bug-hunt

bug-hunt is a skill for Claude Code, Codex from escoffier-labs/brigade. It costs 45 tokens per session (897 once invoked), scanned A, original, MIT.

A read-only code review that searches for correctness defects and reports only findings that survive attempts to disprove them. It examines logic, errors, edge cases, concurrency, and misuse of APIs.

In plain words
What is it for?
Finding bugs in reachable, important code, including wrong conditions, boundary failures, swallowed errors, race conditions, resource leaks, and broken library or project contracts.
Why use it?
Potential bugs can look convincing but be harmless or unreachable. Verification filters out weak findings so the report focuses on defects that can actually affect the software.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Good fit Finding bugs in reachable, important code, including wrong conditions, boundary failures, swallowed errors, race conditions, resource leaks, and broken library or project contracts.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/escoffier-labs/brigade/bug-hunt
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.

Any agent
npx skills add escoffier-labs/brigade --skill bug-hunt
Clone the repo
git clone --depth 1 https://github.com/escoffier-labs/brigade

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for bug-hunt

README.md
[![agentmods](https://agentmods.dev/badge/skills/escoffier-labs/brigade/bug-hunt.svg)](https://agentmods.dev/skills/escoffier-labs/brigade/bug-hunt)
Your own site
<a href="https://agentmods.dev/skills/escoffier-labs/brigade/bug-hunt"><img src="https://agentmods.dev/badge/skills/escoffier-labs/brigade/bug-hunt.svg" alt="Measured on agentmods" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 897 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Memory Poisoning · line 19
    Skill manipulates agent memory, state, or stored context. Memory corruption can alter personality, override safety rules, or cause unpredictable behavior.
    Fix: Protect agent memory and state from modification by untrusted content. Use read-only memory for critical instructions and validate all state changes.
  • medium Excessive Agency · line 71
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
How audits are shown
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 $0.00045 $0.00897
Opus 5 $0.00023 $0.00449
Sonnet 5 $0.00009 $0.00179
Haiku 4.5 $0.00005 $0.00090

Measured 8d ago against content hash c023e8d6fb93, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

bug-hunt 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 8d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • bug-hunt — 94% identical, 2 lines differ
registry/skills/bug-hunt/SKILL.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

bug-hunt

A correctness sweep that only reports bugs it failed to refute. Finders generate candidates; verifiers try to kill them; survivors make the report. The single biggest failure mode of agent bug-hunting is plausible-but-wrong findings, so verification is not optional.

Read-only. Finding bugs and fixing them are separate engagements.

Lenses

Sweep with each lens. With parallel subagents available, one finder per lens; otherwise sequential passes.

Lens Hunting for
Logic Inverted conditions, off-by-one, wrong operator, unreachable branches, broken invariants
Error handling Swallowed exceptions, missing error paths, errors that corrupt state before propagating, misleading messages
Edge cases Empty/nil/zero inputs, unicode, huge inputs, boundary values, first/last iteration
Concurrency Races, missing locks, shared mutable state, TOCTOU, async ordering assumptions
API misuse Contract violations against libraries and the project's own interfaces, ignored return values, resource leaks, lifecycle errors

Focus finders on code that is reachable and load-bearing: entry points, hot paths, recently changed files (git log --since is a good prior). A bug in dead code is info, not a finding.

Two deep lenses live as their own skills: latent-premises for unguarded assumptions that hold today with no trigger yet, and retry-safety for side effects that double-apply on a re-run. Reach for them when the sweep keeps surfacing "could break later" candidates that fail the trigger rule.

Verification (mandatory)

Every candidate gets an adversarial pass before it may appear in the report. The verifier's job is to REFUTE the finding, default skeptical:

  1. Read the actual code path end to end, including callers and guards the finder may have missed.
  2. Trace a concrete input that triggers the bug. No trigger, no bug.
  3. Check whether a test, type system, or runtime check already prevents it.
  4. Verdict: confirmed (with the triggering scenario), refuted (drop silently), or unverifiable (report downgraded one severity, marked (unverified)).

Read the full file on GitHub · 75 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. 8d ago First seen · 75 lines · 45 tokens per session scan A c023e8d6fb93

Subscribe to this mod's changes

bug-hunt is a skill published in the GitHub repository escoffier-labs/brigade (72 stars, last pushed today), licensed MIT. It adds 45 tokens to every session and 897 once invoked, about $0.0002 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.

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