@McpExpose

The @McpExpose decorator and createMcpService(app, ConfigClass) ("@agboss/core/mcp") turn an AGBoss @Application into a standards-compliant Model Context Protocol (MCP) server. External MCP clients (Codex, Cursor, Windsurf, Claude Code, or another AGBoss application) can discover and call your exposed @WorkflowStart entry points and @Tool classes with full @Budget, @PiiPolicy, and @InputGuardrail / @OutputGuardrail enforcement.

Complete @McpExpose and createMcpService example

src/mcp/job-scout.expose.ts

import { Tool, WorkflowStart, createApp, type ToolHandler } from "@agboss/core";
import { Text, WorkflowStartTextDto } from "@agboss/core/dto";
import { McpExpose, createMcpService } from "@agboss/core/mcp";
import { JobScoutApplication } from "../job-scout.application.js";

export class JobQueryDto {
  @Text({ prompt: "Role keywords" })
  query!: string;
}

export class JobResultsDto {
  @Text({ prompt: "Formatted job matches" })
  text!: string;
}

@Tool({
  name: "search_jobs",
  description: "Searches open engineering roles",
  input: JobQueryDto,
  output: JobResultsDto,
})
export class SearchJobsTool implements ToolHandler<JobQueryDto, JobResultsDto> {
  run({ query }: JobQueryDto): Promise<JobResultsDto> {
    return Promise.resolve({ text: `Matches for ${query}` });
  }
}

@WorkflowStart({
  name: "chat-workflow-start",
  description: "Starts a Job Scout recruiting turn from an MCP client",
  input: WorkflowStartTextDto,
})
export class ChatWorkflowStart {}

@McpExpose({
  name: "job-scout-mcp",
  version: "1.0.0",
  exports: [SearchJobsTool, ChatWorkflowStart],
})
export class JobScoutMcpExpose {}

export async function serveMcpStdio() {
  const app = await createApp(JobScoutApplication);
  const service = createMcpService(app, JobScoutMcpExpose);
  await service.connectStdio();
}

test/job-scout.expose.test.ts

import { expect } from "vitest";
import { ExecutionStatus } from "@agboss/core";
import { replyWith, testTool, testWith } from "@agboss/core/testing";
import { JobScoutApplication, ScoutAgent } from "../src/job-scout.application.js";
import {
  ChatWorkflowStart,
  JobScoutMcpExpose,
  SearchJobsTool,
} from "../src/mcp/job-scout.expose.js";

const test = testWith(JobScoutApplication);

test("executes the MCP-exposed tool and workflow start entry point", async ({ app, mockLlm }) => {
  expect(JobScoutMcpExpose).toBeDefined();

  const runSearchTool = testTool(SearchJobsTool);
  const { output: toolOut } = await runSearchTool({ query: "Staff TypeScript" });
  expect(toolOut.text).toContain("Staff TypeScript");

  mockLlm(ScoutAgent).thenReturn(replyWith("Found 3 Staff TypeScript roles."));
  const wfOut = await app.execute(ChatWorkflowStart, { text: "Find Staff TypeScript roles" });
  expect(wfOut.status).toBe(ExecutionStatus.Finished);
});

What options does @McpExpose accept?

Option	Type	Required	Description
name	string	Yes	MCP server identifier advertised during protocol initialization (e.g., "job-scout-mcp").
version	string	Yes	Semantic version of the exposed MCP surface (e.g., "1.0.0").
exports	readonly Class[]	Yes	Array of @Tool and @WorkflowStart classes exposed as callable MCP tools.