Grain SQL

Name: Grain SQL
Author: pattrnlabs

by pattrnlabsversion 0.10.49i★ –iRuns on your computer

Registry nameio.github.pattrnlabs/grain

Install

Overview

Description from the maker (original English)

Run SQL queries and inspect database schemas through safe, visible MCP tools.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Databases & datasets
You need to fill in: GRAIN_CONNECTIONS

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: GRAIN_CONNECTIONS, GRAIN_MCP_SAFE_MODE, GRAIN_MAX_ROWS

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "grain": {
      "command": "npx",
      "args": [
        "-y",
        "grain-tools"
      ],
      "env": {
        "GRAIN_CONNECTIONS": "your-value",
        "GRAIN_MCP_SAFE_MODE": "your-value",
        "GRAIN_MAX_ROWS": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add grain --env GRAIN_CONNECTIONS=your-value --env GRAIN_MCP_SAFE_MODE=your-value --env GRAIN_MAX_ROWS=your-value -- npx -y grain-tools

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "grain": {
      "command": "npx",
      "args": [
        "-y",
        "grain-tools"
      ],
      "env": {
        "GRAIN_CONNECTIONS": "your-value",
        "GRAIN_MCP_SAFE_MODE": "your-value",
        "GRAIN_MAX_ROWS": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "grain": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "grain-tools"
      ],
      "env": {
        "GRAIN_CONNECTIONS": "your-value",
        "GRAIN_MCP_SAFE_MODE": "your-value",
        "GRAIN_MAX_ROWS": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

GRAIN_CONNECTIONS secret env
JSON array of Grain connection profiles for headless use.
GRAIN_MCP_SAFE_MODE env
Set to false to allow mutating SQL. Defaults to true.
GRAIN_MAX_ROWS env
Maximum rows returned by query tools. Defaults to 10000.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account pattrnlabs, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Databases & datasetsi

More stars than 0% of the other 1139 servers in this category
Published to the registry more recently than 93% of the other 1139 servers in this category
Basic checks equal to or better than 100% of the other 1139 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Grain SQL safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: GRAIN_CONNECTIONS

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.10.49) reached the registry 3 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Supabase, MongoDB MCP Server, Elasticsearch MCP Server

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Grain

A fast SQL workspace for VS Code, and for the AI agents you work with.

Docs · Changelog · Report a bug · Ask a question

Run SQL from any .sql file with Ctrl+Enter and get the results in a sortable grid inside VS Code. Passwords stay in your OS keychain, and Grain has no hosted service.

Quick start

Install Grain from the VS Code Marketplace or Open VSX (for Cursor, Windsurf, and VSCodium).
Open a folder in VS Code. Grain adds its demo files there.
Open the Grain panel and click Try the Demo.
Put your cursor in any query in the file that opens and press Ctrl+Enter (Cmd+Enter on macOS).

The demo reads two CSV files through Grain's built-in DuckDB connection, so there's nothing to set up. To query your own database, run Grain: Manage Connections, add a profile, and test it before you save.

If Grain is useful to you, a star on this repo helps other developers find it.

Use Grain from an AI agent

Grain can serve your database connections to Claude Code, Cursor, and GitHub Copilot over MCP. Agents get read-only access by default, and every query an agent runs shows up in your Grain results panel, so you can see exactly what it did.

MCP is off until you turn on grain.mcpEnabled in settings. Setup steps for each client are in the MCP docs, and example prompts are in examples/agents/.

Features

Feature	What it does
Run from the editor	`Ctrl+Enter` runs the file; Run Query Under Cursor runs one statement; Run Query in New Tab keeps the previous result
Non-blocking queries	Queries run in a background process, so a slow query doesn't freeze VS Code
Connection manager	Create, test, and switch database profiles without editing JSON
Result grid	Sort, filter, and resize columns, see each column's SQL type, copy a selection as TSV
Full export	The grid shows the first 500 rows; export re-runs the query and writes every row to CSV, TSV, or JSON
Agent access over MCP	Claude Code, Cursor, and Copilot can query your connections; their results land in your panel
Remote setups	Works over WSL, dev containers, GitHub Codespaces, and Remote - SSH

Supported databases

Relational databases

PostgreSQL

MySQL

SQL Server

SQLite

Data warehouses

Snowflake

BigQuery

Query engines & lakehouses

Trino / Presto

DuckDB

Elasticsearch

Through Trino or Presto you can query your cluster's Iceberg, Delta Lake, and Hive tables. DuckDB queries local CSV and Parquet files directly.

PostgreSQL and Trino / Presto are bundled with the extension. The others load their driver on first use, and if a driver is missing, Grain tells you what to install.

Need another database? Request a connector. Requests with the most 👍 get built first.

Examples

Runnable queries for Postgres, MySQL, Elasticsearch, and DuckDB, plus agent prompts. Open any .sql file with Grain installed and press Ctrl+Enter.

Privacy

Your SQL, results, and passwords stay on your machine. Passwords are stored in VS Code Secret Storage, backed by your OS keychain, and never in a settings file.
Agents are read-only by default. With grain.mcpSafeMode on (the default), agents can only run SELECT, SHOW, DESCRIBE, EXPLAIN, WITH, and metadata queries. Agents can't read stored passwords or change saved connections.
Telemetry is anonymous. Grain sends usage data that never includes SQL, results, credentials, hostnames, or schema names. Turn it off with grain.telemetry.enabled.

FAQ

Is Grain open source?\ No. Grain is closed-source. This repo holds the issue tracker, docs, and examples.

Which databases does it support?\ The nine listed above. To ask for another one, request a connector.

Do my queries or passwords leave my machine?\ No. There's no Grain server. Queries go straight from VS Code to your database, and passwords stay in your OS keychain. See Privacy for what the anonymous telemetry does and doesn't include.

How do I connect Claude Code or Cursor?\ Turn on grain.mcpEnabled, then follow the steps for your client in the MCP docs.

Why does my database show a driver error?\ Some connectors load their driver on first use. The error message names what to install. If it's still failing after that, file a bug report with the Output panel logs (View → Output → Grain).

Getting help

Bug: file a bug report
Feature idea: file a feature request
New database: request a connector
Question: check the FAQ and docs, then ask a question

We don't have a fixed roadmap yet. What we build next depends a lot on what people ask for here, especially connector requests. See CONTRIBUTING.md for how to file a good issue.

Star History

License

Grain is closed-source. See LICENSE.

Grain SQL

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Databases & datasetsi

Common questions

Alternatives

Supabase

MongoDB MCP Server

Elasticsearch MCP Server

README from the maker

Grain

Quick start

Use Grain from an AI agent

Features

Supported databases

Examples

Privacy

FAQ

Getting help

Star History

License