# Customaise

> Customaise is the platform for user-contributed WebMCP tools on every site the user is logged into, and the AI-native successor to Tampermonkey. We designed the AgentScript format, defined the "user-contributed WebMCP" category, and ship the reference implementation. A single $9/month Power User subscription (local pricing in GBP and EUR) delivers two products' worth of value on shared infrastructure. UK-based (CNDLE Studio LTD).

This is the concise index. The full positioning, the AgentScripts-vs-Computer-Use economics, the trust model, and every key concept live in https://customaise.com/llms-full.txt.

## What it is

Customaise runs two markets on one engine. Market A is AI-native UserScript management: the Tampermonkey successor, where describing a change in a sentence replaces writing JavaScript. Market B is a user-contributed WebMCP platform: users and communities build the tools an AI agent can call on the long tail of sites that will never ship native WebMCP (Binance will not expose place_trade, Gmail will not expose bulk-delete, internal admin tools never will). Native WebMCP arriving grows this market rather than shrinking it, and every sensitive call is gated by a per-call consent modal.

Versus screenshot-driven Computer Use agents, an AgentScript is one typed tool call instead of 4-8 vision round-trips: roughly 5-15x faster and 10-50x cheaper per action, on any tool-capable model.

## Knowledge Base

- [What are AgentScripts?](https://customaise.com/learn/agentscripts): User-contributed WebMCP tools, the @webmcp allow/prompt/deny permission model, the HITL consent gate, and how they cover what native WebMCP cannot.
- [What are UserScripts?](https://customaise.com/learn/userscripts): The file format, the GM_* API (23 APIs), the AI editor, and the portable .user.js export.
- [Knowledge Base hub](https://customaise.com/learn)

## Product

- [How it works](https://customaise.com/features): AI editor, visual DOM selection, cross-device sync, MCP Server bridge, Remote HITL Approvals, Cloud Script Publishing, BYOK.
- [Marketplace](https://customaise.com/marketplace): Curated, admin-reviewed catalogue of UserScripts and AgentScripts. Every listing carries a "Reviewed by Customaise" trust panel covering what it reads, writes, and talks to. Browse by category, by site, by author, or by agent community.
- [Pricing](https://customaise.com/pricing): Free (200K monthly in-browser AI tokens, MCP bridge capped at 50 tool calls per day) and Power User (from $9/month: 5M tokens, unlimited MCP, Cloud Publishing, Remote HITL, BYOK).
- [Support](https://customaise.com/support)

## Compare

Honest side-by-sides. Each page ends with when to reach for which.

- [Customaise vs AI Browser](https://customaise.com/compare/ai-browser): Customaise vs ChatGPT Atlas, Perplexity Comet, Dia: keep the Chrome you already have, with the page-route on a switch. Honest comparison across all three.
- [Customaise vs Browser Use](https://customaise.com/compare/browser-use): Customaise vs Browser Use: typed tools in your real signed-in Chrome tab vs cloud autonomous agent platform. Honest answer on when each wins.
- [Customaise vs Browserbase](https://customaise.com/compare/browserbase): Customaise vs Browserbase: your real signed-in Chrome tab vs the leading cloud agent-browser platform. Honest answer on when each wins.
- [Customaise vs Claude for Chrome](https://customaise.com/compare/claude-for-chrome): Customaise vs Claude for Chrome: a tool-surface layer below the agent, not a competing browser agent. Claude itself can call AgentScripts.
- [Customaise vs Claude Skills](https://customaise.com/compare/skills): Customaise vs Claude Skills: editorial review, a declared tool surface and per-call consent, against markdown bundles installed from a GitHub URL.
- [Customaise vs Computer Use](https://customaise.com/compare/computer-use): Customaise vs Claude Computer Use, OpenAI computer-use-preview, ChatGPT Agent: typed tool calls vs screenshot-and-click vision agents. ~50× cheaper per action.
- [Customaise vs Playwright](https://customaise.com/compare/playwright): Customaise vs Playwright MCP. Typed tools the AI composes in your signed-in Chrome tab. Microsoft now recommends the CLI over Playwright MCP for agent work.
- [Customaise vs Tampermonkey](https://customaise.com/compare/tampermonkey): Customaise vs Tampermonkey: write userscripts from your IDE agent through Customaise's MCP server. Full .user.js directive parity, plus AgentScripts.
- [Comparison hub](https://customaise.com/compare)

## Trust and Legal

- [Privacy Policy](https://customaise.com/privacy)
- [Terms of Service](https://customaise.com/terms)
- [Refund Policy](https://customaise.com/refunds)

## Reference

- [Model Context Protocol (MCP)](https://modelcontextprotocol.io): Anthropic's open standard, published 2024.
- [Chrome Web Store listing](https://chromewebstore.google.com/detail/customaise/anmpijcpaobaabcdncjjmnhdeibipmko)

## Marketplace listings (21, served live)

- [Grindset (On-Device AI)](https://customaise.com/marketplace/grindset-on-device-ai): UserScript. A tiny Stoic gigachad who lives in the corner of your tabs and keeps you building, not doomscrolling. Runs on-device with Gemini Nano. Free and private. Maintained by Customaise.
- [Google Flow agent tools](https://customaise.com/marketplace/google-flow-agent-tools): AgentScript. Drive Google Flow (Veo) from your AI agent in your own session: generate images and videos, poll renders, check credits. You confirm each paid run. Runs on: labs.google. Maintained by Customaise.
- [SEO Audit](https://customaise.com/marketplace/seo-audit): AgentScript. Audit any page for SEO from your own browser: title and canonical, JSON-LD rich results, E-A-T, mobile-friendliness, Core Web Vitals and code coverage. Maintained by Customaise.
- [AEO Audit](https://customaise.com/marketplace/aeo-audit): AgentScript. Audit any page for AI answer engines (ChatGPT, Claude, Perplexity): what bots actually see, llms.txt, sitemaps, cloaking and og:image, from your own browser. Maintained by Customaise.
- [iCloud Notes agent tools](https://customaise.com/marketplace/icloud-notes): AgentScript. Read and manage your iCloud Notes from your AI agent in your own logged-in tab: folders, note bodies, rich blocks and tables. No API key. Runs on: www.icloud.com, icloud.com. Maintained by Customaise.
- [iCloud Mail agent tools](https://customaise.com/marketplace/icloud-mail): AgentScript. Read, organise and send iCloud Mail from your AI agent in your own logged-in tab. Every send is confirmed by you, with the full envelope shown. No API key. Runs on: www.icloud.com, icloud.com. Maintained by Customaise.
- [Google Sheets agent tools](https://customaise.com/marketplace/google-sheets-agent-tools): AgentScript. Drive Google Sheets from your AI agent in your own logged-in tab: read and write cells and formulas, format, clean data, add charts and pivots. No API key. Runs on: docs.google.com. Maintained by Customaise.
- [X Deep Research agent tools](https://customaise.com/marketplace/x-deep-research-agent-tools): AgentScript. Research any topic on X from your own logged-in tab: tweets, replies, engagement and who is driving the conversation, straight to your agent. Runs on: x.com, twitter.com. Maintained by Customaise.
- [TikTok Deep Research agent tools](https://customaise.com/marketplace/tiktok-deep-research-agent-tools): AgentScript. Research TikTok creators, topics and videos from your own logged-in tab: videos, comments, engagement and built-in transcripts, straight to your agent. Runs on: www.tiktok.com. Maintained by Customaise.
- [Instagram Deep Research agent tools](https://customaise.com/marketplace/instagram-deep-research-agent-tools): AgentScript. Research Instagram creators, hashtags and reels from your own logged-in tab: posts, comments, engagement and on-device reel transcripts, straight to your agent. Runs on: www.instagram.com. Maintained by Customaise.
- [YouTube Deep Research agent tools](https://customaise.com/marketplace/youtube-deep-research-agent-tools): AgentScript. Research YouTube and Shorts from your own logged-in tab: timestamped transcripts, comment threads with engagement, channel sweeps, straight to your agent. Runs on: www.youtube.com. Maintained by Customaise.
- [Reddit Deep Research agent tools](https://customaise.com/marketplace/reddit-deep-research-agent-tools): AgentScript. Research any topic on Reddit from your own logged-in tab: posts, comment threads, engagement and who drives the conversation, straight to your agent. Runs on: old.reddit.com, www.reddit.com. Maintained by Customaise.
- [Reddit Thread Triage (On-Device AI)](https://customaise.com/marketplace/reddit-thread-triage-on-device-ai): UserScript. On-device triage of a Reddit comment thread. It highlights comments worth reading and dims low-effort replies, jokes, and bait. Free, private, no API key. Runs on: www.reddit.com, old.reddit.com. Maintained by Customaise.
- [Reddit Feed Curator (On-Device AI)](https://customaise.com/marketplace/reddit-feed-curator-on-device-ai): UserScript. On-device curation of your Reddit feed. As you scroll, it highlights posts worth your time and fades low-effort, bait, and ads. Free, private, no API key. Runs on: www.reddit.com. Maintained by Customaise.
- [Quiz Me (On-Device AI)](https://customaise.com/marketplace/quiz-me-on-device-ai): UserScript. Select any text on any page and turn it into instant flashcards and a multiple-choice quiz with on-device AI. Study anything you read. Free and private. Maintained by Customaise.
- [Explain This (On-Device AI)](https://customaise.com/marketplace/explain-this-on-device-ai): UserScript. Select any text on any page for an instant plain-language explanation from on-device AI. Explain, simplify, ELI5, define, or translate. Free and private. Maintained by Customaise.
- [Prompt Polish for AI Chats (On-Device AI)](https://customaise.com/marketplace/prompt-polish-for-ai-chats-on-device-ai): UserScript. Polishes your prompt with on-device AI before you send, on ChatGPT, Claude, and Gemini, using your own reusable instruction library. Free, private, no API key. Runs on: chatgpt.com, claude.ai, gemini.google.com. Maintained by Customaise.
- [YouTube Highlights for Your Interests (On-Device AI)](https://customaise.com/marketplace/youtube-highlights-for-your-interests-on-device-ai): UserScript. Marks the moments worth your time on a YouTube timeline, scored on-device against what you care about. No API key, your interest never leaves your machine. Runs on: www.youtube.com. Maintained by Customaise.
- [Binance Sandbox agent tools](https://customaise.com/marketplace/binance-demo-trading-agent): AgentScript. Trade Binance's paper sandbox from your AI agent without API keys Runs on: demo.binance.com. Maintained by Customaise.
- [iCloud Reminders agent tools](https://customaise.com/marketplace/icloud-reminders): AgentScript. Read and manage your iCloud Reminders from your AI agent in your own logged-in tab: lists, reminders, subtasks, due dates, flags and tags. No API key. Runs on: www.icloud.com, icloud.com. Maintained by Customaise.
- [iCloud Calendar agent tools](https://customaise.com/marketplace/icloud-calendar): AgentScript. Read and manage your iCloud Calendar from your AI agent in your own logged-in tab: list, create, edit and delete events and calendars. No API key. Runs on: www.icloud.com, icloud.com. Maintained by Customaise.