Pipe a file list into gnaw

gnaw reads a list of file paths from standard input and builds a prompt from exactly those files — no directory walk, no glob matching. The canonical use is handing it the output of git, so a model sees precisely what you changed:

git diff --name-only | gnaw

That pipes the names of your unstaged changes into gnaw, which sources each one, counts tokens, and renders the prompt to stdout like any other run.

Common git workflows

All of these run from the repository root, because git prints paths relative to the root and gnaw resolves them against your current directory.

# Unstaged working-tree changes
git diff --name-only | gnaw

# Staged changes only
git diff --cached --name-only | gnaw

# Everything changed since three commits back
git diff --name-only HEAD~3 | gnaw

# Changes on this branch versus main
git diff --name-only main...HEAD | gnaw

Other producers

Anything that emits one path per line works. A few that pair well:

# Every Rust file under src/ (fd)
fd -e rs . src | gnaw

# Files that mention a symbol (ripgrep -l lists matching files)
rg -l TODO | gnaw

# A hand-curated list kept in a file
cat review-set.txt | gnaw

Shaping the output

The piped list only decides which files. Everything else — format, template, destination — composes exactly as in a normal run:

# Write straight to a file
git diff --name-only | gnaw -O context.md

# Copy to the clipboard (macOS)
git diff --name-only | gnaw | pbcopy

# JSON, then inspect which files landed
git diff --name-only | gnaw -F json | jq '.files[].path'

A custom or built-in content template applies as usual with -t / --template:

git diff --name-only | gnaw -t refactor

For change review, add --diff

The git-narrative templates (write-git-commit, write-github-pull-request) render a {{git_diff}} section that a plain stdin run leaves empty — stdin supplies file contents, not a diff. To get both the changed files and the actual diff, pair the pipe with --diff so the diff chrome is loaded:

git diff --name-only | gnaw -t write-git-commit --diff

--diff reads the working-tree diff independently, so make sure it describes the same change set you piped. For per-file change views without piping, see Git diffs and logs.

What gets dropped

gnaw quietly skips paths it can't use, so a messy list is safe to pipe:

Deleted files — they appear in git diff --name-only but no longer exist on disk, so they can't be read.
Binary and empty files — dropped during extraction, same as a normal walk.
Paths outside the root — anything that resolves above your current directory is confined out, so a stray ../secrets can't escape.

Gotchas

Next steps

The Reading paths from stdin reference spells out the trigger conditions, path resolution, and how stdin interacts with filtering and templates. For folding git history into the prompt instead of just the file list, see Git diffs and logs.