progress-squash

A Hermes plugin that collapses carriage-return progress bars in terminal output to the frame a terminal would show, so the model reads one line instead of every redraw.

Why

A progress bar redraws its line by writing \r and the next frame. Your terminal shows the last frame. Hermes captures the raw stream, so the model gets all of them. Measured through Hermes's own terminal tool:

Command	Output the model gets	With progress-squash
a 300-step tqdm loop	17,396 characters	about 120 characters
git clone --progress of an 11,886-object repository	18,308 characters	519 characters

The frames use up the turn's context and count against the terminal output limit (tool_output.max_bytes, 50,000 characters by default) without telling the model anything the last frame does not.

What it does

For each line of output, the \r-separated frames of the same progress line are reduced to the last one:

Receiving objects:   0% (1/11886)\rReceiving objects:   1% (119/11886)\r … \rReceiving objects: 100% (11886/11886), 67.61 MiB | 102.56 MiB/s, done.

becomes

Receiving objects: 100% (11886/11886), 67.61 MiB | 102.56 MiB/s, done.
[progress-squash: 396 overwritten progress frames removed]

Two frames belong to the same progress line when the text before their first digit or bar character matches (epoch:, Receiving objects:). Anything else written between redraws, such as an error or git's remote: Total … summary, is kept on its own line. The footer tells the model how many frames were removed. If you see it in a transcript, the plugin did the rewrite.

Left as they are:

• output with no carriage return, byte for byte (the hook returns None);
• Windows line endings (\r\n);
• a line with a single frame, or with no two consecutive frames of the same progress line.

Install

hermes plugins install progress-squash
hermes plugins enable progress-squash

Restart Hermes afterwards (CLI, gateway or desktop backend); hooks are registered when plugins load. Nothing to configure.

Where it applies

• Foreground terminal tool output: Hermes 0.21.0 and later.
• Background-process output (process_manage poll, wait and log results and completion notifications): Hermes 0.21.5 and later.

Hermes caps what it keeps of a command's output while it is still running (a head/tail window of tool_output.max_bytes) and calls this hook afterwards. Output the cap already dropped is gone before the plugin runs. The plugin saves the tokens that remain; it does not bring back the middle of a very long log.

If another plugin also registers transform_terminal_output, Hermes uses the first one that returns a string.

Security and footprint

• register() registers one hook, transform_terminal_output. No tools, commands, middleware or settings.
• No network access, no subprocesses, no files read or written, no environment variables or credentials read.
• The hook only sees the output string Hermes passes it and returns a rewritten copy. Hermes redacts secrets after the hook, so nothing the plugin returns skips redaction.
• Pure Python standard library (re), no dependencies.

Compatibility

Hermes 0.21.0 (v2026.8.31) or newer. CI runs the test suite against that release and against Hermes main every day.

Development

python -m pytest tests/test_squash.py                    # no Hermes needed
PYTHONPATH=../hermes-agent python -m pytest tests        # against a Hermes checkout

tests/fixtures/ holds real tqdm and git clone --progress output captured through Hermes's terminal tool, with its \r bytes intact. The Hermes tests install the plugin under a fresh HERMES_HOME, enable it with the CLI and run a command through the real terminal tool, with and without the plugin.

License

MIT