AdoMcp

AdoMcp

AdoMcp is a Model Context Protocol (MCP) server that helps large language models (LLMs) understand database structure, read table comments, and execute SQL queries.

AdoMcp 是一个基于 Model Context Protocol (MCP) 的数据库工具服务，帮助大型语言模型（LLM）理解数据库结构、读取表注释、执行 SQL 查询。

MCP Tools

Tool	Description
list_connections	List configured database connections
add_connection	Add (or replace) a database connection at runtime
remove_connection	Remove a dynamically-added connection
list_objects	List database objects (table/view/procedure/function/trigger/sequence/synonym, etc.)
get_table_schema	Get table schema details (columns/types/nullability/PK/default/comments)
get_table_indexes	Get table indexes
query_sql	Execute read-only SQL and return CSV
execute_sql	Execute write SQL (requires --allow-any-sql)

Recommended Tool Workflow (for LLM agents)

To reduce mistakes (wrong database/schema/object), use tools in this order:

1. list_connections to discover available connections.
2. If none are available, call add_connection.
3. Before inspecting a table/view, call list_objects to locate schema + objectType + objectName.
4. Use get_table_schema for column details (type, nullability, PK, default, comments).
5. Use get_table_indexes when index/key design matters.
6. Use query_sql only for read-only verification.
7. Use execute_sql only when explicitly authorized and server is started with --allow-any-sql.

Oracle note: objects without owner prefix may be synonyms. Always confirm the real schema via list_objects first.

Supported Databases

Database	Driver	Comment support
SQL Server	Microsoft.Data.SqlClient	MS_Description extended properties
MySQL / MariaDB	MySqlConnector	TABLE_COMMENT / COLUMN_COMMENT
PostgreSQL	Npgsql	obj_description / col_description
SQLite	Microsoft.Data.Sqlite	— (SQLite has no native comments)
Oracle	Oracle.ManagedDataAccess.Core	ALL_TAB_COMMENTS / ALL_COL_COMMENTS (includes PUBLIC synonyms)

ORM support: Dapper

Requirements

• .NET 10 SDK

---

Quick Start

1. Configure database connections (optional)

AdoMcp loads configuration from multiple sources (later sources override earlier ones):

1. appsettings.json (in the app directory)
2. appsettings.{Environment}.json
3. ~/.adomcp.json — user-level config (%USERPROFILE%\.adomcp.json on Windows), persists connections and AllowAnySql without touching the app directory
4. Environment variables prefixed ADOMCP_
5. .NET User Secrets

You can pre-configure connections in any of these. You can also skip this step entirely and let the LLM add connections dynamically via the add_connection tool.

{
  "AllowAnySql": false,
  "Databases": [
    {
      "Name": "mydb",
      "DbType": "SqlServer",
      "ConnectionString": "Server=localhost;Database=MyDb;User Id=sa;Password=***;TrustServerCertificate=true;",
      "Description": "Main business database"
    }
  ]
}

Supported DbType values: SqlServer | MySql | PostgreSql | Sqlite | Oracle

Security tip: Use .NET User Secrets or environment variables to manage connection strings in production.

User-level config example (~/.adomcp.json)

Create ~/.adomcp.json in your home directory to persist personal connections and settings across projects:

{
  "AllowAnySql": true,
  "Databases": [
    {
      "Name": "local-pg",
      "DbType": "PostgreSql",
      "ConnectionString": "Host=localhost;Database=dev;Username=postgres;Password=***;",
      "Description": "Local PostgreSQL dev DB"
    }
  ]
}

2. Run the server

Default mode

By default the server runs in stdio mode (the standard MCP transport for local clients). Use --http (or ADOMCP_MODE=http) to switch to HTTP/SSE mode.

# stdio mode (default) - all logs go to stderr; stdout carries only MCP JSON-RPC
dnx -y AdoMcp

Specify mode manually

# stdio mode (all logs go to stderr; stdout carries only MCP JSON-RPC)
dnx -y AdoMcp -- --stdio

# HTTP/SSE mode (default: http://localhost:5100, MCP endpoint /mcp)
dnx -y AdoMcp -- --http

# Via environment variable
ADOMCP_MODE=http 
dnx -y AdoMcp

Enable execute_sql (write operations)

By default the execute_sql tool is disabled to prevent unauthorised writes.
Enable it via CLI flag, config file, or environment variable (CLI flag wins when explicitly set):

# CLI flag
# Combine with transport mode
dnx -y AdoMcp -- --http --allow-any-sql

// ~/.adomcp.json or appsettings.json
{
  "AllowAnySql": true
}

# Environment variable
# ADOMCP_ALLOWANYSQL=true dnx -y AdoMcp

Priority: --allow-any-sql CLI > ADOMCP_ALLOWANYSQL env > ~/.adomcp.json AllowAnySql > appsettings.json AllowAnySql > false (default).

3. Alternative: Install as a global .NET tool

After the package is published to NuGet.org, you can also install it as a global tool:

dotnet tool install -g AdoMcp
adomcp

You can also run dnx directly (installs and runs on demand, .NET 10+):

dnx -y AdoMcp -- --allow-any-sql

---

Dynamic connections at runtime (no config file needed)

LLMs can add new database connections during a session using add_connection:

User: Connect me to Oracle database oradb01
LLM → calls add_connection(
    connectionString = "Data Source=oradb01:1521/PROD;User Id=appuser;Password=***;",
    dbType = "Oracle",
    name = "prod-oracle",
    description = "Production Oracle DB"
)
→ returns: Connection 'prod-oracle' (Oracle) added successfully.
LLM → calls list_objects(connectionName = "prod-oracle")

Dynamically-added connections exist only for the lifetime of the process; restart the server or add the connection to appsettings.json for persistence.

---

Client configuration

Via dnx (stdio)

{
  "mcpServers": {
    "adomcp": {
      "command": "dnx",
      "args": ["-y", "AdoMcp"]
    }
  }
}

Via HTTP/SSE

Start the server first:

dnx -y AdoMcp -- --http

Then configure the client:

{
  "mcpServers": {
    "adomcp": {
      "url": "http://localhost:5100/mcp"
    }
  }
}

---

Environment variables

All environment variables are prefixed with ADOMCP_ (override appsettings.json):

Variable	Description
ADOMCP_MODE	Transport mode: stdio or http (auto-detected when not set)
ADOMCP_URLS	HTTP listen address, e.g. http://0.0.0.0:5100
ADOMCP_ALLOWANYSQL	Enable the execute_sql tool: true or false (default false)
ADOMCP_DATABASES	JSON-encoded Databases array (overrides config-file connections)

---

MCP Registries

AdoMcp is registered in the official MCP Registry under the server name io.github.John0King/adomcp.