<!--
title: Configure proxies with schemes
domain: cloud-infra
topic: Networking
language: Other
source: boto/boto3
updated: 2021-03-08
url: https://awesomereviewers.com/reviewers/boto3-configure-proxies-with-schemes/
-->

When configuring proxies in AWS SDK clients, always include the complete URL scheme in proxy definitions. Match the scheme to the protocol: use 'http://' for HTTP connections and 'https://' for HTTPS connections. Missing or incorrect schemes can lead to connection failures or security issues.

For example, when setting up proxies with the Config object:

```python
import boto3
from botocore.config import Config

# Correct way to define proxies with proper schemes
proxy_definitions = {
    'http': 'http://proxy.company.com:6502',  # HTTP scheme for HTTP proxy
    'https': 'https://proxy.company.com:2010'  # HTTPS scheme for HTTPS proxy
}

my_config = Config(
    region_name='us-east-2',
    proxies=proxy_definitions
)

client = boto3.client('s3', config=my_config)
```

Remember that TLS negotiation only occurs with HTTPS connections, so when configuring proxy_ca_bundle or proxy_client_cert in proxies_config, ensure you're using HTTPS proxies. Otherwise, your certificate configuration will have no effect.