Oh My Posh Validator

title: MCP Validator Function description: 'Azure Function implementing the Model Context Protocol server for validating oh-my-posh configurations'

Overview

This directory contains the Azure Function that implements the Model Context Protocol (MCP) server for validating oh-my-posh configurations.

Endpoints

• POST /api/mcp - MCP server endpoint that handles validation requests
• GET /api/mcp - Returns server information and available tools

Supported Tools

validate_config

Validate an oh-my-posh configuration.

• Supports JSON, YAML, and TOML formats
• Returns detailed validation errors with JSON paths

validate_segment

Validate a segment snippet (individual prompt segment).

• Validates against the segment schema definition
• Useful for testing individual segments before adding them to a full configuration
• Supports JSON, YAML, and TOML formats

Usage

As an MCP Server

Configure your MCP client to connect to this server:

{  "mcpServers": {    "oh-my-posh-validator": {      "type": "http",      "url": "https://ohmyposh.dev/api/mcp"    }  }}

Direct HTTP Requests

Get Server Info

curl https://ohmyposh.dev/api/mcp

List Available Tools

curl -X POST https://ohmyposh.dev/api/mcp \  -H "Content-Type: application/json" \  -d '{    "jsonrpc": "2.0",    "method": "tools/list",    "id": 1  }'

Validate a Configuration

curl -X POST https://ohmyposh.dev/api/mcp \  -H "Content-Type: application/json" \  -d '{    "jsonrpc": "2.0",    "method": "tools/call",    "params": {      "name": "validate_config",      "arguments": {        "content": "{\"$schema\":\"https://raw.githubusercontent.com/JanDeDobbeleer/oh-my-posh/main/themes/schema.json\",\"blocks\":[]}",        "format": "json"      }    },    "id": 1  }'

Validate a Segment Snippet

curl -X POST https://ohmyposh.dev/api/mcp \  -H "Content-Type: application/json" \  -d '{    "jsonrpc": "2.0",    "method": "tools/call",    "params": {      "name": "validate_segment",      "arguments": {        "content": "{\"type\":\"path\",\"style\":\"powerline\",\"foreground\":\"#ffffff\",\"background\":\"#61AFEF\",\"template\":\" {{ .Path }} \"}",        "format": "json"      }    },    "id": 2  }'

Response Format

The validation result includes:

• valid: Boolean indicating if the configuration is valid
• errors: Array of validation errors (if any)
• warnings: Array of warnings (best practices, deprecations)
• detectedFormat: The detected or specified format
• parsedConfig: The parsed configuration object (for debugging)

Example response:

{  "jsonrpc": "2.0",  "result": {    "content": [      {        "type": "text",        "text": "{          \"valid\": true,          \"errors\": [],          \"warnings\": [            {              \"path\": \"$schema\",              \"message\": \"Consider adding \\\"$schema\\\" property for better editor support.\",              \"type\": \"recommendation\"            }          ],          \"detectedFormat\": \"json\",          \"parsedConfig\": {...}        }"      }    ]  },  "id": 1}

Development

To test locally:

cd website/apinpm installnpm start

Then send requests to http://localhost:7071/api/mcp

Publishing to MCP Registry

This server is published to the MCP Registry using GitHub Actions.

Publishing

Publishing is triggered automatically when you push a version tag (same as oh-my-posh releases):

git tag v9.0.0git push origin v9.0.0

The workflow will:

1. Extract version from the tag (e.g., v9.0.0 → 9.0.0)
2. Update server.json version to match
3. Validate the server.json file
4. Authenticate with the MCP Registry using GitHub OIDC
5. Publish the server to the registry

Note: The MCP server version will stay in sync with oh-my-posh versions automatically.

Files

• server.json - MCP Registry server configuration
• server.schema.json - JSON schema for validation
• validate-server.js - Validation script
• .github/workflows/publish-mcp.yml - GitHub Actions workflow

Validating server.json Locally

cd website/apinpm installcd mcpnode validate-server.js