Stdin Input
Domain: CLI & Commands
Motivation
For the stdio entry modes (dsh --profile sdk, dsh --profile acp), stdin/stdout is the protocol channel: SDK clients speak JSON-RPC over stdio, and ACP clients stay connected over ACP stdio until disconnect. The one-shot headless form keeps its job in the command line instead.
Concrete Example
An SDK client pipes JSON-RPC requests into dsh --profile sdk and reads the responses on stdout.
Analogy
A walkie-talkie channel rather than a drop box: both sides stay on the line.