Binance (public market data)#

finance-query = { version = "...", features = ["binance"] }

Binance's public market-data endpoints need no API key. The adapter talks to data-api.binance.vision — the market-data-only host, which serves the same public endpoints as api.binance.com but carries no account or trading routes, so there is no key to configure and none to leak.

This is the first keyless source of exchange-grade crypto data in the library: CoinGecko is aggregated and coarse, and the keyed providers charge for OHLCV.

Capabilities#

use finance_query::{Capability, Interval, Provider, Providers, TimeRange};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let providers = Providers::builder()
        .route(Capability::CRYPTO, [Provider::Binance])
        .route(Capability::CHART, [Provider::Binance])
        .build()
        .await?;

    let btc = providers.crypto("bitcoin");
    let quote = btc.quote("usd").await?;
    println!("BTC {:?} ({:+.2?}%)", quote.price, quote.change_percent_24h);

    let chart = btc.chart("usd", Interval::OneHour, TimeRange::OneMonth).await?;
    println!("{} hourly candles", chart.candles.len());
    Ok(())
}

Symbols#

Binance names a market as one concatenated string with no separator (BTCUSDT). Every spelling the library uses is accepted:

CoinGecko-style coin ids are recognised for about 25 majors so a route swap between CoinGecko and Binance does not change your call sites. Anything not in that list is treated as a ticker, which is usually right.

Response Notes#

CryptoQuote:

• volume_24h is the quote-asset volume (dollars for a *USDT market), which is the figure comparable to other providers — not the base-asset volume Binance also returns.
• market_cap and circulating_supply are always None. An exchange knows what trades on it, not how much of an asset exists; route CRYPTO to CoinGecko for supply-side figures.
• name is the full coin name for the recognised majors, and the ticker otherwise.

Chart:

• Binance timestamps candles in milliseconds; they are converted to the library's seconds.
• adj_close mirrors close — crypto has no corporate actions to adjust for.
• volume is base-asset volume truncated to an integer to fit the Candle model, so sub-unit volumes round toward zero.

Intervals#

Every library interval maps to a Binance kline code except ThreeMonths, which Binance does not offer — that returns NotSupported, so sequential routing falls through to the next provider.

Binance caps a single kline response at 1000 candles. Longer windows are walked forward automatically, up to 10 requests (10,000 candles) per chart — enough for five years of daily or a year of hourly data.

Rate Limits#

Binance meters by request weight (6000 per minute per IP); the endpoints used here are weight 1–2. The client paces at 10 requests/second, well inside that. A 429 — or a 418, Binance's "you ignored a 429" ban — surfaces as FinanceError::RateLimited.

Next Steps#

• Kraken — the US-accessible sibling
• CoinGecko — aggregated market caps and supply
• Crypto Domain — the CryptoCoin handle