No, it’s definitely curl that’s doing it.

  $ echo 'https://httpbingo.org/get?'
  https://httpbingo.org/get?
  $ python
  >>> import json
  >>> import subprocess
  >>> json.loads(subprocess.run(['curl', '-s', 'https://httpbingo.org/get?'], stdout=subprocess.PIPE).stdout)['url']
  'https://httpbingo.org/get'

I’m using curl 8.20.0-3, Arch Linux, x86_64.

  $ curl --version
  curl 8.20.0 (x86_64-pc-linux-gnu) libcurl/8.20.0 OpenSSL/3.6.2 zlib/1.3.2 brotli/1.2.0 zstd/1.5.7 libidn2/2.3.8 libpsl/0.21.5 libssh2/1.11.1 nghttp2/1.69.0 ngtcp2/1.22.1 nghttp3/1.15.0 mit-krb5/1.21.3
  Release-Date: 2026-04-29
  Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns mqtt mqtts pop3 pop3s rtsp scp sftp smtp smtps telnet tftp ws wss
  Features: alt-svc brotli GSS-API HSTS HTTP2 HTTP3 HTTPS-proxy IDN IPv6 Kerberos Largefile libz PSL SPNEGO SSL threadsafe TLS-SRP UnixSockets zstd