Ember MCP Server

Instructions

Implementation Reference

• index.js:307-404 (handler)

  The primary handler function that processes the tool call, fetches NPM package data using NpmService, formats it into a comprehensive Markdown response including description, versions, dependencies, metadata, and more.
  async handleGetNpmPackageInfo(args) { const { packageName } = args; try { const packageInfo = await this.npmService.getPackageInfo(packageName); const formatted = this.npmService.formatPackageInfo(packageInfo); let text = `# ${formatted.name}\n\n`; text += `**Description:** ${formatted.description}\n\n`; text += `**Latest Version:** ${formatted.latestVersion}\n\n`; // Dist tags if (Object.keys(formatted.distTags).length > 0) { text += `**Distribution Tags:**\n`; for (const [tag, version] of Object.entries(formatted.distTags)) { text += ` - ${tag}: ${version}\n`; } text += `\n`; } // Metadata if (formatted.license) { text += `**License:** ${formatted.license}\n`; } if (formatted.author) { text += `**Author:** ${formatted.author}\n`; } if (formatted.homepage) { text += `**Homepage:** ${formatted.homepage}\n`; } if (formatted.repository) { text += `**Repository:** ${formatted.repository}\n`; } // Keywords if (formatted.keywords.length > 0) { text += `\n**Keywords:** ${formatted.keywords.join(', ')}\n`; } // Dependencies const depCount = Object.keys(formatted.dependencies).length; const devDepCount = Object.keys(formatted.devDependencies).length; const peerDepCount = Object.keys(formatted.peerDependencies).length; if (depCount > 0 || devDepCount > 0 || peerDepCount > 0) { text += `\n**Dependencies:**\n`; if (depCount > 0) { text += ` - ${depCount} runtime dependencies\n`; } if (peerDepCount > 0) { text += ` - ${peerDepCount} peer dependencies\n`; } if (devDepCount > 0) { text += ` - ${devDepCount} dev dependencies\n`; } } // Engines if (Object.keys(formatted.engines).length > 0) { text += `\n**Engine Requirements:**\n`; for (const [engine, version] of Object.entries(formatted.engines)) { text += ` - ${engine}: ${version}\n`; } } // Dates if (formatted.created) { text += `\n**Created:** ${new Date(formatted.created).toLocaleDateString()}\n`; } if (formatted.lastPublished) { text += `**Last Published:** ${new Date(formatted.lastPublished).toLocaleDateString()}\n`; } // Maintainers if (formatted.maintainers.length > 0) { text += `\n**Maintainers:** ${formatted.maintainers.length} maintainer(s)\n`; } return { content: [ { type: "text", text: text, }, ], }; } catch (error) { return { content: [ { type: "text", text: `Error fetching package information: ${error.message}`, }, ], isError: true, }; } }
• index.js:135-145 (schema)

  Input schema defining the expected parameters for the get_npm_package_info tool: a required 'packageName' string.
  inputSchema: { type: "object", properties: { packageName: { type: "string", description: "Name of the npm package (e.g., 'ember-source', '@glimmer/component', 'ember-cli')", }, }, required: ["packageName"], },
• index.js:131-146 (registration)

  Registration of the 'get_npm_package_info' tool in the ListTools response, including name, description, and input schema.
  { name: "get_npm_package_info", description: "Get comprehensive information about an npm package including latest version, description, dependencies, maintainers, and more. Essential for understanding package details before upgrading dependencies.", inputSchema: { type: "object", properties: { packageName: { type: "string", description: "Name of the npm package (e.g., 'ember-source', '@glimmer/component', 'ember-cli')", }, }, required: ["packageName"], }, },
• lib/npm-service.js:16-32 (helper)

  Helper method in NpmService that fetches raw package information from the NPM registry API using node-fetch.
  async getPackageInfo(packageName) { try { const response = await fetch(`${this.registryUrl}/${packageName}`); if (!response.ok) { if (response.status === 404) { throw new Error(`Package "${packageName}" not found on npm registry`); } throw new Error(`Failed to fetch package info: ${response.statusText}`); } const data = await response.json(); return data; } catch (error) { throw new Error(`Error fetching npm package info: ${error.message}`); } }
• lib/npm-service.js:59-82 (helper)

  Helper method in NpmService that processes raw NPM package data into a formatted object with extracted fields like versions, metadata, dependencies, etc., used by the main handler.
  formatPackageInfo(packageInfo) { const latestVersion = packageInfo['dist-tags']?.latest; const latestVersionData = latestVersion ? packageInfo.versions[latestVersion] : null; return { name: packageInfo.name, description: packageInfo.description || 'No description available', latestVersion: latestVersion || 'Unknown', distTags: packageInfo['dist-tags'] || {}, homepage: packageInfo.homepage || latestVersionData?.homepage || null, repository: packageInfo.repository?.url || latestVersionData?.repository?.url || null, license: latestVersionData?.license || 'Unknown', author: this.formatAuthor(packageInfo.author || latestVersionData?.author), maintainers: packageInfo.maintainers || [], keywords: latestVersionData?.keywords || [], dependencies: latestVersionData?.dependencies || {}, devDependencies: latestVersionData?.devDependencies || {}, peerDependencies: latestVersionData?.peerDependencies || {}, engines: latestVersionData?.engines || {}, lastPublished: packageInfo.time?.[latestVersion] || null, created: packageInfo.time?.created || null, modified: packageInfo.time?.modified || null, }; }