Feat: pass UI data with tools

[tevanburen]

Documentation

Description

This update adds MCP UI decorator functionality and metadata handling to the MCP framework.

Changes Made

MakePythonMCP

• Added MCP UI decorator that takes in a map and puts it in the smss_mcp_ui key in metadata
• Validates displayLocation against valid types

MakePixelMCP and MakeEngineMCP

• Now accept mcpMetadata parameter with values for:
  • loadingMessage
  • resourceURI
  • displayLocation
• Validates location parameter
• Allows any values for URI and loading message
• Breaking Change: All MCPs will now have the SMSS_MCP_UI key in metadata (can be an empty map)

How to Test

Python Implementation

1. Add the import to your Python file:

from smssutil import mcp_metadata

Add the decorator above your MCP method:

@mcp_metadata({
    "resourceURI": None,
    "displayLocation": "inline"
})

Verify metadata by calling MakePythonMCP. The MCP JSON should contain:

"_meta": {
    "generated_on": "2026-01-23",
    "SMSS_MCP_EXECUTION": "ask",
    "SMSS_MCP_UI": {
        "resourceURI": null,
        "displayLocation": "inline"
    }
}

Pixel Implementation
Call MakePixelMCP or MakeEngineMCP with:

Your desired reactors to convert into MCPs
mcpMetadata parameter containing a list of maps (one per reactor)
Example:

MakePixelMCP(
    reactor=["ToPdf"], 
    mcpMetadata=[{
        "SMSS_MCP_EXECUTION": "fake execution type", 
        "SMSS_MCP_UI": {
            "loadingMessage": "Loading tool", 
            "displayLocation": "inline"
        }
    }]
)

Validate the metadata:

"_meta": {
   "SMSS_MCP_UI": {
        "loadingMessage": "Loading tool",
        "displayLocation": "inline"
    },
    "SMSS_MCP_EXECUTION": "ask"
},

[themaherkhalil]

Note: switched from the proposed @mcp_ui to @mcp_metadata. @mcp_metadata will take in "execution" value and @mcp_execution is now deprecated.

[github-actions]

@CodiumAI-Agent /update_changelog