mastra

Universal quality bar and final audit rubric for any agent system prompt. Activate this whenever you are unsure which archetype skill applies, or as a final review pass before writing the system prompt. It defines the required run contract, completion criteria, fallback paths, response format, and anti-patterns every produced agent prompt must satisfy.

Smoke test the Agent Builder feature branch end-to-end against a hermetic project scaffolded by the skill (linked to the current worktree). Covers workspace reconciliation, stored agents/skills CRUD, ownership, visibility, stars, registry/library Copy flow, picker allowlists, model policy, RBAC role gating, role impersonation UI, builder defaults, infrastructure diagnostics, channels, and Studio + Agent Builder UI. Trigger when validating the agent-builder feature branch, PRs that touch packages/server, packages/playground, packages/playground-ui agent-builder routes, or builder EE code paths.

Code quality standards and style guide for reviewing pull requests

Authoring playbook for building agents that write, edit, review, or refactor code. Use this when the user asks for an agent that writes scripts, generates code, reviews pull requests, refactors a codebase, fixes bugs, implements features, writes tests, or works with programming languages such as Python, TypeScript, JavaScript, Go, Rust, SQL, or shell.

Configure board-owned lifecycle, policy, phase-semantics, and tool-result rules, plus integration event rules

Authoring playbook for building agents that draft written content — blog posts, marketing copy, social media posts, newsletters, product descriptions, landing pages, or ad copy. Use this when the user wants an agent that writes, drafts, or rewrites text for publication or marketing.

Authoring playbook for building agents that triage and reply to customer messages — support tickets, email inquiries, chat questions, refund requests, or product issues. Use this when the user wants an agent that handles inbound customer questions, drafts replies, escalates hard cases, summarizes tickets, or follows a support playbook.

Use early when debugging a medium or hard bug, especially when tests alone may not reveal the real runtime failure. Trigger this before extended TDD iteration when a bug involves runtime state, ordering, persistence, streaming, concurrency, UI/manual reproduction, external services, or when a red or newly passing test may not model the real issue. Skip only when the root cause is already directly proven by a stack trace or deterministic test that exercises the real runtime path.

Autonomous, report-only documentation review for Mastra docs. Use when auditing changed docs against source, validating contextual code examples or API coverage, checking canonical mastra-docs guidance, or running narrow deterministic checks.

Convert existing docs diagram images to Mermaid, and author new Mermaid diagrams for Mastra docs. Use when replacing an Excalidraw or PNG/JPG/SVG diagram with Mermaid, when a docs page needs a new diagram, when a diagram renders wrong in light or dark mode, or when auditing which docs images should become Mermaid. Triggers on: convert diagram, Excalidraw, mermaid, flowchart, diagram image, diagram styling, diagram looks wrong.

REQUIRED when modifying any file in packages/playground-ui or packages/playground. Triggers on: React component creation/modification/refactoring, UI changes, new playground features, bug fixes affecting studio UI. Generates Playwright E2E tests that validate PRODUCT BEHAVIOR, not just UI states.

Mark a GitHub issue as done and update its status labels

Re-review a GitLab merge request after new commits and reconcile the previous review

Review a GitLab merge request for a Factory work item using brokered source-control tools

Produce a phased implementation plan for a Factory work item, then advance it to execute

Re-review a pull request after a push — reconcile the previous review against the new commits, look for new defects the push introduced, then a fresh pass over the whole PR, and finish with a verdict on the PR

Review a pull request for a Factory work item — history and context first, then a verdict published on the PR — and mark the review complete

Review and test a Factory work item's pushed branch before any pull or merge request exists, then record the verdict that sends it back to Building or on to open the change request

Triage a Factory work item's issue — trace history, understand architecture, diagnose root cause, then advance the stage

Helps users discover and install agent skills when they ask questions like "how do I do X", "find a skill for X", "is there a skill that can...", or express interest in extending capabilities. This skill should be used when the user is looking for functionality that might exist as an installable skill.