Protocol
Pin the HTTP protocol version when you need to, choosing between HTTP/1.1, HTTP/2 and HTTP/3 with QUIC. Left alone, atra picks the fastest one the server supports.
Protocol Versions
Force a Specific Protocol
By default, atra automatically negotiates the best protocol. Use these flags to force a specific version.
# Force HTTP/1.1
atra GET https://api.example.com/data --http1.1
# Force HTTP/2
atra GET https://api.example.com/data --http2
# Force HTTP/3 (QUIC)
atra GET https://api.example.com/data --http3
Automatic Protocol Selection
You Do Not Have to Choose
Left alone, atra negotiates the protocol with the server and uses the fastest connection it can establish, preferring HTTP/3 where the server supports it and falling back through HTTP/2 to HTTP/1.1. There is nothing to configure and no flag to remember.
# Protocol chosen for you
atra GET https://api.example.com/data
Reach for the flags above when you need to pin a specific version, usually to reproduce a bug or to confirm a server really is serving the protocol it claims.
Certificate Info
TLS Certificate Details
Use -C / --cert-info to inspect the server's TLS certificate: subject, issuer, validity dates, key type, and algorithms.
atra GET https://api.example.com/data -C
atra GET https://api.example.com/data --cert-info
Quick Reference
Protocol Flags
| Flag | Description |
|---|---|
| --http1.1 | Force HTTP/1.1 |
| --http2 | Force HTTP/2 |
| --http3 | Force HTTP/3 (QUIC) |
| -C, --cert-info | Show TLS certificate details |