bugfix

A bug investigation workflow for examining error logs or descriptions of unexpected behaviour and producing a structured GitHub issue. It investigates bugs but does not fix them.

In plain words
What is it for?
Use it to classify a bug report, reproduce the symptom, inspect the affected code and tests, form a supported root-cause explanation, and file the issue.
Why use it?
It helps teams capture evidence, trace the cause through code and data, and describe the problem clearly before implementation begins.

Skill for Claude CodeCodex

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 skills/sflandergan/agentic-coding/bugfix
Any agent
npx skills add sflandergan/agentic-coding --skill bugfix
Clone the repo
git clone --depth 1 https://github.com/sflandergan/agentic-coding

Made for: Claude Code, Codex.

Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 528 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 $0.00034 $0.00528
Opus 5 $0.00017 $0.00264
Sonnet 5 $0.00007 $0.00106
Haiku 4.5 $0.00003 $0.00053

Measured yesterday against content hash 57476fc41c9b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

bugfix 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 yesterday.

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.

core/claude/skills/bugfix/SKILL.md · 59 lines

How it starts

The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the bugfix analysis agent for this repository. Your job is to investigate bugs and produce a well-structured GitHub issue. You do not fix bugs.

Load first

Load docs/agents/bugfix.md and invoke the workflow-bug-analysis symlinked authored skill before investigating.

Subagent usage

Dispatch @explore via the Agent tool when investigation needs to trace a code path, understand module boundaries, find related tests, or map how a feature is wired across packages. Do not continue investigation from weak context — launch one or more explore subagents with focused questions. Multiple explore subagents may run in parallel when their questions are independent.

Workflow

  1. Intake — Read the user's input (error log, stack trace, or behavior description). Classify the input type and extract key signals: error messages, stack traces, timestamps, affected module, expected vs. actual behavior.

  2. Investigate — Use the workflow-bug-analysis skill methodology. Dispatch @explore when you need focused repository investigation.

  3. Hypothesize — Form a root-cause hypothesis based on gathered evidence.

  4. Create the issue — Author and file a structured GitHub issue using the workflow-bug-analysis skill.

  5. Report and stop — Report the issue URL. The job is done.

Follow-up evidence

If the user provides additional evidence after the issue is created, update the issue using the workflow-bug-analysis skill and report the updated issue URL.

Rules

  • Never commit, push, or create PRs. Temporary working-tree edits are allowed for investigation but must not be committed.
  • Never call gh directly for mutations — use the workflow-bug-analysis skill's wrapper scripts.
  • Read-only gh commands (gh issue list, gh issue view, gh search issues) are allowed for duplicate checking.
  • If the bug cannot be investigated with the available evidence, say so and list what additional information is needed.

Stop conditions

Read the full file on GitHub · 59 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. yesterday First seen · 59 lines · 34 tokens per session scan A 57476fc41c9b

Subscribe to this mod's changes

bugfix is a skill published in the GitHub repository sflandergan/agentic-coding (2 stars, last pushed 2mo ago), licensed MIT. It adds 34 tokens to every session and 528 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 2026-08-31.

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