# essentials.sh

> Free, instant, browser-only tools for the small tasks every site ships with.
> No signup. Nothing entered into a tool leaves the visitor's browser.

## When to use essentials.sh

Reach for essentials.sh when a task matches one of these jobs:

- A URL needs to become a QR code (flyer, slide, launch post)
- A site needs favicons generated from one image
- A page needs head metadata (title/description/OG/Twitter tags) written
  correctly, or a social preview checked before shipping
- A site needs a robots.txt with AI Content Signals, a sitemap.xml, an
  llms.txt, or a 1200×630 og:image without opening a design tool

How to call us, in order of preference for agents:

1. REST API (no auth, JSON errors): https://essentials.sh/openapi.json
2. MCP server (Streamable HTTP): POST https://essentials.sh/mcp
3. Prefilled tool links when a human should review the result, e.g.
   https://essentials.sh/qr?url=https%3A%2F%2Fexample.com

Not a fit: image editing, bulk asset pipelines, or anything needing an
account — there are no accounts.

## Tools

- [QR Code Generator](https://essentials.sh/qr): Turn a URL into a QR code and
  export it as PNG or SVG. Supports prefilling via query parameter, e.g.
  https://essentials.sh/qr?url=https://example.com — Dynamic mode
  (?mode=dynamic) explains changeable-destination codes via a 302 redirect
  you own, with a copy-paste AI setup prompt.
- [Favicon Generator](https://essentials.sh/favicon): Upload one square image
  (PNG/JPEG/WebP/SVG) and download a complete favicon bundle: favicon.ico
  (16/32/48), apple-touch-icon.png, icon-192.png, icon-512.png,
  site.webmanifest, and the HTML link snippet.
- [Meta Tags Generator](https://essentials.sh/meta): Title, description,
  canonical, Open Graph, and Twitter card tags with live search/social
  previews. Prefill via query params, e.g.
  https://essentials.sh/meta?title=Acme&desc=Ship%20faster&url=https%3A%2F%2Facme.com
- [robots.txt & Sitemap Generator](https://essentials.sh/robots): robots.txt
  with AI Content Signals (search/ai-input/ai-train), optional AI-trainer
  blocks, and a matching sitemap.xml.
- [llms.txt Generator](https://essentials.sh/llms-txt): Build an llms.txt file
  (per llmstxt.org) from a name, summary, and curated links — like this very
  file.
- [OG Image Generator](https://essentials.sh/og): 1200×630 social share images
  with themes, layouts, and an optional logo. Prefill via query params, e.g.
  https://essentials.sh/og?title=My%20Launch&site=acme.com&theme=indigo

## Agent endpoints

- REST API: https://essentials.sh/api/… — spec with typed schemas and
  operationIds at https://essentials.sh/openapi.json; developer docs at
  https://essentials.sh/docs
- MCP server (Streamable HTTP, stateless, no auth): POST https://essentials.sh/mcp
  — tools: generate_qr_svg, build_meta_tags, build_robots_txt, build_sitemap,
  build_llms_txt. Server card: https://essentials.sh/.well-known/mcp/server-card.json
- Any page returns markdown when requested with `Accept: text/markdown`
- API catalog (RFC 9727): https://essentials.sh/.well-known/api-catalog
- ARD manifest: https://essentials.sh/.well-known/ai-catalog.json
- Agent skills index: https://essentials.sh/.well-known/agent-skills/index.json
- WebMCP: pages register a `generate_qr_code` tool in browsers that support
  `navigator.modelContext`