Piped Mode

When stdin is not a terminal (i.e., input is piped), yoyo reads all of stdin as a single prompt, processes it, and exits. This works like single-prompt mode but takes input from a pipe instead of a flag.

Usage

echo "explain this code" | yoyo
cat prompt.txt | yoyo
git diff | yoyo

When to use it

Piped mode is useful for:

Passing file contents as part of the prompt
Chaining with other commands in a pipeline
Feeding structured input from scripts

Examples

Review a git diff:

git diff HEAD~1 | yoyo --system "Review this diff for bugs."

Analyze a file:

cat src/main.rs | yoyo --system "Find all potential panics in this Rust code."

Process command output:

cargo test 2>&1 | yoyo --system "Explain these test failures and suggest fixes."

Detection

yoyo detects piped mode automatically by checking if stdin is a terminal. If it is not, piped mode activates. If stdin is a terminal, interactive REPL mode starts instead.

If piped input is empty, yoyo exits with an error: No input on stdin.

Slash commands aren't dispatched in piped mode

Slash commands (/doctor, /status, /help, etc.) belong to the interactive REPL — they depend on REPL state that piped mode doesn't have. If you pipe a slash command into yoyo, it won't run it; it would only get sent to the model as a literal string and waste a turn of tokens.

Instead, yoyo detects this case, prints a one-line warning to stderr, and exits with status code 2. Use one of these alternatives: