Fountain Pen Ink MCP Server

Instructions

Implementation Reference

• src/index.ts:481-510 (handler)

  The main handler function that implements the analyze_color tool logic: parses hex color to RGB, finds closest matching inks, determines color family and description using utilities, and returns a structured JSON analysis response.

  private analyzeColor(colorHex: string, maxResults: number = 5): MCPTextResponse {
    try {
      const rgb = hexToRgb(colorHex);
      const closestInks = findClosestInks(rgb, this.inkColors, maxResults);
  
      const results: SearchResult[] = closestInks.map((ink) => {
        const metadata = this.getInkMetadata(ink.ink_id);
        return createSearchResult(ink, metadata, ink.distance);
      });
  
      const analysis: ColorAnalysis = {
        hex: colorHex,
        rgb,
        closest_inks: results,
        color_family: getColorFamily(rgb), // No conversion needed
        description: getColorDescription(rgb), // No conversion needed
      };
  
      return {
        content: [
          {
            type: 'text',
            text: JSON.stringify(analysis, null, 2),
          },
        ],
      } satisfies MCPTextResponse;
    } catch {
      throw new Error(`Invalid color format: ${colorHex}. Please use hex format like #FF5733`);
    }
  }

• src/index.ts:211-229 (registration)

  Registration of the analyze_color tool in the ListTools handler, including name, description, and input schema definition.

  {
    name: 'analyze_color',
    description: 'Analyze a color and provide ink knowledge context',
    inputSchema: {
      type: 'object',
      properties: {
        color: {
          type: 'string',
          description: 'Hex color code (e.g., "#FF5733")',
        },
        max_results: {
          type: 'number',
          description: 'Maximum number of closest inks to return (default: 5)',
          default: 5,
        },
      },
      required: ['color'],
    },
  },

• src/index.ts:292-293 (registration)

  Dispatch/registration of the analyze_color tool in the CallToolRequest switch statement, mapping arguments to the handler method.

  case 'analyze_color':
    return this.analyzeColor(args.color as string, (args.max_results as number) || 5);

• src/index.ts:214-228 (schema)

  Input schema definition for the analyze_color tool, specifying parameters for color (required hex string) and optional max_results.

  inputSchema: {
    type: 'object',
    properties: {
      color: {
        type: 'string',
        description: 'Hex color code (e.g., "#FF5733")',
      },
      max_results: {
        type: 'number',
        description: 'Maximum number of closest inks to return (default: 5)',
        default: 5,
      },
    },
    required: ['color'],
  },