Langdogu

This site in

Get Lingua Layer

Open to every assistant and server you choose

What you learn should not be stuck inside one app. Langdogu is being built so the assistant you already talk to can open your vocabulary, so you can run all of it on your own server, and so you can take your record with you at any time.

Talk about what you learned today In development

Add Langdogu to Claude or ChatGPT, then ask what you learned today. The assistant answers from your own saved expressions and the sentences you met them in, not from a textbook.

MCP is an open standard that lets an AI assistant use tools from another app. Langdogu is building an MCP server: a small set of tools that open your vocabulary, and nothing more.

Over MCPIn developmentSample

Talk to
  1. You

    What did I learn today?

  2. Used Langdogu: learning summary for today

  3. Claude

    You saved 3 expressions today, from a train notice and a manga chapter. 空気を読む is still in review. Want to practise it next to 本を読む, which you already know?

  4. You

    Let’s practise 空気を読む. And keep this sentence: 空気を読んで、静かに席を立った。

  5. Used Langdogu: save an expression

  6. Claude

    Saved 空気を読む with your sentence. It will come back in your reviews.

This is a planned exchange, not a released feature. Connections from claude.ai and chatgpt.com are not yet verified.

What each permission allows

Assistants get a few tools, never your database. You grant reading and writing one by one when you connect.

Read

The assistant can look at what you saved and how you are doing.

  • Search your saved expressions
  • Open one expression: its meaning, the sentence where you met it, and where it came from
  • A learning summary for today or this week
  • The reviews that are due

Write

The assistant can add to your record in exactly one way.

  • Save an expression

It cannot change or delete anything.

Never

  • Direct access to the database
  • Other people’s accounts
  • Your password or sign-in tokens
  • Payment details

Run it on your own server In development

Self-hosting is supported, and it is free forever. It is still in development, so there is no download and no guide yet.

Where
Your own PC, NAS or server.
What you get
The same learning features, the same API and the same MCP server as the Langdogu cloud.
How it runs
It is being built to run with Docker Compose.
AI
Bring your own AI key and pay your provider directly. Your own budget takes the place of Langdogu billing.
Price
Free forever. That is the software: AI is never free, and with your own key Langdogu adds no fee.

Same server, two homes

SampleIn development
Langdogu cloud
https://<langdogu cloud>/mcp
Your server
https://<your server>/mcp
Your assistant connects to /mcp on whichever one holds your record.

Planned pricing

Take your record with you Planned

Your data is yours. You should be able to export all of it at any time, in open formats.

Full JSON backup

Keeps everything in your record.

Anki file (TSV)

Your expressions with the sentences you met them in.

Two expressions as one Anki file might hold themSample
空気を読む空気を読んで、静かに席を立った。
発車2番線の快速電車は、まもなく発車します。

One record, every door

Lingua Layer, the app, AI assistants and self-hosted installs are meant to be doors into one record of what you know, served by one shared API.

One record behind every doorIntent

An open core Intent

The intent is to open-source the core, together with Anki import and export. Langdogu plans to earn from the managed cloud and from usage-based AI.

See the planned pricing

Want to hear when it opens?

There is no waitlist form. Write to [email protected], with questions too.

Write to [email protected]