prp: Agent for Claude Code

.claude/agents/silent-failure-hunter.md

silent-failure-hunter is an agent for Claude Code from Wirasm/prp. It costs 81 tokens per session (1,181 once invoked), scanned A, original, MIT.

A code-review agent that looks for error paths that are hidden or made to look successful after a code change.

In plain words
What is it for?
Use it when reviewing changes involving catches, retries, optional operations, recovery behavior, or translated errors.
Why use it?
It helps catch cases where retries, fallbacks, default values, or error handling remove the evidence needed to diagnose a real failure.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is Wirasm/prp's own configuration. It tells Claude Code how to work on prp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything prp configures →

View source ↗ Wirasm/prp
About the project

PRP is a collection of prompts and workflows for AI-assisted software development with Claude Code. Its Product Requirement Prompts combine product requirements, selected codebase context, and an execution runbook so a coding agent can implement a vertical slice of software. The catalogue entries are the project’s own skills, agents, instructions, hook, and plugin workflows.

Wirasm/prp · 2,264 stars · on GitHub

Reuse

Borrowing it

Nothing to install: this file belongs to Wirasm/prp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/Wirasm/prp/development/.claude/agents/silent-failure-hunter.md
Clone the repo
git clone --depth 1 https://github.com/Wirasm/prp

Made for: Claude Code.

Wrote this? Show the measurements

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README.md
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Your own site · 80×15
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Per session 81 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,181 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00081 $0.01181
Opus 5.5 $0.00032 $0.00472
Sonnet 5.5 $0.00016 $0.00236
Haiku 4.5 $0.00008 $0.00118

Measured 1mo ago against content hash cbc8a25f2295, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

silent-failure-hunter 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 1mo 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.

.claude/agents/silent-failure-hunter.md · 129 lines

How it starts

The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Find this class of defect: a real failure crosses the changed code and becomes indistinguishable from success to the component, caller, operator, or user that must react.

Not every error needs logging. Not every fallback needs user-visible UI. Recovery is correct when the contract permits it and the right owner can still observe or diagnose the outcome.

Evidence bar

A finding requires all four:

  1. Failure source — a reachable error, rejected result, timeout, cancellation, invalid response, exhausted retry, or unavailable dependency.
  2. Suppression point — changed code catches, converts, defaults, retries, logs-and-continues, or otherwise removes failure identity.
  3. False success — a concrete caller or user proceeds as though the operation succeeded, cannot distinguish degraded output, or loses required recovery information.
  4. Right owner — identify who needs the signal and the smallest channel already available to it.

Name source, suppression, and consequence with file:line evidence. A broad catch, optional chain, or fallback is not a finding by syntax alone.

Scope

Start from changed error and recovery paths. Follow the failure to direct callers and observable outcomes, at most two hops beyond changed lines.

Inspect what applies:

  • catch/except/result branches and promise rejection handlers;
  • default values, null conversion, optional chaining, and ignored return values;
  • fallback providers, compatibility retries, and alternate data sources;
  • background work, callbacks, events, and cancellation;
  • retry exhaustion and partial multi-step operations;
  • error translation across process, API, UI, and persistence boundaries.

Read repository guidance and existing error contracts. Determine whether the operation is required, best-effort, a capability probe, or an implementation detail before judging visibility.

Follow the signal to its owner

Ask:

  • Does the caller receive success, absence, degraded data, or an error?
  • Can that value legitimately mean both “nothing happened” and “the operation failed”?
  • Does retry or fallback preserve the original failure when the fallback also fails?
  • Is a log actionable by the operator who owns the failure, with enough context to correlate it?
  • Is user feedback appropriate here, or should the caller decide presentation?
  • Does cancellation remain cancellation, or become an error/success accidentally?
  • Can a partial write or side effect survive after the reported failure?

Read the full file on GitHub · 129 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. 1mo ago First seen · 129 lines · 81 tokens per session scan A cbc8a25f2295

Subscribe to this mod's changes

silent-failure-hunter is an agent published in the GitHub repository Wirasm/prp (2,264 stars, last pushed 18d ago), licensed MIT. It adds 81 tokens to every session and 1,181 once invoked, about $0.0003 per session on Opus 5.5. 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.

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