Add tests to existing untested code. Picks a target by risk, reads the code to understand what it actually does, matches the repo's test style, then writes characterization tests that lock in current behavior — covering happy path, edge cases, and error paths. Surfaces suspected bugs instead of silently encoding them. Standalone: does NOT touch `.plan` docs. Complements `/tdd`, which specs tests for NEW features; this covers code that already shipped without them. Use when a module has no tests, before refactoring risky code, or when hardening a legacy area. Triggers: "add tests for this", "backfill tests", "this has no tests", "cover this code", "characterization tests".
Plan and safely execute a behavior-preserving refactor. Establishes a test safety net first (runs existing tests green, adds characterization tests where coverage is thin), learns the house style, plans the change as small atomic steps, then executes step by step keeping tests green the whole way — verifying behavior never changed. Standalone: does NOT touch `.plan` docs. Use when reshaping existing code without changing what it does — reducing duplication, untangling coupling, renaming, extracting, restructuring. Triggers: "refactor this", "clean up this code", "untangle this", "extract this", "restructure this". NOT for behavior changes — that's a feature, use `/scope`.
Fast pre-commit review of your uncommitted working diff, in house style, before you commit. Reads staged + unstaged changes and new files, learns how the codebase already does things, and gives a high-signal gut-check: correctness, consistency with the codebase, obvious security/data issues, leftover debug/dead code, and missing tests — separating blocking issues from nits. Standalone: does NOT touch `.plan` docs. Distinct from `/pr-review` (whole branch vs main, with GitHub context) — this is the quick check on the working tree. Use right before committing. Triggers: "review my changes", "review the diff", "check this before I commit", "quick review", "review my working tree".
Map an unfamiliar codebase or subsystem before you touch it. Reads the repo's structure, entry points, and key paths, traces how data and control actually flow, and extracts the house conventions — then delivers an architecture map: what the major pieces are, how they fit, where to make a given change, and what looks risky. Standalone: does NOT touch `.plan` docs, but its output is the ideal warm-up before `/scope`. Use when onboarding to a new repo/job, picking up an unfamiliar area, or answering "how does this work?". Triggers: "understand this codebase", "map this repo", "how does this work", "explain this subsystem", "help me onboard".
Capture something you just learned into your Obsidian vault as a well-placed, well-written note in your own voice. Takes a spoken/typed brain-dump, figures out where it belongs in the Learn/ hierarchy, decides whether to create a new note or merge into an existing one, writes it in Nitin's note-taking voice (not AI voice), wires up wikilinks, and updates the parent index hub. Auto-detects two modes: verbatim (you dumped the full content) and expand (you gave a topic + a few points and want it written up). Use when the user says "I just learned X", "add this to my second brain", "note this down", "put this in obsidian", "capture this", or invokes /note.
Staff/principal-engineer review of a pull request. Reads the current branch's commits and diff against the main branch, pulls extra context from GitHub via `gh` (PR description, linked issues, CI, existing review threads), then reviews the change the way a senior reviewer actually does: correctness and edge cases first, then architecture, then — critically — consistency with how THIS codebase already builds things, so the code reads like the team wrote it. Standalone: does NOT touch `.plan` docs or the eng-flow pipeline. Use when the user wants a PR or branch reviewed before it lands. Triggers: "review this PR", "pr review", "review my branch", "review before I merge", "code review this".
Write a real Product Requirements Document at the bar a senior/staff engineer or PM would ship at a top org (Google, Meta, Amazon, Apple). Gathers context, grills the user on the gaps, then produces a rigorous PRD: crisp problem statement, measurable goals & explicit non-goals, success metrics with baseline→target, prioritized requirements (P0/P1/P2), user journeys, risks, dependencies, and a phased rollout. Standalone — its output can feed /scope but it is NOT in the eng doc schema. Use when the user wants a PRD, product spec, one-pager, or PR/FAQ. Triggers: "write a PRD", "product spec", "product requirements", "spec this out", "one-pager", "PR/FAQ".
Break a PRD, epic, or feature idea into well-formed user stories — "As a <persona>, I want <goal>, so that <benefit>" — each with clear, testable acceptance criteria (Gherkin given/when/then). Uses real personas when a personas skill is available, sizes stories to be independently shippable, and orders them. Output feeds /scope. Use when the user has a PRD/epic to slice or asks for user stories. Triggers: "user stories", "break into stories", "write stories for this", "slice this epic", "story map".