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Tachtien

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Look up the Dutch word tachtien (uncountably many) and rewrite vague amounts as tachtien.

Source code Website Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http tachtien 'https://mcp.tachtien.nl/mcp'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "tachtien": {
            "type": "http",
            "url": "https://mcp.tachtien.nl/mcp"
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Tachtien MCP
  2. Connect
  3. ChatGPT
  4. Other compatible MCP clients
  5. Examples
  6. Tools
  7. Prompts
  8. Develop
  9. Author

Tachtien MCP

An MCP server for the Dutch word tachtien: ontelbaar veel, uncountably many. Look up the word, its examples and mentions, rewrite vague amounts as tachtien, or ask whether something counts as tachtien.

Endpoint: https://mcp.tachtien.nl/mcp (Streamable HTTP, stateless, no auth) Server card: /.well-known/mcp/server-card.json

Connect

claude mcp add --transport http tachtien https://mcp.tachtien.nl/mcp

ChatGPT

In ChatGPT on the web: open Plugins, choose + and then Add custom MCP server. Name it, for example, Tachtien, enter https://mcp.tachtien.nl/mcp as the endpoint, choose no authentication and finish creating it. Then install the plugin and use @Tachtien in a new chat.

Whether you can add your own MCP servers depends on your ChatGPT plan and your workspace settings. See the official ChatGPT setup guide for current steps.

Other compatible MCP clients

{ "mcpServers": { "tachtien": { "type": "http", "url": "https://mcp.tachtien.nl/mcp" } } }

Examples

Ask Claude, or any MCP client, things like these. The answers are in Dutch, like the content.

  • "What does the Dutch word tachtien mean, how do you pronounce it, and where does it come from?" uses define: ontelbaar veel, IPA tɑxtin, a slip of the tongue from 2014, with sources.
  • "Rewrite this message with tachtien: 'Gisteren heel veel kopstootjes gedronken met ongeveer honderd man, en vandaag 3 aspirines.'" uses tachtienify: "Gisteren tachtien kopstootjes gedronken met tachtien man, en vandaag 3 aspirines." The exact 3 stays, because it was counted.
  • "I have more than 50 unread emails. Does that count as tachtien? And what about exactly 80?" uses is_tachtien: more than 50 is tachtien, because nobody counted; 80 is not, that is tachtig.
  • "Where has tachtien been mentioned in the press?" uses mentions with source: "press": four articles with links.

Tools

ToolInputReturns
definenonesyllables, part of speech, IPA, definition, origin
examplesrandom?: booleanexample dialogues, or one at random
mentions`source?: "twitter" \"press" \"cityguys"`external mentions with title, source and URL
tachtienifytext: stringtext with vague large amounts and estimates of 50 or more replaced by tachtien, the count, and each replaced phrase with its index
is_tachtien`amount: number \string`{ isTachtien, reason }

Estimates ("ongeveer honderd", "zo'n 60", "~200", "100+") and lower bounds ("meer dan 50", "ruim honderd") are tachtien from 50 up, because nobody counted them. Exact numbers, smaller estimates and years ("rond 2014") are not.

Prompts

PromptArgumentsWhat it does
uitleg`taal?: "Nederlands" \"English"`explains the word, with the entry embedded
herschrijftekst: stringruns tachtienify on the server, then asks the model to fix the grammar
zinonderwerp?: stringasks for a new example sentence in the style of the site

taal and onderwerp support completion/complete.

Resource tachtien://entry is the whole entry as Markdown. Content is Dutch, as on the site; tool descriptions are English.

curl -s https://mcp.tachtien.nl/mcp \
  -H 'content-type: application/json' -H 'accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"tachtienify","arguments":{"text":"heel veel kopstootjes"}}}'

Develop

npm install
npm run dev           # wrangler dev at http://localhost:8787 (MCP at /mcp)
npm test              # vitest in workerd
npm run check:drift   # compare src/entry.js with the live tachtien.nl
npm run deploy        # wrangler deploy to mcp.tachtien.nl

The first deploy creates the mcp.tachtien.nl DNS record and certificate, provided the tachtien.nl zone is in the same Cloudflare account.

Author

Made by Simon Vreeman.

Frequently asked questions

What is Tachtien?

Look up the Dutch word tachtien (uncountably many) and rewrite vague amounts as tachtien.

How do I install Tachtien?

It runs as a remote server. In Claude Code: claude mcp add --transport http tachtien 'https://mcp.tachtien.nl/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Tachtien need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Tachtien open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains Tachtien?

It is published by simonvreeman. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.