Ethereum Order Placement Issue: Binance API Key Format

As a developer working with cryptocurrency markets, you’re likely no stranger to the challenges of integrating with external APIs. However, when it comes to Binance’s API, a specific issue arises that can cause unexpected behavior in your Python code.

The problem is that the Binance API uses a different format for API keys than the requests library typically supports. Specifically, Binance requires an api-key parameter in the URL, which should be enclosed within double quotes (") to match the expected input format.

In this article, we’ll explore why you might encounter this error and provide workarounds using both the requests and curl libraries.

Why the api-key issue?

When you use requests or other Python libraries like curl, they typically expect a JSON-encoded string as input. Binance’s API, however, expects an api-key parameter in plain text (without quotes). This inconsistency can cause issues when trying to authenticate with the API.

The Problem: Binance Testnet API

Binance supports both testnet and mainnet APIs, but it seems that only the testnet API is affected by this issue. To confirm, try accessing the same URL on a different environment or using a different library like curl. If you’re still experiencing issues with the testnet API, we’ll focus on potential solutions.

Workaround 1: Using Binance’s API Wrapper

One solution to this problem is to use Binance’s official API wrapper for Python. This library provides an interface that allows you to make authenticated requests to the Binance API using a single api-key parameter.

import json


from binance.client import Client



Replace with your actual API key

API_KEY = "YOUR_API_KEY_HERE"

API_SECRET = "YOUR_API_SECRET_HERE"


client = Client(api_key=API_KEY, api_secret=API_SECRET)


def place_order(symbol, side, quantity, price):

    order = {

        "symbol": symbol,

        "side": side,

        "type": "limit",

        "quantity": quantity,

        "price": float(price)

    }

    result = client.placeOrder(**order)

    print(json.dumps(result, indent=4))


place_order("ETHUSDT", "buy", 10, 0.1)

In this example, we create a Client instance with your API key and secret, then define a place_order function that takes the required parameters and sends them to the Binance API using the client.placeOrder() method.

Workaround 2: Using curl with an environment variable

Another solution is to use curl with an environment variable containing your API key.

export Binance_KEY="YOUR_API_KEY_HERE"

curl -X POST \

   \

  --data-urlencode "symbol=ETHUSDT" \

  --data-urlencode "side=buy" \

  --data-urlencode "type=limit" \

  --data-urlencode "quantity=10" \

  --data-urlencode "price=0.1"

In this example, we define an environment variable BINANCE_KEY with your actual API key and secret. Then, we use the curl command to send a POST request to the Binance API with the required parameters.

Conclusion

The issue you’re experiencing is not unique to Ethereum or Binance’s APIs; it affects several other cryptocurrency platforms as well. To resolve this problem, consider using either of the workarounds outlined above.

• For requests and other Python libraries: use the Binance API wrapper library.

• For curl: set an environment variable containing your API key and secret.

By understanding why the api-key issue arises and implementing a solution, you’ll be able to successfully place orders on Binance’s testnet using Python.