bugfix

A guided workflow for fixing high- or medium-priority software bugs. It uses TDD, meaning a failing test is written first, followed by the smallest fix and cleanup.

In plain words
What is it for?
It helps read an issue, plan file changes, write tests, implement a fix, run quality checks, commit the work, push a branch, and open a pull request.
Why use it?
It provides a repeatable way to fix reproducible problems while checking that the bug stays fixed. It also prepares a feature branch and pull request instead of deploying directly.

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/fall-out-bug/sdp/bugfix
Any agent
npx skills add fall-out-bug/sdp --skill bugfix
Clone the repo
git clone --depth 1 https://github.com/fall-out-bug/sdp

Made for: Claude Code, Codex.

Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 702 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 $0.00027 $0.00702
Opus 5 $0.00014 $0.00351
Sonnet 5 $0.00005 $0.00140
Haiku 4.5 $0.00003 $0.00070

Measured 2d ago against content hash 60ae8a30c851, 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 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.

prompts/skills/bugfix/SKILL.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

@bugfix

Quality bug fixes with full TDD cycle. Branch from master via feature/.

When to Use

  • P1 (HIGH) or P2 (MEDIUM) issues
  • Feature broken but not production
  • Reproducible errors

Workflow

  1. Read issuebd show <id> or load from docs/issues/
  2. Branchgit checkout master && git pull && git checkout -b fix/{id}-{slug}
  3. TDD — Red: failing test → Green: minimal fix → Refactor
  4. Quality gates — Run quality gates (see Quality Gates in AGENTS.md)
  5. Commitgit commit -m "fix(scope): description"
  6. Pushgit push -u origin fix/{branch} then gh pr create --base master

Write Plan (F101)

Before modifying any file, emit a write plan:

  1. Enumerate — List every file the skill will CREATE / MODIFY / DELETE with a one-line reason (test files and fix files).
  2. Flags:
    • --dry-run — Emit write plan only. Do NOT create, modify, or delete any file.
    • --yes — Skip confirmation prompt. Execute immediately. Intended for CI/non-interactive.
  3. Confirm — Present the plan to the user and wait for explicit approval (unless --yes).
  4. Log — Append write plan event to .sdp/log/events.jsonl (sanitize file paths before logging: strip newlines, ensure valid JSON escaping):
    {"spec_version":"v1.0","event_id":"<uuid>","timestamp":"<ISO-8601>","source":{"system":"sdp-lab","component":"bugfix"},"event_type":"decision.made","payload":{"decision_type":"write_plan","plan":[{"path":"...","action":"CREATE|MODIFY|DELETE","reason":"..."}]},"context":{"feature_id":"<F-id if known>","workstream_id":"<ws-id if applicable>"}}
    
    Include context fields only when the ID is known at plan time. Omit unavailable fields rather than inventing placeholders.

    Note: Phase 1 uses prompt-level write boundaries (CLI out of scope). Aligns with sdp/schema/contracts/orchestration-event.schema.json via event_type: "decision.made". Phase 2 CLI will emit natively.

Output format:

WRITE PLAN for @bugfix <target>:
  CREATE: path/to/new/file — <reason>
  MODIFY: path/to/existing/file — <reason>
  DELETE: path/to/removed/file — <reason>

Proceed? [y/n]

Read the full file on GitHub · 65 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 · 65 lines · 27 tokens per session scan A 60ae8a30c851

Subscribe to this mod's changes

bugfix is a skill published in the GitHub repository fall-out-bug/sdp (19 stars, last pushed 2mo ago), licensed MIT. It adds 27 tokens to every session and 702 once invoked, about $0.0001 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.