@pulumi/mcp-server

Instructions

Implementation Reference

• src/pulumi/cli.ts:21-57 (handler)

  Executes Pulumi preview using the automation API, formats and returns the change summary and stdout.

      handler: async (args: PreviewArgs) => {
        const stackArgs: automation.LocalProgramArgs = {
          stackName: args.stackName ?? 'dev',
          workDir: args.workDir
        };
  
        const stack = await automation.LocalWorkspace.createOrSelectStack(stackArgs);
  
        // Run preview
        const previewResult = await stack.preview({ diff: true });
  
        // Format the changes
        const changes = previewResult.changeSummary;
        const changesSummary = [
          `Create: ${changes.create}`,
          `Update: ${changes.update}`,
          `Delete: ${changes.delete}`,
          `Same: ${changes.same}`
        ].join('\n');
  
        return {
          description: 'Pulumi Preview Results',
          content: [
            {
              type: 'text' as const,
              text: `
  Preview Results for stack: ${stack.name}
  
  Changes:
  ${changesSummary}
  
  ${previewResult.stdout || 'No additional output'}
  `
            }
          ]
        };
      }

• src/pulumi/cli.ts:17-20 (schema)

  Input schema using Zod for workDir (required) and stackName (optional, defaults to 'dev').

  schema: {
    workDir: z.string().describe('The working directory of the program.'),
    stackName: z.string().optional().describe("The associated stack name. Defaults to 'dev'.")
  },

• src/server/server.ts:69-79 (registration)

  Registers all Pulumi CLI commands, including 'preview' as 'pulumi-cli-preview', in the MCP server with error handling.

  Object.entries(cliCommands).forEach(([commandName, command]) => {
    const toolName = `pulumi-cli-${commandName}`;
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    this.tool(toolName, command.description, command.schema, async (args: any) => {
      try {
        return await command.handler(args);
      } catch (error) {
        return handleError(error, toolName);
      }
    });
  });