Capturing Command Output

Atuin can store what each command printed next to its history entry. You can then read it back in the inspector UI, search across it with atuin output search, and let Atuin AI or other AI tools read what a command actually did.

Output capture is off by default. It needs pty-proxy, which sees what your terminal displays, and the daemon, which stores it.

Setting it up

atuin config enable output-capture

This turns on the daemon (with autostart) if it isn't on already, enables pty-proxy and [output], and restarts the daemon. Open a new shell afterward.

To do the same by hand, add to your config file:

[daemon]
enabled = true
autostart = true

[pty_proxy]
enabled = true

[output]
enabled = true

If you manage the daemon yourself (systemd, launchd), restart it after changing [output]. See [pty_proxy] for other ways to start pty-proxy.

Reading captured output

In the search UI

Press Ctrl+O in search to open the inspector, pick a run, and press Enter (or O) to open its output. Colours and formatting are kept.

From the command line

atuin output search searches the output of every captured command:

atuin output search connection refused

From AI tools

• Atuin AI reads a command's output when you ask it why something failed.
• Claude Code, Cursor, and other agents can read and search it through Atuin's MCP server.

What gets captured

Atuin stores the output as your terminal displayed it at the end of the command. If you had progress bars on similar animated effects, only the "last frame" is recorded.

Some output is never stored:

• Full-screen programs such as vim, less, and htop. Anything drawn on the terminal's alternate screen is skipped.
• Commands Atuin doesn't record. Output belongs to a history entry, so a command typed with a leading space, one excluded by history_filter or cwd_filter, or a failing command with store_failed = false has none.
• Commands in command_filter. These stay in your history; only their output is dropped.
• Atuin's own credential commands: atuin key, atuin login, atuin register, and atuin account change-password.

When a command prints more than max_output_size (1MB by default), Atuin keeps the start and the end, half each, and drops the middle, recording that it's missing.

Privacy

• Recognised credentials in the output (API keys, tokens, and the like) are replaced with **** before storage, while secrets_filter is on (the default). This is best-effort: it only knows common formats, and misses a credential that colour codes split apart.
• For a command that prints secrets, don't rely on redaction: add it to command_filter to keep it in your history but never store its output. See Excluding commands.
• Captured output stays on your machine. It isn't synced, even with sync set up. We're actively working on supporting this.
• Atuin AI only sends output to the LLM when it asks for a specific command's output, and asks your permission first by default. See Reading Command Output.

Storage and retention

Output is stored on disk in the output-capture directory of Atuin's data directory (~/.local/share/atuin/output-capture by default), so it survives daemon restarts. Don't edit that directory by hand.

• Disk budget. Output may use up to max_disk_usage, 10% of the disk by default. The daemon checks about once a minute; past 95% of the budget, it deletes the oldest output until usage is back to 90%.
• Deleting history deletes output. Deleting an entry from the search UI, with atuin search --delete, atuin history prune, or atuin history dedup also deletes its output.
• Turning it off. Set [output] enabled = false. The daemon stops storing output right away; open a new shell so pty-proxy stops capturing it too. Output already stored stays on disk; to remove it, stop the daemon and delete the output-capture directory.

When changes take effect

All settings are listed in the configuration reference.