Argos-MCP

A hundred eyes on your databases, and none of them blink.

Argos Panoptes (Ἄργος Πανόπτης) is the giant of Greek myth with a hundred eyes, set by Hera to guard Io. Only some of his eyes slept at a time, so he was never fully asleep and nothing passed him unseen. Panoptes means "all-seeing".

Argos-MCP connects Claude Code to PostgreSQL, MySQL, SQLite, and SQL Server with strong security defaults, per-query auditing, and multi-database support. Every query is watched, and nothing reaches your data unlogged.

Status: pre-release. Argos-MCP is not yet published to npm, and the publish step in the release workflow is deliberately dormant. The source is public on GitHub, so install from source (see Quick start). Any npm install -g argos-mcp command you find elsewhere will not resolve yet.

Why Argos-MCP?

Security First

• SELECT-Only Mode - Production-safe read-only database access

• Query Validation - Bound parameters, stacked statements refused, comment- and literal-aware parsing, complexity limits

• SSH Tunneling - Secure encrypted connections through bastion hosts

• Audit Logging - One record per query: database, statement hash, duration, outcome, never the values

High Performance

• Connection Pooling - Efficient database connection management

• Schema Caching - Captured once per database, reused for the session

• Query Optimization - Built-in performance analysis and recommendations

• Batch Operations - Execute multiple queries with transaction support

Universal Database Support

• PostgreSQL - Full support including advanced features

• MySQL/MariaDB - Via mysql2, including Azure Database for MySQL/MariaDB

• SQLite - Perfect for development and small applications

• SQL Server - Enterprise-grade Microsoft SQL Server support, including Azure SQL with passwordless sign-in through the Azure CLI

Developer Experience

• One-command install - Registers with Claude Code via the native claude mcp add

• TypeScript Native - Full type safety and IntelliSense support

• Comprehensive Docs - Detailed guides, tutorials, and API reference

• Extensive Testing - Unit and integration suites, plus mutation testing on the security-critical paths

Related MCP server: MCP Database Server

Quick start

Requirements: Node.js >= 22 and the Claude Code CLI. Connecting to Azure SQL with authentication=azure-cli additionally needs the Azure CLI on PATH and a completed az login; nothing else does.

1. Build

git clone https://github.com/AraneaDev/Argos-MCP.git
cd Argos-MCP
npm install
npm run build

2. Configure databases

npm run setup

Interactive wizard for adding database connections, security settings, and SSH tunnels. It writes a config.ini, by convention at ~/.config/argos/config.ini, though any path works. You can also add databases at runtime with the sql_add_database tool.

3. Register with Claude Code

claude mcp add argos --scope user -- \
  node "$(pwd)/dist/index.js" --config "$HOME/.config/argos/config.ini"

Scopes:

4. Verify

claude mcp list

You should see argos listed as connected. Its tools appear in Claude Code as mcp__argos__sql_query, mcp__argos__sql_get_schema, and so on.

Removing it

claude mcp remove argos --scope user

Use cases

Data Analytics & Business Intelligence

"Show me the top 10 customers by revenue this quarter, including their growth rate compared to last quarter"

Production Database Monitoring

"Check the status of our user registration system - how many signups in the last 24 hours and any error patterns?"

Database Administration

"Analyze the performance of our product catalog queries and suggest optimizations"

Development & Testing

"Generate test data scenarios based on our current user demographics"

Architecture

graph TB
 Claude[Claude Code] --> MCP[MCP Protocol]
 MCP --> Security[Security Layer]
 Security --> Connection[Connection Manager]
 Connection --> Adapters[Database Adapters]

 Adapters --> PostgreSQL[(PostgreSQL)]
 Adapters --> MySQL[(MySQL)]
 Adapters --> SQLite[(SQLite)]
 Adapters --> MSSQL[(SQL Server)]

 Security --> SSH[SSH Tunneling]
 SSH --> Bastion[Bastion Host]
 Bastion --> RemoteDB[(Remote Database)]

Built on solid foundations:

• TypeScript - Full type safety and modern development experience

• Node.js - Cross-platform compatibility and excellent ecosystem

• MCP Protocol - Standard protocol for AI tool integration

• Industry-standard drivers - Proven database connectivity libraries

Documentation hub

Getting Started

• 5-Minute Quick Start - Get running fast

• Installation Guide - Detailed setup instructions

• First Database Tutorial - Connect your first database

• Claude Integration - Register with Claude Code

Architecture & Design

• System Architecture - How it all works together

• Security Architecture - Defense-in-depth security model

• Database Layer - Adapter pattern implementation

API Reference

• MCP Tools Reference - Complete tool documentation

• TypeScript API - Developer API reference

• Configuration Reference - All configuration options

Advanced Guides

• Multi-Database Setup - Managing multiple databases

• SSH Tunneling - Secure remote access

• Security Hardening - Production security guide

• Performance Tuning - Optimization strategies

Browse All Documentation

Configuration examples

Production PostgreSQL with SSH

[database.production]
type=postgresql
host=internal-db.company.local
port=5432
database=production_app
username=readonly_user
password=secure_random_password
ssl=true
select_only=true
timeout=15000

# SSH Tunnel Configuration
ssh_host=bastion.company.com
ssh_port=22
ssh_username=tunnel_user
ssh_private_key=/secure/path/ssh_key
# Required: without a pinned fingerprint the tunnel refuses to connect, rather
# than trusting whatever host key it is offered. Get it from the bastion with
#   ssh-keygen -lf /etc/ssh/ssh_host_ed25519_key.pub
ssh_host_fingerprint=SHA256:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU

[security]
max_joins=5
max_subqueries=3
max_complexity_score=50

Azure SQL without a password

The Azure CLI's own sign-in is the credential, so no secret is written to config.ini at all.

[database.azure_sql]
type=mssql
host=your-server.database.windows.net
port=1433
database=your_database_name
authentication=azure-cli
select_only=true

# Only when the server's tenant is not the CLI's active context, which is the
# usual case for an account with access to several tenants. Must be the GUID.
# azure_tenant_id=00000000-0000-0000-0000-000000000000

Needs az login beforehand, and the signed-in identity mapped as a database user: CREATE USER [you@company.com] FROM EXTERNAL PROVIDER;. Encryption and certificate verification are forced on for this mode, because an access token is a bearer credential and an unverified connection hands it to whoever answers.

See the SQL Server guide for the details, including unattended use.

Multi-Database Analytics Setup

[database.transactions]
type=postgresql
host=transactions-db.company.com
database=transactions
select_only=true

[database.users]
type=mysql
host=users-db.company.com
database=users
select_only=true

[database.analytics]
type=sqlite
file=./data/analytics.sqlite
select_only=false

[database.local_cache]
type=sqlite
file=./data/cache.sqlite
select_only=false
mcp_configurable=true

[extension]
max_rows=1000
query_timeout=30000

Security features

Multi-Layer Security Model

1. Query Validation - SQL injection prevention and syntax analysis

2. Complexity Limits - Prevent resource-intensive queries

3. SELECT-Only Mode - Read-only database access for production safety

4. Connection Encryption - SSL/TLS and SSH tunnel support

5. Audit Logging - Comprehensive security event tracking

6. Field Redaction - Automatic masking of sensitive data in query results

Field Redaction

Automatically mask, replace, or partially obscure sensitive fields (emails, phone numbers, SSNs, etc.) in query results before they reach Claude or other clients. Redaction is configured per-database in config.ini:

[database.production]
type=postgresql
host=prod-db.company.com
database=app_db
username=readonly_user
password=secure_pass
select_only=true

# Field Redaction
redaction_enabled=true
redaction_rules=*email*:partial_mask,*phone*:full_mask,ssn:replace:[PROTECTED]
redaction_case_sensitive=false
redaction_log_access=true

Redaction types:

Field patterns: exact match (email), wildcard (*email*), or regex (/^user_.+$/).

Full Redaction Guide

What this gives you towards compliance

Argos is not certified against any standard, and no library can be. Compliance is a property of your deployment. What it provides is the controls and the evidence that such a regime asks for:

• Read-only enforcement that cannot be relaxed from a session

• Field redaction, so protected columns never reach the model

• An audit record per query: timestamp, database, statement hash, duration, outcome, with no values and no SQL

• Secrets scrubbed from logs and error messages

• Owner-only file modes on the log, the audit records and the configuration

Dynamic database management

Argos-MCP supports runtime database management through dedicated MCP tools. This allows you to add, update, and remove database connections without restarting the server.

Available MCP Tools

Usage Notes

• Set mcp_configurable=true in your database config to allow MCP-driven updates and removal.

• The sql_set_mcp_configurable tool is a one-way lock: once set to false, the database can no longer be modified or removed via MCP. Unlocking requires a manual edit to the configuration file.

• The sql_get_config tool always redacts passwords and other sensitive fields before returning configuration data.

• Databases added at runtime via sql_add_database have mcp_configurable=true by default, and are always select_only=true. Granting write access requires editing config.ini by hand, so the model cannot grant it to itself.

Performance

Query time is your database's, not Argos's. It adds validation and formatting around a normal client connection. sql_get_metrics reports the latency it actually observed (min, max, avg, p95), and sql_analyze_performance returns the execution plan with dialect-specific advice when something is slow.

Performance Features

• Connection Pooling - Reuse database connections efficiently

• Schema Caching - Instant metadata access after initial capture

• Query Optimization - Built-in EXPLAIN plan analysis

• Result Streaming - Handle large datasets efficiently

• Batch Operations - Execute multiple queries optimally

CLI commands

Both are exposed as bin entries, so npm link (or a global install) makes them available on your PATH. Registration with Claude Code is handled by claude mcp add, see Quick start.

Development

Development Setup

git clone https://github.com/AraneaDev/Argos-MCP.git
cd Argos-MCP
npm install
npm run dev
npm test

Full Development Guide

Layers

The source is layered, and a lower layer may never depend on a higher one:

Nothing in src imports from tests or examples.

These rules are not enforced by CI. They are a design constraint, checked by hand or by whatever analysis tool you point at the checkout, so read the table before adding an import that reaches upward. A cycle between layers is the signal that something belongs in a lower one.

License

Released under the MIT License, free for any use, commercial included, with no warranty. It speaks any MCP client, not just Claude Code, and connects to databases you already run.

Acknowledgments

Built With

• TypeScript - Language and tooling

• Node.js - Runtime platform

• Jest - Testing framework

• ESLint - Code quality

• MCP Protocol - AI integration standard

Special Thanks

• Anthropic - For Claude AI and MCP protocol

• TypeScript Team - For excellent tooling

• Database Driver Maintainers - For reliable connectivity libraries

Get Started Now | Documentation

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