Production Error Hunt
different-ai/openwork
Traces an opaque production error in an OpenWork build to its cause using local server logs and Sentry, names the regressing PR and files a report.
Digs into why code is shaped the way it is by checking git history, pull requests and connected tools in parallel, then reporting a cited read on the tradeoffs.
Install Code Design Rationale Investigator
$ npx skills add cursor/plugins --skill why -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install cursor/plugins why --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/cursor/plugins.git skills-src && mkdir -p .claude/skills && cp -r skills-src/pstack/skills/why .claude/skills/why && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "why" agent skill from https://github.com/cursor/plugins/tree/main/pstack/skills/why into .claude/skills/why/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "why", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/cursor/plugins/tree/main/pstack/skills/whyType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add cursor/plugins --skill why -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install cursor/plugins why --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cursor/plugins.git skills-src && mkdir -p .agents/skills && cp -r skills-src/pstack/skills/why .agents/skills/why && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "why" agent skill from https://github.com/cursor/plugins/tree/main/pstack/skills/why into .agents/skills/why/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "why", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add cursor/plugins --skill why -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install cursor/plugins why --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cursor/plugins.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/pstack/skills/why .cursor/skills/why && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "why" agent skill from https://github.com/cursor/plugins/tree/main/pstack/skills/why into .cursor/skills/why/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "why", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/cursor/plugins.git --path pstack/skills/why--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add cursor/plugins --skill why -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install cursor/plugins why --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cursor/plugins.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/pstack/skills/why .gemini/skills/why && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "why" agent skill from https://github.com/cursor/plugins/tree/main/pstack/skills/why into .gemini/skills/why/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "why", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install cursor/plugins whyInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add cursor/plugins --skill why -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/cursor/plugins.git skills-src && mkdir -p .github/skills && cp -r skills-src/pstack/skills/why .github/skills/why && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "why" agent skill from https://github.com/cursor/plugins/tree/main/pstack/skills/why into .github/skills/why/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "why", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add cursor/plugins --skill why -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install cursor/plugins why --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/cursor/plugins.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/pstack/skills/why .opencode/skills/why && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "why" agent skill from https://github.com/cursor/plugins/tree/main/pstack/skills/why into .opencode/skills/why/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "why", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
why- GitHub stars
- 10k
- Used in
- 9 other repos
- Token cost
- ~2.6k tokens
- SKILL.md length
- 1,333 words
- Files
- 13 (incl. references)
- Skills in repo
- 99
- Repo updated
- First seen
- Licence
- None found
At a glance
Digs into why code is shaped the way it is by checking git history, pull requests and connected tools in parallel, then reporting a cited read on the tradeoffs.
- Works in 5 steps: Understand the Target and the Question → Establish the Code Anchor → Spawn Parallel Investigators (default… → …
- Asking why a function or module was built a certain way
- SKILL.md covers Operating Posture, Step 1. Understand the Target…, Step 2. Establish the Code… and Step 3. Spawn Parallel…, plus 5 more sections
- Calls git and gh
What it does
The why skill answers what forces led to a piece of code, as a companion to a separate how skill that explains what the code does. It first pins down the target and the question, makes a best guess from open files and recent edits when the request is vague, and anchors the work in file paths, key symbols, recent commits from `git blame` and pull request numbers taken from merge commits.
It then discovers which MCP servers are available and starts parallel investigators across evidence categories: source control, issue tracker, long-form docs, real-time chat, infrastructure observability, error tracking and a product analytics warehouse. The bundle has playbooks for code archaeology, incident postmortems, Databricks, Datadog, Linear, Notion, Sentry and Slack, plus prompts for the investigators and the synthesizer.
A reference on epistemics sets the confidence framework, so the final answer separates what is known from what is inferred. Subagent models are picked from role lines in a `pstack-models.mdc` rule, with defaults when the rule is missing.
When your agent uses it
- Asking why a function or module was built a certain way
- Tracing a regression back to the decision that introduced it
- Explaining a threshold or limit using the data that justified it
- Preparing a postmortem or design-history summary with cited sources
Example prompts
- “Why does the billing service retry three times before failing a charge?”
- “Look into why we moved the session cache out of the API layer and cite the PRs.”
- “Why is the upload limit set where it is? Check the issues and chat history.”
Requirements
- A Git repository with the GitHub CLI for pull request details
- MCP servers for any trackers, chat or observability tools you want searched
Workflow steps
5 steps, taken from the step headings in SKILL.md.
- Understand the Target and the Question
- Establish the Code Anchor
- Spawn Parallel Investigators (default posture)
- Synthesize
- Present
What it can do on your machine
Read from SKILL.md and the folder at commit 9f451cf. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
gitgh
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use git and gh, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Code Design Rationale Investigator loads about 2.6k tokens when it runs, and up to ~17k if it reads all its reference files. Until then it costs about 106 tokens; SKILL.md has 1,333 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Without a licence we can't republish the file, so here is its outline and opening line. It has 1,333 words (~2,591 tokens).
“Investigate the motivation and intent behind code.”
- name
- why
- disable-model-invocation
- true
Files
SKILL.md and 12 other files (references) in pstack/skills/why of cursor/plugins.
- SKILL.md
- references/epistemics.md
- references/investigator-prompt.md
- references/source-playbook.md
- references/sources/code-archaeology.md
- references/sources/databricks.md
- references/sources/datadog.md
- references/sources/incident-postmortem.md
- references/sources/linear.md
- references/sources/notion.md
- references/sources/sentry.md
- references/sources/slack.md
- references/synthesizer-prompt.md
Open the folder on GitHubat commit 9f451cf
Used in 9 other repositories
We found 9 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 9 other GitHub owners. This page covers the copy in cursor/plugins, which our catalogue first saw on October 7, 2026.
- chmonitor/chmonitor.claude/skills/pstack/upstream/skills/why
- Dimon94/skillsskills/why
- bastani-inc/atomicpackages/workflows/skills/why
- michael-denyer/pstack-claudeplugins/pstack/skills/why
- backnotprop/pstackskills/why
- tellahq/opensession.agents/skills/pstack-suite/skills/why
- am-will/gooey-pi.agents/skills/pstack/why
- jtaroreh/agystackskills/why
- uzairansaruzi/p3-stackskills/why
Compare with similar skills
Code Design Rationale Investigator next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Code Design Rationale Investigator this skillcursor/plugins | 10k | 9 repos | ~2.6k | Automated safety check: Pass | None | |
| Production Error Huntdifferent-ai/openwork | 24k | — | ~803 | Automated safety check: Pass | Custom licence | |
| Create Pull Request with Work Item IDmakeplane/plane | 60k | — | ~824 | Automated safety check: Pass | AGPL-3.0 | |
| Public Repo Guardheptameta/heptabase-cli-skills | 155 | — | ~1.2k | Automated safety check: Warn | MIT | |
| Fix Sentry Issuesbrianlovin/agent-config | 375 | 1 repos | ~1.2k | Automated safety check: Pass | None | |
| Targeted Emergency Bug FixVeryGoodOpenSource/vgv-wingspan | 108 | — | ~1.9k | Automated safety check: Pass | MIT |
Similar skills
Create Pull Request with Work Item ID
makeplane/plane
Opens a pull request for the current branch using the repo's template, a work item ID in the title and a description filled in from the actual diff.
Public Repo Guard
heptameta/heptabase-cli-skills
This repo (heptabase-cli-skills) is PUBLIC — everything committed is visible to the world and permanent in git history.
Fix Sentry Issues
brianlovin/agent-config
Use Sentry MCP to discover, triage, and fix production issues with root-cause analysis.
Targeted Emergency Bug Fix
VeryGoodOpenSource/vgv-wingspan
Applies a minimal fix to an emergency bug through triage, root-cause location, a hotfix branch and a blast-radius check, with tests and review still required.
Git Investigate
sd0xdev/sd0x-harness
Git history investigation. An agent skill from sd0xdev/sd0x-harness.
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All 99 skills in this repo- Official
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- Official
Reflect on Session Learnings
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Starts three parallel reviewer subagents over the current conversation transcript, then turns their findings into concrete edits to existing skills.
- Official
Technical Writing Standard
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Applies four layers of technical-writing rules to docs, RFCs, readmes, PR descriptions and commit messages so a tired engineer follows them on the first read.
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Advisor Mode
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Make PR Easy To Review
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Prepare PRs for review by cleaning noisy history, improving PR descriptions, and adding reviewer guidance without changing code behavior.
- Official
Build Figma
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Guides an agent through turning a Figma node into production UI with the repo's own components, then checks the result visually before finishing.
Related
Categories
Questions about Code Design Rationale Investigator
What does Code Design Rationale Investigator do?
Digs into why code is shaped the way it is by checking git history, pull requests and connected tools in parallel, then reporting a cited read on the tradeoffs. The why skill answers what forces led to a piece of code, as a companion to a separate how skill that explains what the code does. It first pins down the target and the question, makes a best guess from open files and recent edits when the request is vague, and anchors the work in file paths, key symbols, recent commits from `git blame` and pull request numbers taken from merge commits.
When should I use Code Design Rationale Investigator?
Code Design Rationale Investigator fits situations like: asking why a function or module was built a certain way; tracing a regression back to the decision that introduced it; explaining a threshold or limit using the data that justified it; preparing a postmortem or design-history summary with cited sources.
How do I install Code Design Rationale Investigator in Claude Code?
Run `npx skills add cursor/plugins --skill why -a claude-code`. Or copy the skill folder (pstack/skills/why in cursor/plugins) into .claude/skills/why in your project. Claude Code loads it when a task matches its description.
How do I install Code Design Rationale Investigator in Codex?
Run `npx skills add cursor/plugins --skill why -a codex`. Or copy the skill folder (pstack/skills/why in cursor/plugins) into .agents/skills/why in your project. Codex loads it when a task matches its description.
Can I use Code Design Rationale Investigator in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add cursor/plugins --skill why -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/why, .gemini/skills/why, .github/skills/why and .opencode/skills/why in your project.
What does Code Design Rationale Investigator need to run?
Going by SKILL.md and its folder, Code Design Rationale Investigator needs the command-line tools its instructions call (git and gh). Our summary lists: A Git repository with the GitHub CLI for pull request details; MCP servers for any trackers, chat or observability tools you want searched.
Does Code Design Rationale Investigator access the network?
SKILL.md contains no URLs. Its commands use git and gh, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Code Design Rationale Investigator safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Code Design Rationale Investigator use?
No licence was found for Code Design Rationale Investigator or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.
How many tokens does Code Design Rationale Investigator use?
About 2.6k tokens (SKILL.md is roughly 10k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 14k tokens, read only when the agent opens those files.
What are the alternatives to Code Design Rationale Investigator?
Skills that share tags, products or a category with Code Design Rationale Investigator: Production Error Hunt (different-ai/openwork, 24k stars), Create Pull Request with Work Item ID (makeplane/plane, 60k stars), Public Repo Guard (heptameta/heptabase-cli-skills, 155 stars) and Fix Sentry Issues (brianlovin/agent-config, 375 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Code Design Rationale Investigator?
cursor (a GitHub organization, an official publisher) maintains it in cursor/plugins, which has 10,130 GitHub stars. The repository holds 99 skills in this directory. The repository was last updated on October 6, 2026.
Source: cursor/plugins on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.