every-db-mcp — Multi-database MCP server for MySQL, GaussDB, Oracle and DM8

every-db-mcp is a Model Context Protocol (MCP) stdio server for database queries, table structure inspection, connection tests and explicitly enabled writes. MySQL uses Node.js/mysql2; GaussDB, Oracle and Dameng DM8 use Python subprocess bridges. It selects configured database IDs, not automatic project detection or SQL dialect inference.

Quick start

Requirements: Node.js 22+, npm and a reachable database. Python 3.10+ is needed for GaussDB, Oracle and DM8; MySQL does not need Python.

git clone https://github.com/vmayfuture/every-db-mcp.git
cd every-db-mcp
npm install

For Python-backed databases:

python -m pip install -r requirements.txt

Save this configuration as db-config.json in the project root, replacing placeholders with a dedicated account:

{
  "defaultDatabase": "mysql-dev",
  "defaultAllowInsert": false,
  "defaultAllowUpdate": false,
  "defaultAllowDelete": false,
  "defaultAllowDDL": false,
  "databases": [{
    "id": "mysql-dev",
    "type": "mysql",
    "host": "127.0.0.1",
    "port": 3306,
    "user": "readonly_user",
    "password": "replace-with-local-secret",
    "database": "app_dev",
    "allowInsert": false,
    "allowUpdate": false,
    "allowDelete": false,
    "allowDDL": false
  }]
}

npm run build
npm start

The stdio server waits for MCP requests. A client can launch it automatically; manual startup is only needed for a launch check. Configure Codex with your actual absolute paths:

[mcp_servers.every-db-mcp]
command = "node"
args = ["/absolute/path/to/every-db-mcp/dist/index.js"]
cwd = "/absolute/path/to/every-db-mcp"
enabled = true

Windows paths can use C:/tools/every-db-mcp/dist/index.js. The working directory matters: the loader looks for db-config.json there and does not read db-config.local.json. A set MYSQL_HOST replaces file connections with one MySQL connection named default; remove it for file-based multi-database use.

Full per-driver configurations, client JSON and troubleshooting: database guides. Detailed Chinese setup: README.md.

Use cases and calls

Use cases include development data inspection, schema understanding, troubleshooting missing records and comparing queries across configured environments. These sample prompts are not recorded execution results:

Use every-db-mcp to list configured connections. Test mysql-dev, then run
SELECT 1 AS mcp_probe with maxRows 5. Report the selected ID and connection result.

Inspect the orders table in gaussdb-dev and explain the columns.
Use only that connection; do not modify data.

Tool	Arguments	Purpose
`db_list_databases`	none	List configured connections
`db_test_connection`	`database?`	Test a connection
`db_query`	`sql`, `database?`, `maxRows?`	SELECT query
`db_get_table_structure`	`tableName`, `database?`	Inspect structure
`db_execute`	`sql`, `database?`	Permitted INSERT/UPDATE/DELETE/DDL

An agent can call db_test_connection with {"database":"mysql-dev"}, then db_query with {"database":"mysql-dev","sql":"SELECT 1 AS mcp_probe","maxRows":5}. Oracle/DM8 probes use SELECT 1 AS mcp_probe FROM DUAL.

Give connections unique environment-specific IDs and state the intended ID in project instructions. Omitting database selects defaultDatabase; it does not bind the current project automatically. Use the selected database's SQL dialect.

Permissions, FAQ and limits

Per-database allowInsert, allowUpdate, allowDelete and allowDDL control writes. Keep them explicitly false for read-only use and enforce privileges on the database account. SQL checks and limits do not replace database access control.

Why is file configuration ignored? Check the working directory and remove MYSQL_HOST when using the file's multiple connections.

What does Oracle schema mean? The bridge uses it as the service name in host:port/service, not as a table-owner selector.

Why does Python import fail? Set PYTHON_PATH to the interpreter containing the dependencies; it otherwise defaults to python. DM8 may need vendor runtime libraries.

Driver implementations do not prove every database version/platform compatible or establish successful live testing of all four drivers. Python bridges create connections per subprocess request; persistent pooling behavior differs from MySQL.

Development and license

npm run build compiles TypeScript. There is no automated test script. Test each actual target with a connection check and read-only query; this documentation does not claim new integration tests.

MIT license: LICENSE.