Infracost MCP Server

Instructions

Implementation Reference

• src/cli.ts:112-155 (handler)

  Core handler function that executes the 'infracost output' CLI command with resolved paths and options, captures stdout/stderr/JSON, handles errors.
  export async function executeOutput(options: OutputOptions): Promise<CommandResult> { try { const args = ['output', '--path', resolve(options.path)]; if (options.format) { args.push('--format', options.format); } if (options.outFile) { args.push('--out-file', resolve(options.outFile)); } if (options.fields && options.fields.length > 0) { args.push('--fields', options.fields.join(',')); } if (options.showSkipped) { args.push('--show-skipped'); } const { stdout, stderr } = await execFileAsync('infracost', args, { maxBuffer: 10 * 1024 * 1024, }); let parsedData; if (options.format === 'json' && !options.outFile && stdout.trim()) { try { parsedData = JSON.parse(stdout); } catch (e) {} } return { success: true, output: options.outFile ? `Output saved to ${options.outFile}` : stdout, error: stderr || undefined, data: parsedData, }; } catch (error) { return { success: false, error: error instanceof Error ? error.message : 'Unknown error occurred', }; } }
• src/tools.ts:334-356 (handler)

  MCP tool handler in InfracostTools class: validates input, checks CLI installation, delegates to executeOutput, formats MCP response.
  async handleOutput(args: z.infer<typeof OutputSchema>) { const isInstalled = await checkInfracostInstalled(); if (!isInstalled) { throw new Error( 'Infracost CLI is not installed. Please install it from https://www.infracost.io/docs/' ); } const result = await executeOutput(args); if (!result.success) { throw new Error(result.error || 'Output command failed'); } return { content: [ { type: 'text', text: result.output || 'Output generated successfully', }, ], }; }
• src/index.ts:714-717 (handler)

  Server request handler dispatch for CallToolRequest: parses arguments with OutputSchema and calls tools.handleOutput.
  case 'infracost_output': { const validatedArgs = OutputSchema.parse(args); return await tools.handleOutput(validatedArgs); }
• src/tools.ts:28-46 (schema)

  Zod schema defining input parameters and validation for the infracost_output tool.
  export const OutputSchema = z.object({ path: z.string().describe('Path to Infracost JSON file(s)'), format: z .enum([ 'json', 'table', 'html', 'diff', 'github-comment', 'gitlab-comment', 'azure-repos-comment', 'bitbucket-comment', ]) .optional() .describe('Output format'), outFile: z.string().optional().describe('Save output to file'), fields: z.array(z.string()).optional().describe('Fields to include in output'), showSkipped: z.boolean().optional().describe('Show skipped resources'), });
• src/index.ts:134-175 (registration)

  Tool registration in ListToolsResponse: defines name, description, and input schema for discovery by MCP clients.
  { name: 'infracost_output', description: 'Combine and format Infracost JSON files. Useful for merging multiple cost estimates or converting formats. Requires infracost CLI to be installed.', inputSchema: { type: 'object', properties: { path: { type: 'string', description: 'Path to Infracost JSON file(s) - supports glob patterns', }, format: { type: 'string', enum: [ 'json', 'table', 'html', 'diff', 'github-comment', 'gitlab-comment', 'azure-repos-comment', 'bitbucket-comment', ], description: 'Output format', }, outFile: { type: 'string', description: 'Save output to a file', }, fields: { type: 'array', items: { type: 'string' }, description: 'Fields to include in output (e.g., ["price", "monthlyQuantity"])', }, showSkipped: { type: 'boolean', description: 'Show skipped resources in output', }, }, required: ['path'], }, },