rtk-ai/rtk

Built-in filters for ssh / dig / lsof / scp (custom TOML filters don't reach the PreToolUse hook)

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#2,268 opened on Jun 4, 2026

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area:clienhancementhelp wantedpriority:high

Description

Summary

Request built-in filters for ssh, dig, lsof, and scp.

Why custom filters don't cover this

The Claude Code auto-rewrite hook (zap hook claude) only auto-prefixes commands that have a built-in filter. Commands handled only by a user-defined filters.toml are not rewritten by the hook:

$ zap hook check "ssh host docker ps"
No rewrite for: ssh host docker ps

So custom TOML filters require explicit rtk ssh ... invocation (+ zap trust) and deliver zero automatic savings through the hook. The only path to automatic interception is a built-in filter.

Evidence these are high-impact

From zap discover on a real workflow (server/infra management, 30 days):

Command Count
ssh 547 (321 + 117 + 87 + 22 across hosts)
dig +short 44
lsof 24
scp 7

ssh is the single most-used command and is entirely unhandled.

Suggested behavior

  • ssh: strip ANSI + login/locale noise (Warning: Permanently added, manpath: can't set the locale, Pseudo-terminal will not be allocated, Connection to X closed), then apply the inner command's filter when recognizable (e.g. ssh host "docker ps" → docker filter), else dedupe/cap. The remote command output is where the tokens are.
  • scp: strip transfer progress bars / ETA lines; success-only on clean transfer.
  • dig: keep answer section, drop ;; comment lines and blanks.
  • lsof: strip blank lines, cap long tabular output.

Alternative ask

If built-ins aren't desired, expose a config knob (e.g. [hooks] include_commands = ["ssh", ...]) so user TOML filters can opt into the auto-rewrite hook. Today only exclude_commands and transparent_prefixes exist.

Thanks — great tool.

Contributor guide

Tech stack
rust
Domain
clitooling
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
GitRust
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Examine how built in filters are registered in the zap hook system. Create a new module for command filters (ssh, dig, lsof, scp) that strip out common noise. For ssh, detect and apply the inner command's filter if possible. For scp, remove progress bars. For dig, keep only answer section. For lsof, cap output. Ensure they are added to the built in filter list and tested.