MCP Server for Oracle

A Model Context Protocol server that provides access to Oracle databases with fine-grained access control. Supports multiple databases, access modes, and table-level permissions.

Features

Multi-database support: Connect to multiple Oracle databases simultaneously
Access control: readonly, readwrite, full modes per database
Table-level permissions: Whitelist/blacklist with wildcards and regex
Read-only transaction protection: Database-level safety for readonly mode
Backward compatible: Works with single database environment variables

Components

Tools

Tool	Description
`oracle_query`	Read-only SELECT queries (always available)
`oracle_execute`	Write operations (only visible when writable databases exist)

Resources

oracle://connections: List of database connections with access modes
oracle://{db}/tables/{table}/schema: Table schema

Prompts

oracle_usage_guide: Dynamic guide based on configured databases

Configuration

Config File

Create ~/.mcp_oracle/databases.json:

{
  "databases": [
    {
      "name": "prod",
      "user": "...",
      "password": "...",
      "connectString": "...",
      "accessMode": "readonly"
    },
    {
      "name": "dev",
      "user": "...",
      "password": "...",
      "connectString": "...",
      "accessMode": "readwrite",
      "allowedTables": ["LOG_*", "TMP_*", "/^TEST_.*/"]
    }
  ]
}

Access Modes

Mode	SELECT	INSERT/UPDATE/DELETE	DDL
`readonly` (default)	✅	❌	❌
`readwrite`	✅	✅	❌
`full`	✅	✅	✅

Table Patterns

Format	Example	Matches
Exact	`LOG_TABLE`	Only `LOG_TABLE`
Wildcard	`LOG_*`	`LOG_` prefix
Regex	`/^TEST_\d+$/`	`TEST_` + digits

Environment Variables

Variable	Description
`ORACLE_CONFIG_PATH`	Custom config file path
`ORACLE_USER`	Legacy single-database user
`ORACLE_PASS`	Legacy single-database password
`ORACLE_CONNECTION_STRING`	Legacy connection string
`ORACLE_HOME`	Oracle client library path
`TNS_ADMIN`	TNS admin directory

Usage Example

User: "查询 prod 库中的用户表"
→ oracle_query(database="prod", sql="SELECT * FROM users")

User: "在 dev 库的 LOG_TEST 表插入一条记录"
→ oracle_execute(database="dev", sql="INSERT INTO LOG_TEST ...", confirm=true)

Security

readonly mode: Uses SET TRANSACTION READ ONLY for database-level protection
SQL validation: Validates statement type before execution
Table validation: Checks whitelist/blacklist before write operations
Confirmation required: Write operations require confirm=true

License

MIT License