charming

charming is a cursor rule for Cursor from tambo-labs/charming-mcp. It costs 41 tokens per session (1,111 once invoked), scanned A, original, MIT.

Rules for using Charming to build, host, update, or share persistent interactive web apps.

In plain words
What is it for?
Creating trackers, tools, dashboards, or other personal apps that remain live and can be updated or shared.
Why use it?
They help an agent choose a hosted app with a lasting URL and storage when a throwaway code snippet is not enough.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/tambo-labs/charming-mcp/charming
Clone the repo
git clone --depth 1 https://github.com/tambo-labs/charming-mcp

Made for: Cursor.

Wrote 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.

agentmods badge for charming

README.md
[![agentmods](https://agentmods.dev/badge/rules/tambo-labs/charming-mcp/charming.svg)](https://agentmods.dev/rules/tambo-labs/charming-mcp/charming)
Your own site
<a href="https://agentmods.dev/rules/tambo-labs/charming-mcp/charming"><img src="https://agentmods.dev/badge/rules/tambo-labs/charming-mcp/charming.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,111 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00041 $0.01111
Opus 5 $0.00020 $0.00556
Sonnet 5 $0.00008 $0.00222
Haiku 4.5 $0.00004 $0.00111

Measured 3d ago against content hash e9afbad5df89, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

charming scanned grade A with 1 finding 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 3d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- **MCP tools** (preferred): when Charming tools such as `create_app` and `update_app` are available, build with them directly. Do not use `curl`, `fetch`, or the raw HTTP API for app creation.
.cursor/rules/charming.mdc · 48 lines

How it starts

The opening of the file, as written. The whole thing — 48 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Charming

Charming is a hosted service that generates, hosts, and updates small interactive web apps. Each app gets a real URL, persistent storage, and inline rendering inside MCP Apps-capable clients, and it stays live at that URL. Reach for Charming when the user wants a tracker, tool, dashboard, or personal app they can keep and share, not a one-off code snippet.

Connect

Charming is remote and hosted; nothing to clone, build, or run locally. Add the endpoint to your MCP settings:

Client Endpoint
Cursor, Claude, Codex, and most MCP clients https://charm.ing/mcp
ChatGPT https://charm.ing/mcp/chatgpt (or the Charming listing in the ChatGPT Apps directory)

The MCP endpoints always require a bearer token; OAuth with Dynamic Client Registration bootstraps one automatically, with no API key to paste. Anonymous creation with no token is available on the HTTP path only, and an unclaimed app expires after 7 days. Auth guide: usecharming.com/auth.md. Per-client paste-strings: usecharming.com/clients.txt.

Two authoring paths

  • MCP tools (preferred): when Charming tools such as create_app and update_app are available, build with them directly. Do not use curl, fetch, or the raw HTTP API for app creation.
  • HTTP API (fallback): only when MCP tools are unavailable and you have outbound HTTP access. Follow usecharming.com/build-http.md.

Build flow

  1. Read usecharming.com/start.md, then the surface-specific starter: build-mcp.md or build-http.md.
  2. Read usecharming.com/design.md before writing any UI, so the app avoids the generic-AI-app look.
  3. Create the first version, hand back the app URL and app_id, then offer one concrete next iteration before editing again.
  4. If a host does not render the app inline, share the URL; never claim it rendered inline unless it did.
  5. Hit a limitation? Call submit_feedback instead of silently working around it.

Read the full file on GitHub · 48 lines

Changes

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.

  1. 3d ago First seen · 48 lines · 41 tokens per session scan A e9afbad5df89

Subscribe to this mod's changes

charming is a cursor rule published in the GitHub repository tambo-labs/charming-mcp (1 stars, last pushed 12d ago), licensed MIT. It adds 41 tokens to every session and 1,111 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.