Browse reusable Agent Skills, each with a clear purpose and practical guidance.
Assesses whether branch or PR changes are high-risk for externally hosted or embedded Streamlit usage and recommends whether external e2e coverage with `@pytest.mark.external_test` is needed. Use during code review, PR triage, or test planning when changes touch routing, auth, websocket/session behavior, embedding, assets, cross-origin behavior, SiS/Snowflake runtime, storage, or security headers.
Validates all code changes before committing by running format, lint, type, and unit test checks. Use after making backend (Python) or frontend (TypeScript) changes, before committing or finishing a work session.
Creates a draft pull request on GitHub with proper labels, branch naming, and description formatting. Use when changes are ready to be submitted as a PR to the streamlit/streamlit repository.
Finalizes branch changes for merging by simplifying code, running checks, reviewing changes, and creating a PR if needed. Use when ready to merge changes into the target branch.
Implement a feature from a product/tech spec, URL, or GitHub issue. Reads the spec, implements the feature following Streamlit patterns, and creates a merge-ready PR. Use when given a spec folder path, document URL, or issue link to implement.
Runs Python unit tests with coverage, analyzes coverage reports, and implements meaningful tests to increase coverage by ~0.2%. Use when you want to systematically improve Python test coverage with high-value test cases.
Explains Streamlit's internal architecture including backend runtime, frontend rendering, and WebSocket communication. Use when debugging cross-layer issues, understanding how features work end-to-end, planning architectural changes, or onboarding to the codebase. Covers ForwardMsg/BackMsg protocol, script rerun model, element tree, widget state management, and more.
Writes product and tech specs for new Streamlit features. Use when designing new API commands, widgets, or significant changes that need team review before implementation.
**[REQUIRED]** Use for ALL Streamlit tasks: creating, editing, debugging, beautifying, styling, theming, or optimizing Streamlit applications. Also required for building custom components (inline or packaged), using st.components.v2, or any HTML/JS/CSS component work. Triggers: streamlit, st., dashboard, app.py, beautify, style, CSS, color, background, theme, button, widget styling, custom component, st.components, packaged component, pyproject.toml, asset_dir, CCv2, HTML/JS component.
Lists available make commands for Streamlit development. Use for build, test, lint, or format tasks.