# `CCXT.Signing.HmacSha256Query`
[🔗](https://github.com/ZenHive/ccxt_client/blob/main/lib/ccxt/signing/hmac_sha256_query.ex#L1)

HMAC-SHA256 query string signing pattern (Binance-style).

Used by: Binance, MEXC, Huobi, and ~40 other exchanges.

## How it works

1. Add timestamp to query parameters
2. URL-encode all parameters (sorted alphabetically)
3. Sign the query string with HMAC-SHA256
4. Append signature to URL as `&signature=...`
5. API key sent in header

## Configuration

    signing: %{
      pattern: :hmac_sha256_query,
      api_key_header: "X-MBX-APIKEY",
      timestamp_key: "timestamp",
      signature_key: "signature",
      recv_window_key: "recvWindow",
      recv_window: 5000,
      signature_encoding: :hex,
      post_as_json: false
    }

Optional: set `post_as_json: true` to send POST params as JSON body
instead of query string (used by some Binance-derivative exchanges).

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*Consult [api-reference.md](api-reference.md) for complete listing*