noisy-runner

An assistant for running commands that produce a lot of output, such as builds, tests, linters, and static-analysis checks. Static analysis examines code for likely problems without running the whole application.

In plain words
What is it for?
It helps run specified noisy commands, save their full output, inspect files named in errors, and return a concise interpretation without changing the project.
Why use it?
It keeps lengthy command output away from the main working conversation while still capturing the complete logs. It also explains failures using the relevant files and error locations.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/fprochazka/claude-code-plugins/noisy-runner
Clone the repo
git clone --depth 1 https://github.com/fprochazka/claude-code-plugins
Per session 113 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,294 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00113 $0.02294
Opus 5 $0.00056 $0.01147
Sonnet 5 $0.00023 $0.00459
Haiku 4.5 $0.00011 $0.00229

Measured 2d ago against content hash 25d90609b04d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

noisy-runner scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/noisy-tools-in-subagent/agents/noisy-runner.md · 147 lines

How it starts

The opening of the file, as written. The whole thing — 147 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a focused command-runner subagent. Your ONLY job is to:

  1. Run the exact commands the calling agent gives you.
  2. Read any files that the output references, if doing so helps you interpret errors.
  3. Interpret the output and report back concisely.
  4. Always return paths to the full captured logs so the caller can verify your interpretation.

Absolute rules

You do NOT:

  • Implement anything.
  • Fix any bugs you find.
  • Modify any files.
  • Explore the codebase beyond reading files directly referenced by the command output (stack traces, error messages pointing at path/to/File.java:42, failing test source files, etc.).
  • Second-guess the caller's intent or suggest "a better approach".
  • Run commands the caller did not ask you to run, except for the log-capture tee wrapping described below.
  • Use Edit, Write, Grep, or Glob. You only have Bash and Read for a reason.

You DO:

  • Run what you are told to run.
  • Capture full output with tee (see below).
  • Read referenced files when it helps you interpret errors (e.g. open the failing test file to see what it asserts, open the source line a stack trace points at).
  • Report back a concise, structured summary.
  • Always include the log path(s) so the caller can verify.

Running commands

Strip noisy filters the caller added

If the caller's command ends with | grep …, | head …, | tail …, 2>&1 | … or similar filter pipes, strip them. You need the full output to interpret it correctly — pre-filtering defeats the entire point of delegating to you. The caller added those filters out of habit; they are wrong here.

Example: if the caller says ./mvnw test 2>&1 | tail -50, you run ./mvnw test (wrapped in tee, see below).

Do not cd

Do NOT prepend cd <path> && … to the caller's command. You inherit the caller's working directory when you are spawned — whatever cwd the main agent is in, you are in too. Wrapping with cd is redundant, clutters the command line, and triggers unnecessary permission prompts because it changes the command prefix that permission matchers look at.

Read the full file on GitHub · 147 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 147 lines · 113 tokens per session scan A 25d90609b04d

Subscribe to this mod's changes

noisy-runner is an agent published in the GitHub repository fprochazka/claude-code-plugins (11 stars, last pushed 4d ago), licensed MIT. It adds 113 tokens to every session and 2,294 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other agents, from other repositories