Broken Link Checker MCP Server

Instructions

Implementation Reference

• index.js:26-56 (handler)

  The core handler function that performs the link checking on a single page using HtmlUrlChecker from the broken-link-checker library. It enqueues the URL, processes link results, and resolves with results and any errors.

  function checkPageLinks(url, options = {}) {
    return new Promise((resolve, reject) => {
      const results = [];
      const errors = [];
  
      const htmlChecker = new HtmlUrlChecker(options, {
        link: (result) => {
          results.push({
            url: result.url.resolved,
            base: result.base.resolved,
            html: {
              tagName: result.html.tagName,
              text: result.html.text,
            },
            broken: result.broken,
            brokenReason: result.brokenReason,
            excluded: result.excluded,
            excludedReason: result.excludedReason,
            http: {
              statusCode: result.http?.response?.statusCode,
            },
          });
        },
        complete: () => {
          resolve({ results, errors });
        },
      });
  
      htmlChecker.enqueue(url);
    });
  }

• index.js:107-128 (schema)

  Input schema definition for the check_page_links tool, specifying the required 'url' parameter and optional boolean flags for link filtering and robot exclusion respect.

  inputSchema: {
    type: "object",
    properties: {
      url: {
        type: "string",
        description: "The URL of the page to check for broken links",
      },
      excludeExternalLinks: {
        type: "boolean",
        description:
          "If true, only check internal links (default: false)",
        default: false,
      },
      honorRobotExclusions: {
        type: "boolean",
        description:
          "If true, respect robots.txt and meta robots tags (default: true)",
        default: true,
      },
    },
    required: ["url"],
  },

• index.js:103-129 (registration)

  Tool registration in the ListToolsRequestSchema handler, defining the tool's name, description, and input schema.

  {
    name: "check_page_links",
    description:
      "Check all links on a single HTML page for broken links. Returns detailed information about each link found including broken status, HTTP status codes, and reasons for failure.",
    inputSchema: {
      type: "object",
      properties: {
        url: {
          type: "string",
          description: "The URL of the page to check for broken links",
        },
        excludeExternalLinks: {
          type: "boolean",
          description:
            "If true, only check internal links (default: false)",
          default: false,
        },
        honorRobotExclusions: {
          type: "boolean",
          description:
            "If true, respect robots.txt and meta robots tags (default: true)",
          default: true,
        },
      },
      required: ["url"],
    },
  },

• server.js:38-68 (handler)

  Identical core handler function for the HTTP/SSE server version, performing link checking using HtmlUrlChecker.

  function checkPageLinks(url, options = {}) {
    return new Promise((resolve, reject) => {
      const results = [];
      const errors = [];
  
      const htmlChecker = new HtmlUrlChecker(options, {
        link: (result) => {
          results.push({
            url: result.url.resolved,
            base: result.base.resolved,
            html: {
              tagName: result.html.tagName,
              text: result.html.text,
            },
            broken: result.broken,
            brokenReason: result.brokenReason,
            excluded: result.excluded,
            excludedReason: result.excludedReason,
            http: {
              statusCode: result.http?.response?.statusCode,
            },
          });
        },
        complete: () => {
          resolve({ results, errors });
        },
      });
  
      htmlChecker.enqueue(url);
    });
  }

• server.js:119-140 (schema)

  Input schema for check_page_links tool in the server.js version, matching the stdio version.

  inputSchema: {
    type: "object",
    properties: {
      url: {
        type: "string",
        description: "The URL of the page to check for broken links",
      },
      excludeExternalLinks: {
        type: "boolean",
        description:
          "If true, only check internal links (default: false)",
        default: false,
      },
      honorRobotExclusions: {
        type: "boolean",
        description:
          "If true, respect robots.txt and meta robots tags (default: true)",
        default: true,
      },
    },
    required: ["url"],
  },