Babysitter is a workflow engine for AI coding agents that enforces predefined steps, quality checks, human approvals, and decision records. It is used to coordinate complex, repeatable agent workflows across supported coding tools. The catalogue contains skills, agents, instructions, settings, a plugin, and an MCP integration for its workflow.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add a5c-ai/babysitter --skill mcp-host-styling-integrationgit clone --depth 1 https://github.com/a5c-ai/babysitterWrote 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/a5c-ai/babysitter/mcp-host-styling-integration)<a href="https://agentmods.dev/skills/a5c-ai/babysitter/mcp-host-styling-integration"><img src="https://agentmods.dev/badge/skills/a5c-ai/babysitter/mcp-host-styling-integration/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/a5c-ai/babysitter/mcp-host-styling-integration"><img src="https://agentmods.dev/badge/skills/a5c-ai/babysitter/mcp-host-styling-integration.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00044 | $0.02536 |
| Opus 5 | $0.00022 | $0.01268 |
| Sonnet 5 | $0.00009 | $0.00507 |
| Haiku 4.5 | $0.00004 | $0.00254 |
Grade A, and why
mcp-host-styling-integration 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 5d 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 — 300 lines — stays where its author put it; the contents beside it link to each section on GitHub.
mcp-host-styling-integration
Integrate MCP App UIs with the host application's theming system so apps look native in Claude Desktop, ChatGPT, VS Code, Goose, Postman, and other MCP-enabled hosts.
Overview
MCP Apps render in sandboxed iframes inside host applications. Each host has its own visual theme (colors, fonts, border radii, spacing). The MCP Apps SDK provides:
- CSS variables (
--color-*,--font-*,--border-radius-*) injected by the host - SDK helpers (
applyDocumentTheme,applyHostStyleVariables,applyHostFonts) to apply them - React hooks (
useHostStyles,useHostStyleVariables,useHostFonts) for React apps onhostcontextchangedevent fired when theme changes (e.g., dark mode toggle)
The key principle is: always use CSS variable fallbacks so the app looks correct both as an MCP App (host provides variables) and standalone (fallback values apply).
Capabilities
Host CSS Variable Integration
- Apply all host CSS variables with sensible fallback values
- Support color variables:
--color-background-primary,--color-background-secondary,--color-text-primary,--color-text-secondary,--color-border-primary - Support font variables:
--font-sans,--font-mono,--font-text-base-size,--font-text-sm-size - Support layout variables:
--border-radius-sm,--border-radius-md,--border-radius-lg
onhostcontextchanged Handler
- Listen for theme changes from the host
- Reapply styling when theme changes (e.g., light to dark mode)
- Access host context: theme, display mode, safe area insets
Safe Area Insets
- Apply safe area padding for mobile or embedded contexts
- Handle
env(safe-area-inset-top),env(safe-area-inset-bottom), etc.
Display Mode Detection
- Detect embedded vs fullscreen mode
- Adapt layout based on available space
- Configure fullscreen mode via tool metadata
SDK Helper Functions
applyDocumentTheme(theme)-- sets document-level theme classapplyHostStyleVariables(context)-- applies all CSS variables from hostapplyHostFonts(context)-- loads and applies host fonts
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 5d ago First seen · 300 lines · 44 tokens per session scan A 93004c18d8e2
mcp-host-styling-integration is a skill published in the GitHub repository a5c-ai/babysitter (1,788 stars, last pushed 5d ago), licensed MIT. It adds 44 tokens to every session and 2,536 once invoked, about $0.0002 per session on Opus 5. 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 2026-09-05.
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