🛠️ MCP Server with C# + Firebird

This project is an MCP ( Model Context Protocol ) server created in C#, with support for custom tools. One of the features included is the execution of dynamic queries in a Firebird database with filter and record limit.

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📦 Technologies Used

• NPX
• C# (.NET 9)
• MCP ( Model Context Protocol )
• FirebirdSql.Data.FirebirdClient
• Dependency Injection via Host.CreateApplicationBuilder
• Configuration via appsettings.json

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⚙️ Configuration

Install dependencies by nuget

dotnet add package ModelContextProtocol --prerelease

🔧 appsettings.json File

Create an appsettings.json file in the project root with the following content:

{
"ConnectionStrings": {
"FirebirdDb": "Database=C:\\yourdata.fdb;User=SYSDBA;Password=masterkey;Dialect=3;Charset=NONE;" }
}

📝 Change the path of the .FDB file according to the location of your database.

📂 Recommended Project Structure

src/
├── MCPServer/
│ ├── Factory/
│ │ └── FbConnectionFactory.cs
│ ├── Tools/
│ │ └── FbQueries.cs
│ ├── Program.cs
│ └── appsettings.json

🧩 MCP Tool Available

🔍 ListTable

[McpTool, Description("List all records from a Firebird table")]
public List> ListTable(string tableName, string filter = "", int limitRecords = 0)

This tool returns records from a Firebird database table with:

🔎 Conditional filter via SQL

🔢 Limitation of number of records (using FIRST)

Example of use:

{
  "tool": "ListTable",
  "args": {
    "tableName": "CUSTOMERS",
    "filter": "STATUS = 'ACTIVE'",
    "limitRecords": 10
  }
}

Run MCP server

npx @modelcontextprotocol/inspector dotnet run