coc — CMD Output Curator

AI agents consume large amounts of tokens reading CLI output. Most of it is noise — progress bars, ANSI escapes, passing tests, verbose status lines.

coc proxies CLI commands, tees their full output to a log file, and delivers curated output to stdout. When output is reduced, a footer tells you where the full logs live. Filters can be aggressive because the full output is always recoverable.

Install

From source

go install github.com/Fuabioo/coc@latest

Homebrew

brew install Fuabioo/tap/coc

Binary releases

Download from GitHub Releases.

Usage

coc [flags] <command> [args...]

Examples

coc git status          # filtered git status
coc go test ./...       # show only failures + summary
coc cargo build         # strip progress noise

coc -v git diff         # verbose mode
coc --no-filter make    # passthrough, still log
coc --no-log make       # pure passthrough
coc --version           # show version

Flags

Flag	Description
-v, --verbose	Increase verbosity
--log-dir DIR	Override log directory (default: $TMPDIR/coc)
--no-filter	Disable filtering, still write log file
--no-log	Disable log file (implies --no-filter)
-h, --help	Show help

Exit Code

Always matches the child process exit code. If the child is killed by a signal, exits with 128 + signal number.

Log Files

Full unfiltered output is written to:

$TMPDIR/coc/<command-slug>/<session-id>.log

Override with --log-dir or COC_LOG_DIR env var.

How It Works

child process
    ├── stdout → TeeReader → log file (raw, real-time)
    │                      → buffer → filter pipeline → stdout (curated)
    └── stderr → MultiWriter → log file + stderr (always unfiltered)

• Stdout is buffered, filtered, then written. The log file gets raw output in real-time via TeeReader.
• Stderr always passes through unfiltered. Errors should never be hidden.
• Footer appears on stderr only when output was actually reduced.

Limitations

• Non-interactive only: Because coc pipes stdout, isatty() returns false for the child. Commands that detect TTY will behave as if piped. This is fine for AI agent usage.
• Memory buffering: Stdout is fully buffered before filtering. Commands producing >100MB stdout may cause high memory usage.

Development

just build          # build binary
just test           # run tests (Docker-isolated)
just lint           # run linter
just install        # install to $GOPATH/bin

License

MIT