fix

A structured workflow for taking a software defect from its first report through a verified fix. A regression test is a repeatable check that proves the same bug does not return.

In plain words
What is it for?
Use it for user reports, monitoring alerts, stack traces, CI failures, and regressions that need a documented reproduction, code fix, hardening, and follow-up analysis.
Why use it?
It requires the bug to be reproduced by a failing regression specification before changing code, then reviews why existing checks missed it. This turns individual fixes into improvements to the development process.

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/swingerman/engineer/fix
Any agent
npx skills add swingerman/engineer --skill fix
Clone the repo
git clone --depth 1 https://github.com/swingerman/engineer

Made for: Claude Code, Codex.

Per session 100 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,770 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 $0.00100 $0.02770
Opus 5 $0.00050 $0.01385
Sonnet 5 $0.00020 $0.00554
Haiku 4.5 $0.00010 $0.00277

Measured 2d ago against content hash d88eb3b83351, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fix 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.

engineer/skills/fix/SKILL.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

fix

The defect unit-of-work — parallel to "feature" in the DAE pipeline. Tracks a bug from first report through a regression spec, code fix, hardening, and a structured retrospective that feeds back into the methodology.

Unlike ad-hoc fixes, the fix workflow enforces a regression spec that must be RED on current code before any change, and closes the loop with a "why didn't we catch it?" gap analysis tied to a closed category vocabulary. That loop is the methodology contribution: bugs become methodology feedback, not just patches.

When to use

  • A bug report arrives (user report, Sentry alert, stack trace, regression in CI).
  • A defect needs a repeatable reproduction path and a tracked fix.
  • A regression must be proven to stay fixed (mutation gate).

Not for: building a new capability (/engineer.discuss or /engineer.feature-init); adjusting an in-flight feature's scope (/engineer.feature-edit); reviewing recent changes without a defect (/engineer.verify or /crap-analyzer).

Workflow

Infra contract. Any step that runs tests, mutations, or the regression spec MUST first ensure required infra is up via ${CLAUDE_PLUGIN_ROOT}/scripts/dae_infra.py ensure <names> (reading the manifest's infra: section). On a start-failed failure → stop and surface the structured diagnosis. On undeclared required infra → stop with "declare in manifest" message. This applies to Steps 3, 4, 7.

Quirks contract. Before booting infra or running test commands, consult manifest.infra_quirks: apply runtime_pins (e.g. ensure JAVA_HOME matches runtime_pins.java), read port_map_file if set, surface framework_constraints to the agent if relevant ("note: Flutter web has no hot-reload — full rebuild required"), use recovery_commands keyed by failure signature when probing reports a known stuck state, and — when reproducing against a worktree whose app is mount-served — follow worktree_preview instead of rediscovering the mount switch. Quirks exist so the agent doesn't rediscover what's already documented (nexthq Java/Flutter, mmc Apache opcache).

Read the full file on GitHub · 138 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 138 lines · 100 tokens per session scan A d88eb3b83351

Subscribe to this mod's changes

fix is a skill published in the GitHub repository swingerman/engineer (144 stars, last pushed 6d ago), licensed MIT. It adds 100 tokens to every session and 2,770 once invoked, about $0.0005 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 skills, from other repositories

writing-tests

Write unit tests, component tests, and integration tests for AiderDesk using Vitest and React Testing Library. Use when creating new tests, adding test coverage, configuring mocks, setting up test files, or debugging failing tests.

hotovo/aider-desk · 48 tokens

release

Cut a sim-use release end-to-end. Use when the user runs /release or asks to "ship a release", "publish a version", "cut a release", or "release to homebrew". Drives scripts/local-release.sh; never reimplement its build/sign/tarball logic.

lycorp-jp/sim-use · 61 tokens

work-summary

Generates a project dashboard from MCP work items. Default is a lean, attention-first view: what's in flight, what's blocked, what to do next, what's queued. Use when the user says: project status, what's active, show me the dashboard, work summary, what should I work on, project health, what's blocked, where did I…

jpicklyk/task-orchestrator · 110 tokens

manage-schemas

Creates, views, edits, deletes, and validates note schemas for the MCP Task Orchestrator in .taskorchestrator/config.yaml — the templates that define which notes agents must fill at each workflow phase. Also recommends schema designs from a library of workflow patterns (autonomous coding loops, spec-driven teams…

jpicklyk/task-orchestrator · 212 tokens

bmad-dev-story

Execute story implementation following a context filled story spec file. Use when the user says "dev this story [story file]" or "implement the next story in the sprint plan".

LarsCowe/bmalph · 40 tokens

bmad-editorial-review-structure

Structural editor that proposes cuts, reorganization, and simplification while preserving comprehension. Use when user requests structural review or editorial review of structure.

LarsCowe/bmalph · 35 tokens