nxmcp - NexusDB MCP Server

An MCP (Model Context Protocol) server that enables AI assistants to interact with NexusDB databases. Built with Delphi, this server exposes NexusDB operations as MCP tools and resources.

Features

Query Execution - Run SELECT queries and retrieve results as JSON
Data Manipulation - Insert, update, and delete records
Schema Management - Create tables, add columns, manage indexes
Discovery - List tables, view schemas, get table structures, list indexes
Utility - Count records, show query execution plan

Requirements

Delphi (RAD Studio 13) with NexusDB Komponente
NexusDB NXserver running and accessible
https://github.com/GDKsoftware/Delphi-MCP-Server (may have additional depencies)
https://github.com/viniciussanchez/dataset-serialize
Windows OS

Configuration

Edit Source/nxconfig.ini and put it next to the executable before running:

[Connection]
ServerHost=localhost
ServerPort=16000

[Database]
AliasName=YourDatabaseAlias
TablePassword=optional_table_password

[Authentication]
Username=your_username
Password=your_password

[Options]
AutoConnect=1
Timeout=30000

Edit Source/settings.ini and put it next to the executable before running:

; for a detailed example check https://github.com/GDKsoftware/Delphi-MCP-Server
[Server]
Port=3000
Host=localhost
Name=nxmcp
Version=1.0.0
Endpoint=/mcp
; Server configuration=
[CORS]
Enabled=1
AllowedOrigins=http://localhost,http://127.0.0.1,https://localhost,https://127.0.0.1
; Comma-separated list of allowed origins=
; Cross-Origin Resource Sharing configuration=
[SSL]
Enabled=0
CertFile=
KeyFile=
RootCertFile=

Building

Open Source/nxmcp.dpr in Delphi
Ensure NexusDB components and the MCP library are in your search path
Build the project (Ctrl+F9)

Running

nxmcp.exe

The server starts on http://localhost:3000/mcp by default.

Available Tools

Query & Discovery

Tool	Description	Parameters
`execute_query`	Run SELECT queries	`sql`
`get_table_schema`	Get table structure	`tableName`

Data Manipulation

Tool	Description	Parameters
`get_table_data`	Read table data with pagination	`tableName`, `maxRows?`, `offset?`, `orderBy?`
`insert_record`	Insert a new record	`tableName`, `data` (JSON string)
`update_records`	Update matching records	`tableName`, `data` (JSON string), `whereClause`
`delete_records`	Delete matching records	`tableName`, `whereClause`
`execute_sql`	Run INSERT/UPDATE/DELETE	`sql`

Schema Management

Tool	Description	Parameters
`create_table`	Create a new table	`tableName`, `columns` (JSON array)
`drop_table`	Delete a table	`tableName`
`copy_table`	Clone a table	`sourceTable`, `targetTable`, `copyData?`
`rename_table`	Rename a table	`oldName`, `newName`
`add_column`	Add a column	`tableName`, `columnName`, `columnType`, `size?`, `defaultValueType?`
`drop_column`	Remove a column	`tableName`, `columnName`
`modify_column`	Modify a column	`tableName`, `columnName`, `newType?`, `newSize?`, `newName?`
`create_index`	Create an index	`tableName`, `indexName`, `columns`, `unique?`
`drop_index`	Remove an index	`tableName`, `indexName`

Table Maintenance

Tool	Description	Parameters
`empty_table`	Delete all records (keeps structure)	`tableName`
`pack_table`	Compact table, reclaim deleted space	`tableName`
`reindex_table`	Rebuild an index	`tableName`, `indexName`
`recover_table`	Recover records from broken table	`tableName`
`change_password`	Change table password	`tableName`, `oldPassword`, `newPassword`
`get_autoinc_value`	Get next auto-increment value	`tableName`

Transactions

Tool	Description	Parameters
`batch_execute`	Execute multiple SQL in one transaction	`statements` (JSON array), `snapshot?`

Utility

Tool	Description	Parameters
`count_records`	Fast record count via metadata	`tableName`
`list_indexes`	List all indexes on a table	`tableName`
`explain_query`	Show query execution plan	`sql`

Available Resources

URI	Description
`nexusdb://server`	Connection status and server info
`nexusdb://tables`	List of all tables
`nexusdb://schema`	Schema overview with record counts

Column Types

For create_table and add_column:

AutoInc - Auto-incrementing integer
ShortString - ANSI string (specify size)
WideString - Unicode string (specify size)
Integer - 32-bit integer
Int64 - 64-bit integer
Word - 16-bit unsigned
Byte - 8-bit unsigned
Boolean - True/False
Float - Double precision
Currency - Currency type
DateTime - Date and time
Date - Date only
Time - Time only
Blob - Binary data
Memo - Large text

Default Value Types

For add_column:

CurrentDateTime - Auto-populate with current timestamp
CurrentUser - Auto-populate with current user

Statement Switches

Prefix SQL statements with switches to control execution:

Switch	Syntax	Purpose
`#T`	`#T 5000`	Timeout in milliseconds
`#I`	`#I-`	Disable index optimization
`#S`	`#S-`	Disable query simplification
`#L`	`#L+`	Enable query logging (used by `explain\_query`)
`#B`	`#B+`	Force BLOB copying

Example: #T 10000 SELECT * FROM LargeTable WHERE Status = 'Active'

Example Usage

Create a table

{
  "name": "create_table",
  "arguments": {
    "tableName": "Customers",
    "columns": "[{"name":"ID","type":"AutoInc"},{"name":"Name","type":"ShortString","size":100},{"name":"Email","type":"ShortString","size":255}]"
  }
}

Insert a record

{
  "name": "insert_record",
  "arguments": {
    "tableName": "Customers",
    "data": "{"Name":"John Doe","Email":"john@example.com"}"
  }
}

Query data

{
  "name": "execute_query",
  "arguments": {
    "sql": "SELECT * FROM Customers WHERE Name LIKE 'J%'"
  }
}

Integration with Claude Code

Simply run

 claude mcp add --transport http nxmcp http://localhost:3000/mcp

Integration with Claude Desktop

Claude Desktop (currently?) does not support localhost URLs. You can try a proxy like node mcp-remote.

License

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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