Forex and Crypto Quotes API

A quotes API is the price source for the terminal, ticker, and candlestick chart. A BO or Forex platform does not invent prices: it reads a feed. REST is convenient for candle history and market snapshots; WebSocket is for ticks when polling is no longer fast enough. If the chart freezes, check the API response first, not the layout of the Buy button.

In practice an integrator has two contracts. The first is the instrument list and symbols. The second is the stream: last, bid/ask, timestamp, and sometimes volume. Without one symbol dictionary, the market table may show BTCUSDT while the terminal subscribes to BTCUSD, and both will "work" in different universes.

REST: what the response needs

The minimum candle fields are symbol, open, high, low, close, and time. For a ticker, last and change24h can be enough, but a timestamp is still required; otherwise you cannot distinguish cache from a live market. Open the endpoint in a browser or client and verify that time is fresh for the selected timeframe.

• Status codes: 200 with a body, not an empty 200 with an empty array.
• One time format: seconds or milliseconds, choose one.
• Stable field names: the client should not guess between price and last.
• Rate limits: limits without clear errors create "random" UI freezes.

For bar history, monotonic order matters: time increases and gaps are absent or clearly acceptable for Forex weekends. A gap in the middle of a crypto session is a reason to check the source, not the chart indicator.

WebSocket: ticks without extra HTTP

A socket is needed when REST polling once per second already loads both the server and browser. The client subscribes to a set of symbols, and the server pushes updates. A broken socket without UI reconnect looks like "the market stopped" even while REST history is alive. Configure reconnect and a feed status indicator in the terminal.

Do not push hundreds of pairs in one frame "just in case". Subscriptions should follow the screen: open EURUSD and listen to EURUSD. Otherwise a weak VDS and a client's phone will accumulate message queues and drop ticks. Stream details: WebSocket quotes.

1. Check hello/subscribe and confirm the frame contains a symbol and price.
2. Drop the network for a second: the UI must reconnect, not freeze silently.
3. Compare last from WS with the REST snapshot for the same symbol.

Symbols and mapping

EURUSD, EUR/USD, and EUR_USD are three different keys until you normalize them in a dictionary. The same applies to crypto: BTCUSDT from an exchange and BTC/USDT on the site card. Keep mapping in one place: the quotes script config, not scattered through templates.

If the API returns exchange tickers and the broker account area uses human names, transform them at the datafeed boundary. Otherwise TradingView Library may open an empty chart while the table is alive. Chart integration: TradingView Library, shared feed: quotes.

Access from the platform domain

A local .loc site on another machine often cannot reach the API host because of firewall rules, hosts, or whitelists. The production terminal domain must be explicitly allowed on the quotes side. CORS for browser requests is a separate check: curl from the server is green, fetch from JS is red.

HTTPS pages calling an HTTP API are blocked by the browser. A self-signed API certificate may also fail under a strict policy. For staging, one proper certificate or one reverse proxy is better than a mix of schemes.

Load and cache

Caching a public market snapshot for 1-2 seconds is reasonable. Caching a tick for BO expiration calculation for a minute is already false PnL. Separate them: the showcase can use short cache, the trading path needs a fresh stream.

Log rare API-side events: empty source, upstream failure, degradation to the last known price. In the admin area, a "feed stale" label is useful so support immediately sees why the chart is empty.

Pre-launch registration check

The integrator checklist is short and strict. Open REST history for three symbols. Subscribe over WS to one symbol and hold it for a minute. Open the terminal and verify that last on the chart and in the order book or price line do not diverge. Place a training trade and compare the entry price with the feed.

For a crypto showcase, also check capitalization and volumes if they come from the same API: CoinMarket script. Header ticker: crypto ticker. Card chart: crypto charts.

Broker connection

White-label BO and Forex consume the same API class but in different ways. Options care about price at expiration; Forex needs a continuous stream for margin and swaps. Do not replace the trading stream with a showcase cache "to save money". The saving ends with tickets about "the wrong close price".

Write client documentation in operational language: URL, headers, sample frame, symbol table, latency SLA, and escalation contacts when upstream fails. Without it, in a quarter nobody remembers why the config has three aliases for one pair.

Bottom line: a quotes API is the contract between the market and your PHP script. REST for history, WebSocket for ticks, one symbol dictionary, and domain access for the platform. When this path is green, the terminal and chart look alive; when it is red, fix the feed, not the order button. See also white label and product paths BO / Forex.

Client handover document

Attach one JSON tick example, one candle example, a symbol alias table, and the whitelist domain list to the API handover. Without this, support will guess why a new terminal subdomain cannot see the feed. State limits separately: REST requests per minute, WS subscriptions per connection, and behavior on 429.

If the exchange upstream degrades, define the policy: return last known with a stale flag or close trading. Silently substituting a stale price in the trading path is worse than a clear banner in the terminal.