate-limit headers, source timestamp, and whether repeated requests return new observations. For WebSocket, verify authentication, subscription acknowledgement, heartbeat behavior, event order, duplicate messages, reconnect recovery, and gap detection.

REST 测试应记录状态码、限频响应头、来源时间戳，以及重复请求是否得到新观测。WebSocket 测试应验证认证、订阅确认、心跳、事件顺序、重复消息、断线恢复与缺口检测。

Reject stale, incomplete, or ambiguous quotes拒绝陈旧、不完整或含义不清的行情

Reject malformed pairs, non-positive values, timestamps outside the allowed age, and responses whose rate type cannot be identified. Do not silently convert a midpoint into bid and ask, invent a missing candle, or combine observations with inconsistent timestamps.

应拒绝格式异常的货币对、非正数、超过允许年龄的时间戳，以及无法确认汇率类型的响应。不要把中间价静默伪造成买卖价，不要补造缺失 K 线，也不要合并时间不一致的观测。

Run a repeatable acceptance test执行可重复的验收测试

1. Choose two major pairs and one less-active pair supported by the free tier.
2. Collect REST responses or WebSocket events through an active market window.
3. Record source time, receipt time, pair, rate type, bid, ask, and sequence identifier when available.
4. Calculate median and worst source age, observed update interval, duplicate rate, and missing-message count.
5. Force a disconnect or timeout, then verify backoff, resubscription, snapshot recovery, and stale-data signaling.
6. Compare the results with the written requirements and reject the feed if a mandatory condition fails.

1. 选择免费层支持的两个主要货币对和一个相对不活跃的货币对。
2. 在活跃交易时段连续采集 REST 响应或 WebSocket 事件。
3. 记录来源时间、接收时间、货币对、汇率类型、买卖价，以及可用时的序列标识。
4. 计算来源年龄中位数与最大值、实测更新间隔、重复率和消息缺失数量。
5. 主动制造断线或超时，验证退避、重新订阅、快照恢复与陈旧数据提示。
6. 将结果与书面需求逐项比较，任何强制条件失败都应淘汰该数据源。

Integrate a real time forex API safely安全接入实时外汇数据 API

Design around the free quota围绕免费额度设计刷新策略

Calculate the call budget from pairs × refreshes × clients. Centralize polling when several users need the same snapshot, cache no longer than the allowed freshness window, and slow down when rate-limit headers show the budget is nearly exhausted. For streams, subscribe only to pairs currently needed.

调用预算应按“货币对 × 刷新次数 × 客户端”计算。多个用户需要相同快照时应集中轮询；缓存时间不得超过允许的新鲜度窗口；限频响应头显示额度将尽时应主动降速。流式接口只订阅当前需要的货币对。

Handle market hours, reconnects, and gaps处理交易时段、重连与数据缺口

Forex is not continuously active every minute of the week. Distinguish a closed or quiet market from a broken feed. Use exponential backoff for transient failures, restore subscriptions after reconnect, compare sequence numbers when available, and request a REST snapshot after a detected stream gap.

外汇市场并非一周每分钟都活跃。系统必须区分休市或清淡行情与数据源故障。暂时性失败采用指数退避；重连后恢复订阅；有序列号时检查连续性；发现流式缺口后通过 REST 快照重新同步。

Keep a normalized observation record保存标准化行情记录

Store pair direction, rate type, bid, ask, midpoint or OHLC, source time, receipt time, provider, transport, and whether the value was direct or derived. This makes stale-data alerts, provider fallback, audits, and later comparisons possible without losing provenance.

应保存货币对方向、汇率类型、买价、卖价、中间价或 OHLC、来源时间、接收时间、供应商、传输方式，以及数值为直接提供还是推导得到。这样才能在保留来源链的前提下完成陈旧数据告警、供应商回退、审计和后续比较。

Set explicit go-live gates设置明确的上线门槛

If your use case also needs date-range candles or backtesting data, keep that intent separate and use the real-time market data guide. This page remains focused on selecting and operating a free live feed.

如果还需要日期区间 K 线或回测数据，应将该意图分开，并参考 实时市场数据指南。本页继续聚焦免费实时数据源的选择与运行。

Free real time forex data API questions免费实时外汇数据 API 常见问题