App-Kit

App-Kit MCP

Remote MCP server for SEO audits, text readability and grammar checks, image conversion (PNG/JPEG/WebP) and PDF to images - for Claude, Cursor, VS Code, Windsurf and any other MCP client. Free, with daily limits. Two addresses:

https://mcp.app-kit.dev/mcp            # no account: anonymous or with a free token
https://mcp.app-kit.dev/mcp/account    # with a free App-Kit account (OAuth sign-in), higher limits

Русская версия | Tools reference | app-kit.dev

This repository holds the public documentation, client configs and registry metadata. The server itself is a hosted service operated by App-Kit; there is nothing to install.

What it does

• SEO audit of a website - score 0-100 by group, failed checks and the five biggest losses. The engine runs 400 checks (technical SEO, performance, structured data, AI-readiness and more); the fast mode covers up to 10 pages in about a minute.
• Text check - readability, "water" and keyword stuffing metrics, stop phrases and grammar (LanguageTool) for Russian and English, up to 20 000 characters. Returns positions of issues, not copies of your text.
• PDF and images - PDF pages to PNG/JPEG/WebP, images to PDF, format conversion and WebP/AVIF compression. Files are passed by URL or via a one-time upload link, never as huge base64 strings in the chat.

Quick start

There are two ways to connect:

• Without an account - https://mcp.app-kit.dev/mcp. Works anonymously out of the box; a free token (no email) gives you limits of your own.
• With an App-Kit account - https://mcp.app-kit.dev/mcp/account. Accepts only account sign-in (OAuth 2.1 with PKCE): your client opens the App-Kit sign-in page in the browser, you sign in or create an account (email and password) and approve access. Highest limits, no tokens to copy. Create an account in advance at admin.app-kit.dev/oauth/signup or from the sign-in page your client opens.

With an App-Kit account

• Claude.ai and Claude Desktop: Customize > Connectors > + > Add custom connector. Name: App-Kit, Remote MCP server URL: https://mcp.app-kit.dev/mcp/account. Click Connect and sign in. Details: examples/claude-desktop/claude.ai.md.

• Claude Code:

  claude mcp add --transport http app-kit https://mcp.app-kit.dev/mcp/account
  

  Then run /mcp in Claude Code and choose Authenticate for app-kit.

• Cursor, VS Code and other clients with MCP OAuth support: use the same URL without headers (Cursor, VS Code); the client opens the sign-in page on first use.

• ChatGPT: coming later.

Without an account

Works anonymously out of the box. For higher limits, get a free token on app-kit.dev/mcp (one click, no email) and pass it either as a header Authorization: Bearer mcpf_... or in the URL: https://mcp.app-kit.dev/mcp/t/mcpf_....

Claude Code

claude mcp add --transport http app-kit https://mcp.app-kit.dev/mcp

# with a free token
claude mcp add --transport http app-kit https://mcp.app-kit.dev/mcp \
  --header "Authorization: Bearer mcpf_your_token"

Add --scope user to make it available in every project. See examples/claude-code.sh.

Claude.ai and Claude Desktop

Customize > Connectors > + > Add custom connector. Name: App-Kit, Remote MCP server URL: https://mcp.app-kit.dev/mcp/t/mcpf_your_token (the token in the URL is recommended: requests from claude.ai share Anthropic's IP addresses, so anonymous limits there are a small shared pool). Authentication: no sign-in. Free Claude plans allow one custom connector. Details: examples/claude-desktop/claude.ai.md.

Cursor

.cursor/mcp.json in the project or ~/.cursor/mcp.json globally (example):

{
  "mcpServers": {
    "app-kit": {
      "url": "https://mcp.app-kit.dev/mcp",
      "headers": { "Authorization": "Bearer mcpf_your_token" }
    }
  }
}

VS Code (GitHub Copilot agent mode)

.vscode/mcp.json (example); VS Code asks for the token once and stores it securely:

{
  "inputs": [
    { "type": "promptString", "id": "app-kit-token", "description": "App-Kit MCP free token (mcpf_...)", "password": true }
  ],
  "servers": {
    "app-kit": {
      "type": "http",
      "url": "https://mcp.app-kit.dev/mcp",
      "headers": { "Authorization": "Bearer ${input:app-kit-token}" }
    }
  }
}

Windsurf (Devin Desktop)

Open the MCP config from the Cascade MCP settings (mcp_config.json) and add a server with serverUrl. ${env:VAR} is expanded in headers:

{
  "mcpServers": {
    "app-kit": {
      "serverUrl": "https://mcp.app-kit.dev/mcp",
      "headers": { "Authorization": "Bearer ${env:APPKIT_MCP_TOKEN}" }
    }
  }
}

Cline

cline_mcp_settings.json (MCP Servers > Configure). Set "type": "streamableHttp": without it Cline uses the legacy SSE transport. Agent-oriented steps: llms-install.md.

{
  "mcpServers": {
    "app-kit": {
      "type": "streamableHttp",
      "url": "https://mcp.app-kit.dev/mcp",
      "headers": { "Authorization": "Bearer mcpf_your_token" }
    }
  }
}

Gemini CLI

Install as an extension (the repo root has gemini-extension.json):

gemini extensions install https://github.com/app-kit-dev/mcp

or add the server to ~/.gemini/settings.json (httpUrl = Streamable HTTP):

{
  "mcpServers": {
    "app-kit": {
      "httpUrl": "https://mcp.app-kit.dev/mcp",
      "headers": { "Authorization": "Bearer mcpf_your_token" }
    }
  }
}

Other clients

Any client that supports remote MCP over Streamable HTTP: URL https://mcp.app-kit.dev/mcp, optional header Authorization: Bearer mcpf_.... Clients that cannot set headers can use https://mcp.app-kit.dev/mcp/t/mcpf_.... Clients with MCP OAuth support can use https://mcp.app-kit.dev/mcp/account instead.

Tools

Full descriptions and JSON Schemas: docs/tools.md (generated from the live tools/list).

Tool	What it does	Example prompt
seo_audit_fast	Fast SEO audit of a site root (up to 10 pages): score, failed checks, top-5 losses. Waits up to 60 s, then returns a handle	"Run an SEO audit of example.com and tell me what to fix first"
seo_audit_status	Status and result of an audit by handle	(called by the model automatically)
text_check	Readability, water/spam metrics, stop phrases, grammar; lang ru/en, up to 20 000 chars	"Check this landing page copy for readability and grammar: ..."
quota_status	Your access level and remaining free calls per tool	"How many free App-Kit checks do I have left today?"
image_convert	Convert between PNG, JPEG, WebP, BMP, TIFF, GIF	"Convert this logo to PNG: https://example.com/logo.webp"
pdf_to_images	Render PDF pages (up to 20) to PNG/JPEG/WebP	"Turn pages 1-3 of https://example.com/deck.pdf into PNG at 150 dpi"
images_to_pdf	Merge up to 20 images into one PDF	"Make a PDF from these 3 screenshots: ..."
conversion_status	Status and result of a long conversion by handle	(called by the model automatically)
create_upload	One-time upload URL for a local file (agents with a shell)	"Convert ./scan.pdf to PNG pages"
image_compress	Compress to WebP/AVIF with quality and resize options	"Compress https://example.com/hero.png to AVIF"

All tools are read-only: nothing is published or changed on your side. Results that are files come back as short-lived download links (10 minutes) plus a small preview.

Limits

Limits are per tool, per day, and reset at 00:00 UTC.

Tool	Anonymous	Free token	App-Kit account	Notes
text_check	3 / day	5 / day	20 / day
seo_audit_fast	1 / day	2 / day	5 / day	one domain: up to 5 audits per day from all users
seo_audit_status, conversion_status, quota_status	free	free	free	do not spend quota
image_convert	2 / day	3 / day	10 / day
pdf_to_images, images_to_pdf	1 / day	2 / day	5 / day	up to 20 pages / files, 20 MB
create_upload	3 / day	5 / day	15 / day	up to 20 MB, link valid 10 min

Anonymous requests from claude.ai share one small hourly pool (Anthropic's shared IP range). Every response includes quota (remaining, reset_at, tier, upgrade_url). There is also a shared daily budget per tool; when it runs out, the tool says so and resets at 00:00 UTC. Limits may be tuned without notice; the current values are always in the tool descriptions and quota_status.

Pricing

The free tier above stays free. Higher limits, full multi-page SEO audits with PDF reports and larger files are part of the paid App-Kit API and are billed in App-Kit credits - see app-kit.dev.

Privacy

• Processing happens in Germany (EU).
• Text you send to text_check is not stored; only metrics are returned.
• Files are kept only while being processed and deleted within 15 minutes; download links expire in 10 minutes.
• IP addresses are used only for anonymous rate limits, as a salted hash kept for at most 24 hours.
• App-Kit accounts (only for /mcp/account): email, password hash, sign-up date and source, stored in Germany; OAuth tokens are stored as hashes (access 1 hour, refresh 30 days). To delete your account, write to [email protected].
• Usage logs contain the tool name, timing and status - no IP addresses, texts, file contents or full URLs.
• Page content from audited sites is never returned verbatim: only scores, check codes and short, clipped fields marked as page data.

Full policy: app-kit.dev/privacy.

FAQ

Do I need an account? No. Anonymous use works; a free token (no email) raises the limits. An App-Kit account (/mcp/account) gives the highest limits and signs you in through the browser.

Why do anonymous calls from claude.ai run out quickly? claude.ai connects from Anthropic's shared IP range, so all anonymous claude.ai users share one small pool. Use a token in the URL.

Can it audit my staging site? Only publicly reachable sites. Private networks, localhost and non-standard ports are blocked.

Which MCP protocol versions are supported? Streamable HTTP, stateless: current MCP revisions and clients on 2025-11-25. No stdio package is needed.

A long audit returned status: running. What now? The model calls seo_audit_status with the handle after poll_after_s seconds. The handle works only for the caller and expires in 60 minutes.

Is the server open source? The server is a hosted service. This repository (docs, examples, registry metadata) is MIT-licensed.

Where do I get help? Email [email protected] (questions, account deletion, problems with the server). Bugs and ideas: issues. Security: see SECURITY.md.

Links

• Free token and docs: app-kit.dev/mcp
• Account sign-up: admin.app-kit.dev/oauth/signup
• Support: [email protected]
• Privacy: app-kit.dev/privacy, terms: app-kit.dev/terms
• App-Kit: app-kit.dev
• MCP Registry name: io.github.app-kit-dev/mcp (server.json)