Oracle MCP Server

A Model Context Protocol (MCP) server for Oracle with two layers:

• generic Oracle query/introspection tools

• a backend-owned Lab control-plane mirror that reproduces the Notion Lab dispatch/return loop on Oracle tables

Features

• Execute SQL queries with parameter binding

• List tables across multiple schemas or filter by specific schema

• Describe table structures with multi-schema support

• View indexes and constraints across schemas

• Check Lab control-plane gates and build dispatch packets from backend state

• Stamp dispatch consumption, ingest execution returns, and create writers-room scene items

• Bootstrap the same Lab mirror on Oracle or PostgreSQL using the included DDL

• Multiple Oracle authentication methods

• Automatic parameter conversion (PostgreSQL style to Oracle)

• SQL injection prevention via bind variables

• Audit logging for security monitoring

Related MCP server: MariaDB Reader MCP Server

Installation

npm install

Configuration

Environment Variables

Create a .env file with your Oracle connection details. Choose one of these methods:

Method 1: Easy Connect String

ORACLE_CONNECTION_STRING=hostname:1521/service_name
ORACLE_USER=your_username
ORACLE_PASSWORD=your_password

Method 2: TNS Name

ORACLE_TNS_NAME=ORCL
ORACLE_USER=your_username
ORACLE_PASSWORD=your_password

Method 3: Individual Components

ORACLE_HOST=localhost
ORACLE_PORT=1521
ORACLE_SERVICE_NAME=ORCL  # or ORACLE_SID=ORCL
ORACLE_USER=your_username
ORACLE_PASSWORD=your_password

Optional settings:

ORACLE_DEFAULT_SCHEMA=HR  # Default schema if different from user

Usage with Claude Desktop

Add to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "oracle": {
      "command": "node",
      "args": ["/path/to/oracle-mcp/src/index.js"],
      "env": {
        "ORACLE_CONNECTION_STRING": "hostname:1521/service_name",
        "ORACLE_USER": "your_username",
        "ORACLE_PASSWORD": "your_password"
      }
    }
  }
}

Alternatively, use npx if you publish the package:

{
  "mcpServers": {
    "oracle": {
      "command": "npx",
      "args": ["-y", "oracle-mcp-server"],
      "env": {
        "ORACLE_CONNECTION_STRING": "hostname:1521/service_name",
        "ORACLE_USER": "your_username",
        "ORACLE_PASSWORD": "your_password"
      }
    }
  }
}

Usage with Claude Code

For Claude Code, add to ~/.claude.json:

{
  "mcpServers": {
    "oracle": {
      "type": "stdio",
      "command": "node",
      "args": ["/path/to/oracle-mcp/src/index.js"],
      "env": {
        "ORACLE_CONNECTION_STRING": "hostname:1521/service_name",
        "ORACLE_USER": "your_username",
        "ORACLE_PASSWORD": "your_password"
      }
    }
  }
}

After updating the configuration, restart Claude Desktop or Claude Code.

Available Tools

1. execute_query - Execute any SQL query

   • Supports parameter binding

   • Auto-converts PostgreSQL-style parameters ($1) to Oracle (:1)

   • Returns rows, rowCount, and metadata

2. list_tables - List database tables

   • Filter by specific schema or show all accessible schemas

   • Filter by pattern (with % wildcards)

   • Shows schema name, table name, row count, and last analyzed date

3. describe_table - Get table structure

   • Column names, types, sizes

   • Nullable constraints

   • Default values

   • Works across all accessible schemas or filter by specific schema

4. get_table_indexes - View table indexes

   • Index types and uniqueness

   • Indexed columns

   • Status information

   • Shows schema name for each index

5. get_table_constraints - View table constraints

   • Primary keys, foreign keys

   • Unique and check constraints

   • Referenced tables

   • Shows schema name for each constraint

6. list_schemas - List all accessible schemas

7. check_gates - Read lab_control + lab_work_items and enforce Pre-Flight / cascade-depth gates

8. get_dispatchable_items - List backend-owned Lab work items ready for dispatch

9. build_dispatch_packet - Validate a work item and produce an execution packet

10. stamp_dispatch_consumed - Accept ownership of a dispatch run

11. fail_dispatch_preflight - Revert a failed preflight and restore a dispatch-ready state

12. handle_final_return - Ingest a structured execution result into backend state

13. dispatch_scene - Create a writers-room scene item and fire its entry signal

Lab Mirror Bootstrap

Oracle DDL:

sqlplus user/password@db @sql/oracle/lab_control_plane.sql

PostgreSQL DDL:

psql "$DATABASE_URL" -f sql/postgres/lab_control_plane.sql

The mirror includes:

• lab_projects

• lab_work_items

• lab_control

• lab_agent_registry

• lab_scene_items

• lab_domain_events

• lab_outbox_events

• notion_projection_state

• lab_audit_log

• lab_telemetry

• lab_evidence_dossier

See docs/lab-backend-mirror.md for the backend ownership model and event flow.

Security

• All queries use bind variables to prevent SQL injection

• Connections are created per-query (no persistent pools)

• Comprehensive audit logging with timestamps and duration

• Environment variables keep credentials secure

• Supports both read-only and read-write operations

Requirements

• Node.js 18+

• Oracle Database (any version)

• Network access to Oracle database

License

MIT