MCP for Runtime Developer Reference

Technical reference for building MCP tools that access FrameworX runtime data.

Reference → MCP for Runtime Developer Reference

Overview

This document provides technical details for developers building MCP tools that interact with FrameworX runtime. It covers data access APIs, path syntax, available namespaces, and tool design guidelines.

For the object model structure, see Object Model Quick Reference.

Core APIs

GetCurrentValue

Primary API for reading any value from the runtime.

csharp

bool success = TMCPServer.DataAccess.GetCurrentValue(
    string path,           // Full path to object
    out object value,      // Returned value
    out int quality,       // 0=Bad, 192=Good
    out DateTime timestamp // Last update time
);

This API accepts any namespace path:

GetChildrenElements

Returns children of any path as a DataTable.

csharp

DataTable children = TK.GetChildrenElements(string path);

Behavior depends on path type:

GetTagHistorian

Query time-series data from the Historian.

csharp

DataTable history = TK.GetTagHistorian(
    string tagName,
    DateTimeOffset startTime,
    TimeSpan duration
);

Returns columns: Timestamp, Value, Quality

Path Syntax

Separators

Path Structure

Tag.Plant1/Line2/Temperature1.Value
?   ?      ?     ?            ??? Property (member access with .)
?   ?      ?     ??? Tag name
?   ?      ??? Subfolder (hierarchy with /)
?   ??? Root folder (hierarchy with /)
??? Namespace

Path Examples

Tag Properties

Properties accessible via Tag.{name}.{property}:

Server Namespace Properties

Server.SystemMonitor.*

Server.*

Server.Redundancy.*

Alarm Namespace Properties

Alarm.*

Alarm.Group.{name}.*

Alarm History Database

Historical alarm records are stored in Dataset.DB.AlarmHistorian.

Common columns: TagName, Message, ActiveTime, AckTime, NormTime, UserName, Priority, Area, GroupName

Quality Codes

Standard OPC quality values:

MCP Tool Design Guidelines

Tool Naming Conventions

Description Best Practices

Effective tool descriptions help AI assistants choose the right tool:

1. First sentence: State the purpose clearly
2. Returns: Describe what data is returned
3. Use for: List appropriate use cases
4. Do NOT use: Clarify when other tools are better (prevents misuse)
5. Examples: Provide sample input values

Template:

"[What it does in one sentence]. " +
"Returns [what is returned]. " +
"Use for: [use case 1], [use case 2], [use case 3]. " +
"[When NOT to use, if applicable]. " +
"Examples: [example1], [example2], [example3]."

Parameter Description Best Practices

1. State the expected format (e.g., "ISO 8601 format")
2. Provide concrete examples
3. Explain path syntax when relevant

Example:

csharp

[Description("Tag name (e.g., 'Tag.Temperature1', 'Tag.Plant1/Line2/Pressure')")]
string name

Built-in MCP Tools Reference

GetValue

Reads current value from any namespace path.

GetTagHistory

Queries time-series data from Historian.

GetActiveAlarms

Returns currently active alarms.

GetChildren

Browses namespace structure.

GetTagMetadata

Returns tag metadata without current value.

See Also

• Object Model Quick Reference — Complete object reference
• Built-in Namespaces Reference — All namespace properties
• MCP for Runtime Connector — Configuration and setup
• MCP for Runtime Tutorial — Step-by-step guide