Derives human-readable manual test cases from a business-rule spec via a decision table: identify conditions and actions, build the full 2^n-column matrix, collapse columns with irrelevant entries, strike infeasible combinations, then emit one test case per remaining column (each feasible column is one coverage item per ISTQB CTFL v4.0 section 4.2.3). A deep single-technique walkthrough rather than a broad multi-lens case matrix; the output is manual step/expected cases rather than parameterized test code, and it covers how cases are derived rather than how a case record is structured. Use when a spec's outcome depends on interacting conditions (pricing, eligibility, discounts, routing rules) rather than the boundaries of a single input.

Build-an-X workflow that verifies locale-specific format rendering - dates (US `5/4/2026` vs ISO `2026-05-04` vs DE `04.05.2026` vs JP `2026/05/04`), numbers (US `1,234.56` vs DE `1.234,56` vs FR `1 234,56`), currencies (US `$1,234.56` vs JP `¥1,235` vs DE `1.234,56 €`), times, durations. Use when the product displays locale-sensitive data and the team needs assurance the formatting matches per-locale conventions.

Reference catalog of data-quality conventions - when to choose dbt-tests vs Great Expectations vs Soda, column-level vs table-level coverage, severity tiering, SLA and freshness conventions, and common anti-patterns to avoid. Use when designing coverage for a new data product or auditing an existing one.

Diffs two GraphQL schemas with `graphql-inspector diff`, classifies each change as BREAKING / DANGEROUS / NON_BREAKING, and applies opt-in rules (suppress-removal-of-deprecated-field, consider-usage, ignore-description-changes) to gate CI on schema regressions. Use when reviewing GraphQL schema changes in a PR or evaluating Federation supergraph drift.

Snapshot testing for terminal UI apps (TUIs) - captures rendered terminal frames as deterministic SVG / text snapshots, diffs them on every run, surfaces a reviewable HTML report on failure, and supports `--snapshot-update` to accept changes intentionally. Wraps `pytest-textual-snapshot` for Python Textual apps; provides equivalent recipes for Ratatui (Rust) `insta` snapshots, Charm Bracelet (Go) `teatest` golden files, and Ink (Node) `ink-testing-library`. Use for any TUI where layout regressions otherwise reach users via `screenshot looks wrong in terminal`.

Build-an-X workflow for a chaos experiment per the Principles of Chaos Engineering - defines steady-state hypothesis, picks the variables (real-world events: network latency, node failure, region outage), sets the blast radius (which percentage / namespace / user cohort), automates execution, and emits the verdict (steady-state held / didn't hold). Includes the five-check pre-flight validation of the steady-state hypothesis (measurable, baselined, SLI-backed tolerance, defined measurement window, metric moves under the fault) with hard-reject rules, and routes the tool choice: Chaos Mesh has its own standalone skill, while LitmusChaos and Gremlin setup live in this skill's references. Use to scope and pre-flight-validate a chaos experiment before running it via Chaos Mesh / Litmus / Gremlin / Toxiproxy.

Authors WebdriverIO E2E tests - `npm init wdio@latest` scaffolding, services architecture (sauce, browserstack, appium, devtools), reporters (spec, allure, junit), built-in Mocha/Jasmine/Cucumber framework integrations. WebdriverIO sits between Selenium (W3C protocol) and Playwright (modern API) - Selenium-protocol-compatible with rich plugin ecosystem. Use when the team needs WebDriver protocol + service-based device-farm integration.

Use when swizzling Docusaurus theme components and editing theme elements — wrap or eject components from @docusaurus/theme-classic, override navbar/footer/sidebar/TOC/DocItem, place customised components under src/theme/, and choose safe (--wrap) vs full (--eject) swizzles. Triggers on tasks involving Docusaurus swizzling, theme component customization, navbar, footer, sidebar, or layout modifications.

Use when working with docusaurus.config.js/ts files — validate the config structure, set required fields (title/url/baseUrl), fix URL and baseUrl formats, add presets and plugins, configure navbar/footer/theme settings, and move unknown keys into customFields. Triggers on tasks involving docusaurus.config.js, docusaurus.config.ts, site configuration, URL formats, presets, or theme config.

Use when troubleshooting, implementing, reviewing, or auditing platform infrastructure as a system — where Kubernetes, GitOps, CI/CD, and security concerns intersect. Provides structured diagnosis with blast radius, validation steps, and rollback plan for: Kubernetes, Flux CD, Argo CD, Terraform, GitHub Actions (composite actions, OIDC, SHA pinning), AWS, Azure, GKE, Linkerd, KEDA, Karpenter, supply chain security (Cosign, SBOM, SLSA), Falco, Chaos Engineering, DORA metrics, Datadog/Dynatrace/LLM observability, SOC 2, and PR review.

Execute Jira or Confluence operations given an Atlassian URL and task instructions. Use when the user wants to create, read, update, delete, or search Jira/Confluence resources and needs endpoint discovery, payload construction, and authenticated API execution. Trigger on any request mentioning Jira, Confluence, Atlassian, tickets, epics, sprints, backlogs, wiki pages, or related Atlassian workflows.

Adds hard similarity threshold guards to vector retrieval RPCs. Returns empty results instead of weak matches to prevent downstream hallucination. Use when implementing retrieval guardrails, minimum similarity thresholds, match_threshold parameters, or preventing RAG hallucination from low-confidence results.

Configures private Realtime channels with RLS-backed authorization on the realtime.messages table. Enforces tenant-scoped Presence and Broadcast security. Use when implementing private realtime channels, realtime authorization, presence security, broadcast security, or securing the realtime messages table.

Sets up Prometheus scrape jobs targeting the Supabase metrics endpoint and configures log drain pipelines. Establishes monitoring dashboards and alerting baselines. Use when configuring Supabase monitoring, setting up Prometheus metrics, implementing log drains, or establishing observability for production Supabase deployments.

Creates Postgres triggers that fire database webhooks to Edge Functions or external endpoints on INSERT/UPDATE/DELETE events. Configures pg_net for HTTP callouts and payload serialization. Use when implementing event-driven workflows, database webhooks, trigger-based notifications, or automated pipelines on table changes.

Configures Edge Functions to use EdgeRuntime.waitUntil for background work while returning immediate 200 OK. Routes massive async workloads through pg_cron discovery and pgmq task queuing. Use when building background processing, async third-party calls, long-running edge function tasks, or webhook-driven pipelines.

Creates Postgres functions to validate storage path payloads and prevent directory traversal. Enforces tenant-safe file paths via storage RLS bucket policies. Use when configuring Supabase storage buckets, writing storage RLS policies, or implementing tenant-scoped file uploads.

Enforces that service_role key is never exposed to client-side code. Validates admin client isolation, privileged operations routing, and server-only key usage. Use when implementing admin operations, server-side Supabase clients, or auditing service_role key usage.

Generates Postgres Auth Hook that injects tenant_id and serialized permissions into JWT app_metadata using jsonb_set. Use when implementing RBAC, multi-tenant JWT claims, custom access token hooks, or permission injection into Supabase auth tokens.

Writes and executes JavaScript-based shell scripts using Google's zx library. Use when writing shell scripts, automation, build tools, file processing, CLI tools, deployment scripts, data pipelines, or batch operations. Also covers piping, streams, parallel execution, retries, cross-platform scripting, built-in fs utilities, and minimist argument parsing.