LSD MCP Server

LSD MCP server

Immediately gather an aggregation of high quality info directly from a website just by giving LSD the link via Claude MCP.

You will see Claude connect to the internet and:

• Write LSD SQL
• Self-correct LSD SQL
• Run LSD SQL that's connected to cloud browsers

Demo

Here's a demo of what that looks like in action:

We treated Claude to psychedelic therapy on LSD and now it can just do things. Here's a longer video on YouTube

Contents

• Quickstart
  • Dependencies
  • Giving Claude LSD
  • Claude on LSD
  • Failed to start MCP server
    • First time running an MCP server
    • Missing executable
    • Incomplete path
• What is MCP?
• What is LSD?
  • Contact
• Smithery
  • Installing via Smithery

Quickstart

Dependencies

To run the MCP server, you'll need both Python and uv installed. To use the MCP server, you'll need to download either the Claude desktop app or another MCP client.

To use LSD, you'll need to sign up and create an API key so your queries are privately associated to only your account. You can do so for free with a Google account.

Giving Claude LSD

1. Clone this repository onto your computer

$ git clone https://github.com/lsd-so/lsd-mcp.git
$ cd lsd-mcp

2. Update the values in the .env file with LSD_USER containing the email you have an account on LSD with and LSD_API_KEY containing the API key you obtained from the profile page.

LSD_USER=<your_email_here>
LSD_API_KEY=<api_key_from_your_profile_page>

3. Give LSD to Claude

$ uv run mcp install app.py

Note: Every time you run mcp install, if you needed to update claude_desktop_config.json the first time, you will need to remember to update the path to uv each time you install the MCP server.

4. Restart the Claude desktop app and, now, Claude should be able to do trippy things on LSD.

Claude on LSD

If it's the first time in a chat session where you'd like to have Claude use LSD, because we're not popular enough to get caught in Anthropic's crawls, you'll need to first leverage our custom prompt which feeds in our documentation as part of the assistance.

See the write_lsd_sql function if you're interested in how it works but it just boils down to a convenient rule we added to our SCAN keyword enabling a developer or LLM to retrieve the documentation for our language in markdown (if you'd like to run it yourself).

SCAN https://lsd.so/docs/database/language

Failed to start MCP server

If you encounter error messages when starting Claude desktop along the lines of the following message:

Failed to start MCP server: Could not start MCP server LSD: Error: spawn uv ENOENT

First time running an MCP server

If this is your first time using an MCP server on your computer than, to remedy the error shown above, follow the instructions under the Add the Filesystem MCP Server step to create a claude_desktop_config.json file that Claude desktop can know to refer to.

Missing executable

Additionally, if you've never done anything relating to Postgres on your computer, then you may encounter an error message containing something like the following:

Error: pg_config executable not found.

To fix, simply install postgres to your machine using an available package manager. If you're on a Mac, you can do so using brew.

$ brew install postgres

Incomplete path

Otherwise and maybe in addition to the issue shown above, in the location where claude_desktop_config.json is stored (is ~/Library/Application Support/Claude/claude_desktop_config.json if you're running on a Mac), modify the value of the command key under mcpServers -> LSD to contain the full path to running uv (run which uv in your terminal if you don't already know what it is).

{
  "mcpServers": {
    "LSD": {
-      "command": "uv",
+      "command": "/Users/your_mac_name/.local/bin/uv",
      "args": [
        "run",
        "--with",
        "mcp[cli]",
        "--with",
        "psycopg2-binary",
        "mcp",
        "run",
        "/Users/y/testing-mcp/lsd-mcp/app.py"
      ]
    }
  }
}

Once you've done that, restart Claude desktop and the problem should be resolved. If not, please file an issue.

What is MCP?

MCP, short for model context protocol, provides a communication layer between Claude and computer-accessible interfaces such as the filesystem or web APIs. If a limiting factor of LLMs was its detachment from the "real world" since it's just a text generating model, MCP allows users and developers to bring Claude to life.

What is LSD?

LSD SQL, a DSL for the web, enables developers to connect the internet to your applications as though it were a postgres compatible database. Rather than present a new semantic web ontology or make a new internet, it provides a dynamic declarative language that sits atop the existing one.

Designed to target browsers instead of an architecture, LSD allows for powerful parallelization while preserving simplicity with just-in-time tables meaning you can just get data without running a CREATE TABLE beforehand. Sign up for free with a Google account to start querying the internet!

Here's an example of something you can do with LSD, takes ~30 sec if first run

Contact

Reach out to pranav at lsd dot so if you have any questions.

Smithery

Installing via Smithery

To install LSD MCP Server for Claude Desktop automatically via Smithery:

npx -y @smithery/cli install @lsd-so/lsd-mcp --client claude