Shiny for Python is a Python framework for building interactive web applications and data visualizations with reactive behavior. Data scientists and Python developers use it for prototypes as well as larger applications. Its bundled agent skills provide coding agents with Shiny documentation so they can create better Shiny applications.
Borrowing it
Nothing to install: this file belongs to posit-dev/py-shiny. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/posit-dev/py-shiny/main/.agents/skills/port-from-bslib/SKILL.mdgit clone --depth 1 https://github.com/posit-dev/py-shinyWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/posit-dev/py-shiny/port-from-bslib)<a href="https://agentmods.dev/skills/posit-dev/py-shiny/port-from-bslib"><img src="https://agentmods.dev/badge/skills/posit-dev/py-shiny/port-from-bslib/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/posit-dev/py-shiny/port-from-bslib"><img src="https://agentmods.dev/badge/skills/posit-dev/py-shiny/port-from-bslib.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 236 Skill allows unbounded resource consumption (API calls, storage, compute). Without rate limits or quotas, a compromised or misbehaving agent can cause denial-of-service or cost overruns.Fix: Set explicit rate limits, timeouts, and resource quotas for API calls, file operations, and compute. Implement circuit breakers for runaway loops.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.05237 |
| Opus 5.5 | $0.00000 | $0.02095 |
| Sonnet 5.5 | $0.00000 | $0.01047 |
| Haiku 4.5 | $0.00000 | $0.00524 |
Grade A, and why
port-from-bslib scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 567 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Porting Components from bslib to py-shiny
This guide explains how to port new UI components from the R bslib package to py-shiny. It assumes you're an experienced developer familiar with Python, R, and JavaScript/TypeScript, but may be new to the specifics of these repositories.
Background
The bslib R package serves as the primary development location for new Bootstrap 5 components in the Shiny ecosystem. Components developed in bslib are then ported to py-shiny to maintain feature parity between Shiny for R and Shiny for Python.
Key relationship: bslib provides both the R implementation and the compiled JavaScript/CSS assets that py-shiny vendors and uses directly.
Overview of the Porting Process
The porting process involves three main phases:
- Understanding the source - Study the bslib implementation (R, TypeScript, SCSS)
- Implementing the port - Create Python equivalents and add client-side bindings
- Testing and documentation - Ensure correctness with unit and end-to-end tests
Phase 1: Understanding the Source Implementation
Step 1.1: Locate the bslib PR
Find the bslib PR that introduced the feature. The py-shiny PR description should reference it (e.g., Related https://github.com/rstudio/bslib/pull/...).
Checklist:
- Located the bslib PR
- Reviewed the PR description and any design discussions
Step 1.2: Identify the core source files
In the bslib PR, locate these key files:
- R implementation:
R/[feature-name].R- The main component function(s) - TypeScript bindings:
srcts/src/components/[featureName].ts- Client-side behavior - SCSS styles:
inst/components/scss/[feature_name].scss- Component styles - Unit tests:
tests/testthat/test-[feature-name].R- R unit tests
Note: Generated files (compiled JS/CSS, documentation) can be ignored - focus on source files.
Checklist:
- Found the R implementation file(s)
- Found the TypeScript source file(s)
- Found the SCSS source file
- Found the unit test file(s)
- Reviewed how TypeScript is registered in
srcts/src/components/index.ts
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +3 lines 17978a69e613
- 2mo ago First seen · 564 lines · 0 tokens per session scan A a5104aa16fdc
port-from-bslib is a skill published in the GitHub repository posit-dev/py-shiny (1,767 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 5,237 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
port-from-bslib compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| port-from-bslibposit-dev/py-shiny | Skill | 1.8k | yesterday | MIT | A | 0 | Claude Code, Codex |
| anti-slop-designsickn33/agentic-awesome-skills | Skill | 49k | yesterday | MIT | A | 34 | Claude Code |
| chakra-ui-builderchakra-ui/chakra-ui | Skill | 41k | yesterday | MIT | A | 214 | Claude Code, Codex |
| visual-ralphYeachan-Heo/oh-my-codex | Skill | 34k | 3d ago | MIT | A | 52 | Codex |
| open-design-setupcompozy/compozy | Skill | 2.8k | today | MIT | A | 67 | Claude Code, Codex |
| edit-sitemicrosoft/power-platform-skills | Skill | 1.1k | today | MIT | A | 104 | Claude Code |
| frontend-visual-qadaymade/claude-code-skills | Skill | 1.5k | yesterday | MIT | A | 125 | Claude Code, Codex |