DataLink
MCP server for secure database access (PostgreSQL, MySQL, SQLite)
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).
@pilat/mcp-datalinkclaude mcp add datalink -e 'DATALINK_ANALYTICS_URL=<your datalink_analytics_url>' -e 'DATALINK_ANALYTICS_READONLY=<DATALINK_ANALYTICS_READONLY>' -- npx -y @pilat/mcp-datalink@1.2.4{
"mcpServers": {
"datalink": {
"command": "npx",
"args": [
"-y",
"@pilat/mcp-datalink@1.2.4"
],
"env": {
"DATALINK_ANALYTICS_URL": "<your datalink_analytics_url>",
"DATALINK_ANALYTICS_READONLY": "<DATALINK_ANALYTICS_READONLY>"
}
}
}
}Environment variables
DATALINK_ANALYTICS_URLrequired secret Database connection URL. Pattern: DATALINK_<NAME>_URL where <NAME> identifies the database. Supports postgresql://, mysql://, or file path for SQLite.DATALINK_ANALYTICS_READONLYSet to 'true' for read-only access. Pattern: DATALINK_<NAME>_READONLY
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
@pilat/mcp-datalink
MCP server for PostgreSQL, MySQL, and SQLite. Gives AI assistants secure database access via Model Context Protocol.
npx @pilat/mcp-datalinkWorks with Claude Desktop, Claude Code, Cursor, Cline, and any MCP-compatible client.
Installation
Add to your MCP client config file (see config locations below):
{
"mcpServers": {
"datalink": {
"command": "npx",
"args": ["-y", "@pilat/mcp-datalink"],
"env": {
"DATALINK_ANALYTICS_URL": "postgresql://user:password@localhost:5432/analytics",
"DATALINK_ANALYTICS_READONLY": "true",
"DATALINK_INVENTORY_URL": "mysql://user:password@localhost:3306/inventory",
"DATALINK_CACHE_URL": "sqlite:///path/to/cache.db"
}
}
}
}This creates three database connections: analytics (read-only), inventory, and cache.
| Variable | Description |
|---|---|
DATALINK_{NAME}_URL | Connection URL (creates database named {name}) |
DATALINK_{NAME}_READONLY | Set to true to block writes |
DATALINK_{NAME}_MAX_TIMEOUT | Max query timeout in ms (caps model requests) |
Connection URL formats:
# PostgreSQL
postgresql://user:password@localhost:5432/dbname
postgresql://user:password@localhost:5432/dbname?sslmode=require
# MySQL
mysql://user:password@localhost:3306/dbname
mysql://user:password@localhost:3306/dbname?ssl=true
# SQLite
sqlite:///path/to/database.db
sqlite:///Users/me/data/app.sqlite
sqlite://../relative/path/data.dbEnvironment Variable Substitution
URLs support ${VAR} syntax to reference other environment variables:
{
"mcpServers": {
"datalink": {
"command": "npx",
"args": ["-y", "@pilat/mcp-datalink"],
"env": {
"DATALINK_MAIN_URL": "${DATABASE_URL}"
}
}
}
}This allows reusing existing environment variables (like DATABASE_URL from your shell or .env file).
Supported syntax:
| Syntax | Description |
|---|---|
${VAR} | Expands to value of VAR, or keeps ${VAR} if unset |
${VAR:-default} | Expands to value of VAR, or default if unset |
Examples:
# Reference existing DATABASE_URL
DATALINK_MAIN_URL="${DATABASE_URL}"
# Build URL from parts
DATALINK_MAIN_URL="postgresql://${DB_USER}:${DB_PASS}@${DB_HOST}:5432/mydb"
# With default values
DATALINK_MAIN_URL="postgresql://localhost:${DB_PORT:-5432}/mydb"Config File Locations
| Client | Config file |
|---|---|
| Claude Code | ~/.claude.json (global) or .mcp.json (project) |
| Claude Desktop (macOS) | ~/Library/Application Support/Claude/claude_desktop_config.json |
| Claude Desktop (Windows) | %APPDATA%\Claude\claude_desktop_config.json |
| Cursor | ~/.cursor/mcp.json or Settings → Features → MCP Servers |
| Cline | cline_mcp_settings.json or VS Code settings cline.mcpServers |
Tools
| Tool | Description |
|---|---|
list_databases | List configured database connections |
list_tables | List tables with row counts |
describe_table | Get schema, indexes, foreign keys |
query | Run SELECT queries |
execute | Run INSERT/UPDATE/DELETE |
explain | Show query execution plans |
Security
- Prepared statements only (no SQL injection)
- Single statement per query (no chaining)
- DDL blocked (no DROP, ALTER, TRUNCATE)
- Readonly mode per connection
- Response size limit (100 rows, 64KB default, configurable via
DATALINK_MAX_TOTAL_SIZE) - Query timeout: 30s default, model can request up to 10min,
MAX_TIMEOUTcaps it
License
MIT
Frequently asked questions
What is DataLink?
MCP server for secure database access (PostgreSQL, MySQL, SQLite)
How do I install DataLink?
It runs on your machine. In Claude Code: claude mcp add datalink -e 'DATALINK_ANALYTICS_URL=<your datalink_analytics_url>' -e 'DATALINK_ANALYTICS_READONLY=<DATALINK_ANALYTICS_READONLY>' -- npx -y @pilat/mcp-datalink@1.2.4. For other clients, paste the JSON configuration from this page into their MCP settings.
Does DataLink need an API key?
Yes. It expects DATALINK_ANALYTICS_URL, which you set in its configuration.
Is DataLink open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains DataLink?
It is published by pilat. 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.