Creates entity model documents with Mermaid.js ER diagrams and attribute tables. Use when asked to design a database schema, create an ERD, build an entity relationship diagram, model data entities, visualize a database design, or produce a data model document with structured attribute definitions.

Configure Better Auth server and client, set up database adapters, manage sessions, add plugins, and handle environment variables. Use when users mention Better Auth, betterauth, auth.ts, or need to set up TypeScript authentication with email/password, OAuth, or plugin configuration.

Creates Nx plugins, builds custom generators, configures inferred tasks, and writes version migrations for Nx workspaces. Use when the user wants to create a custom Nx plugin, scaffold a generator with nx generate, add inferred tasks, write workspace migrations, build a custom executor, develop a plugin preset, or extend an Nx workspace with custom tooling. Covers nx plugin development, generator templates, Nx Devkit API usage, schema definitions, testing generators, and publishing plugins.

Author high-quality Markdown documentation with deterministic structure, lint compliance, and CI integration. Use when writing README files, creating docs pages, fixing markdownlint failures, defining style rules, or wiring markdown checks into pre-commit and pipelines. Keywords: markdown, markdownlint, readme, docs, headings, lists, code fences, links, images, lint config, ci, documentation style.

Comprehensive toolkit for validating, linting, testing, and automating Terraform configurations and HCL files. Use this skill when working with Terraform files (.tf, .tfvars), validating infrastructure-as-code, debugging Terraform configurations, performing dry-run testing with terraform plan, or working with custom providers and modules.

Generate PromQL queries for calculating error rates, aggregating metrics across labels, creating histogram percentiles, writing recording rules, and building SLO burn-rate alerts following Prometheus best practices. Use when creating new PromQL queries, implementing monitoring and alerting rules, building observability dashboards, working with Prometheus metrics (counters, gauges, histograms, summaries), or applying RED (Rate, Errors, Duration) and USE (Utilization, Saturation, Errors) monitoring patterns.

Comprehensive toolkit for validating, linting, and optimizing Makefiles. Use when working with Makefiles (Makefile, makefile, *.mk files), validating build configurations, checking for best practices, identifying security issues, or debugging Makefile problems. Concrete capabilities include detecting missing .PHONY declarations, validating tab indentation in recipes, checking variable expansion safety, identifying hardcoded credentials, and flagging missing prerequisites or syntax errors.

Integrate Biome into Nx monorepos with deterministic setup, caching, migration from ESLint and Prettier, and plugin-based inferred tasks; use when adding Biome, replacing ESLint/Prettier, tuning cache inputs, or scaling lint and format workflows across projects.

Inspect pod logs, analyze resource quotas, trace network policies, check deployment rollout status, and run cluster health checks for Kubernetes. Use this skill when diagnosing Kubernetes cluster issues, debugging failing pods, investigating network connectivity problems, analyzing resource usage, troubleshooting deployments, or performing cluster health checks.

Validates .gitlab-ci.yml syntax, detects security misconfigurations in job definitions, checks for deprecated keywords, ensures proper stage ordering, and audits pipeline configurations for best practices. Use when working with .gitlab-ci.yml files, validating GitLab CI/CD pipeline syntax, debugging configuration errors, checking for hardcoded secrets or credentials in pipeline jobs, optimizing pipeline performance with DAG or cache, or performing security audits on GitLab CI/CD configurations.

Generates production-ready GitHub Actions workflows, custom actions, and CI/CD configurations following security and performance standards. Creates CI/CD pipelines, test workflows, deployment configurations, matrix builds, caching strategies, composite actions, Docker actions, JavaScript actions, and reusable workflows. Use when creating or scaffolding GHA resources, writing .github/workflows YAML files, setting up build automation, implementing deployment pipelines, adding security scanning, or building reusable actions — including triggers like 'create a workflow', 'build a pipeline', 'add CI', 'set up GHA', or 'generate a YAML workflow'.

Comprehensive toolkit for validating, linting, testing, and automating Ansible playbooks, roles, and collections. Use this skill when working with Ansible files (.yml, .yaml playbooks, roles, inventories), validating automation code, debugging playbook execution, performing dry-run testing with check mode, or working with custom modules and collections.

Enforce AWS CDK security and compliance controls with cdk-nag. Use when adding rule packs, triaging findings, writing justified suppressions, integrating checks in CI/CD, or preventing insecure infrastructure patterns in CDK stacks.

Creates test stacks, analyzes CloudFormation events, and compares actual vs documented update behavior to validate whether resource property changes trigger replacement or in-place updates. Use when: a user wants to test if a CFN property change causes resource replacement; when investigating stack update behavior or "Update requires" documentation accuracy; when validating whether a workaround (e.g. hash-based logical IDs) is actually necessary; when questioning UpdateRequiresReplacement behavior for immutable properties; when empirical evidence is needed before an architectural decision involving CDK or CloudFormation stack updates.

Iteratively review and optimize Tessl skills using `tessl skill review` — validates frontmatter, checks description specificity and trigger terms, evaluates content conciseness, actionability, and workflow clarity, then applies automated optimizations and re-reviews until quality targets are met. Use when the user wants to evaluate, improve, or optimize skills in their project — e.g. "review my skills", "optimize my skills", "improve skill quality", "run tessl review", or "make my skills better". Also use when the user wants to demonstrate the value of Tessl skill review.

Collect and document UX feedback when using tools as an AI agent. Records unclear interactions, unexpected outcomes, and pleasant experiences. Use when the user asks for: bug report, feature request, usability feedback, tool improvement suggestions, or "what do you think about this tool".