SQL Anywhere MCP Server (read-only)

An MCP server that lets Claude read a SAP SQL Anywhere database and answer questions in plain language — no SQL by hand.

Example: ask "how many customers do we have in Lombardy?" and Claude writes and runs the query for you.

Read-only by design. It can only run SELECT queries — it cannot insert, update, delete, or alter anything. See Security.

Requirements

• Python 3.10+
• The SQL Anywhere ODBC driver and a configured DSN for your database
• A dedicated, read-only database user (this project never creates users or changes permissions)
• Claude Code or Claude Desktop

Install

git clone https://github.com/TeoDreams/sqlanywhere-mcp-server.git
cd sqlanywhere-mcp-server
pip install -r requirements.txt

Configure

Set four values via a .env file or environment variables.

.env file (copy the template, then edit — it is gitignored):

cp .env.example .env

SQLANY_DSN=YOUR_DSN
SQLANY_UID=readonly_user
SQLANY_PWD=your_password
SQLANY_MAX_ROWS=200
SQLANY_QUERY_TIMEOUT=30

Or environment variables:

# Windows (PowerShell)
[Environment]::SetEnvironmentVariable("SQLANY_DSN", "YOUR_DSN", "User")
[Environment]::SetEnvironmentVariable("SQLANY_UID", "readonly_user", "User")
[Environment]::SetEnvironmentVariable("SQLANY_PWD", "your_password", "User")

# Linux / macOS
export SQLANY_DSN=YOUR_DSN
export SQLANY_UID=readonly_user
export SQLANY_PWD=your_password

Add to Claude

Claude Code — pick a scope:

# Global: available in all your projects
claude mcp add --scope user sqlanywhere-readonly -- python /path/to/sqlanywhere_mcp_server.py

# Project: only this repo, shared with the team via a committed .mcp.json
claude mcp add --scope project sqlanywhere-readonly -- python /path/to/sqlanywhere_mcp_server.py

claude mcp list

The default scope (local, if you omit --scope) registers the server only for you in the current project. Credentials stay out of a committed .mcp.json because they come from your environment variables / .env, not the command.

Claude Desktop — add this to the config file (%APPDATA%\Claude\claude_desktop_config.json on Windows, ~/Library/Application Support/Claude/claude_desktop_config.json on macOS, ~/.config/Claude/claude_desktop_config.json on Linux), then restart the app:

{
  "mcpServers": {
    "sqlanywhere-readonly": {
      "command": "python",
      "args": ["/path/to/sqlanywhere_mcp_server.py"]
    }
  }
}

Usage

Ask Claude things like:

• "Describe the structure of the customers table"
• "Show me the first rows of the products table"
• "How many orders were placed this month?"
• "Will this query use an index, or scan the whole table?"

Claude uses the two tools on its own:

Tool	What it does
list_tables	Lists table names (handy for large schemas)
describe_schema	Lists tables and columns (structure only, no data)
run_query	Runs a SELECT and returns the rows (up to the row cap)
explain_query	Shows the execution plan of a SELECT without running it

Security

• Only queries starting with SELECT run; write/DDL keywords (INSERT, UPDATE, DELETE, DROP, ALTER, etc.) are rejected before connecting.
• Returned rows are capped (default 200). This caps the response, not the query — the SELECT still runs in full on the server. A per-query timeout (SQLANY_QUERY_TIMEOUT, default 30s, 0 = no limit) aborts queries that run too long.
• Credentials come only from environment variables or .env, and are never printed in error messages.

Query plans

explain_query uses SQL Anywhere's EXPLANATION() function, which returns the optimizer's access plan without executing the query. (GRAPHICAL_PLAN() is deliberately not used — it can execute the statement to collect statistics.)

SQL Anywhere gates plan access behind a database option that is off by default. If explain_query reports that plans are unavailable, a DBA must enable it for your read-only user:

SET OPTION readonly_user.QUERY_PLAN_TEXT_ACCESS = ON;

Troubleshooting

If describe_schema returns nothing, your SQL Anywhere version may expose the schema through SYS.SYSTAB / SYS.SYSTABCOL instead of the SYS.SYSTABLE / SYS.SYSCOLUMN views used here — adjust the query in describe_schema accordingly.

License

MIT