accounted/extensions/general/mcp-server/__tests__/lazy-auth.test.ts

import { beforeEach, describe, expect, it, vi } from 'vitest'
import { eventBus } from '@/lib/events/bus'

// Lazy authentication (issue #1814 PR 2): a client with no token may connect,
// list the catalog and call the public documentation tools; anything that
// touches a company answers 401 + WWW-Authenticate at the transport level,
// which is what Claude / Claude Code / Codex turn into their Connect prompt.

const mocks = vi.hoisted(() => ({
  validateApiKey: vi.fn(),
  checkRateLimit: vi.fn(),
}))

vi.mock('@/lib/auth/api-keys', async (importOriginal) => {
  const actual = await importOriginal<typeof import('@/lib/auth/api-keys')>()
  return {
    ...actual,
    validateApiKey: (...args: unknown[]) => mocks.validateApiKey(...args),
    createServiceClientNoCookies: vi.fn(() => ({
      from: vi.fn(() => {
        throw new Error('anonymous requests must not touch tenant tables')
      }),
    })),
  }
})

vi.mock('@/lib/auth/rate-limit-http', () => ({
  checkRateLimit: (...args: unknown[]) => mocks.checkRateLimit(...args),
}))

// Skills come from the filesystem/registry; keep the list deterministic and
// free of Supabase so the public tools can run under the throwing client.
vi.mock('../skills', async (importOriginal) => {
  const actual = await importOriginal<typeof import('../skills')>()
  return {
    ...actual,
    loadAllSkills: vi.fn().mockResolvedValue([
      {
        slug: 'month-end-close',
        name: 'Month-end close',
        summary: 'Close a month.',
        tags: ['close'],
        tier: 'workflow',
        body: 'Steps…',
        applicability: null,
      },
    ]),
  }
})

import { handleMcpRequest } from '../server'

const ENDPOINT = 'http://localhost:3000/api/extensions/ext/mcp-server/mcp'

function rpc(
  method: string,
  params?: Record<string, unknown>,
  opts: { token?: string; ip?: string } = {}
): Request {
  const headers: Record<string, string> = { 'Content-Type': 'application/json' }
  if (opts.token) headers.Authorization = `Bearer ${opts.token}`
  if (opts.ip) headers['x-forwarded-for'] = opts.ip
  return new Request(ENDPOINT, {
    method: 'POST',
    headers,
    body: JSON.stringify({ jsonrpc: '2.0', id: 7, method, ...(params ? { params } : {}) }),
  })
}

describe('MCP lazy authentication', () => {
  beforeEach(() => {
    vi.clearAllMocks()
    eventBus.clear()
    mocks.checkRateLimit.mockResolvedValue({ ok: true })
    mocks.validateApiKey.mockResolvedValue({
      userId: 'user-1',
      companyId: '11111111-1111-4111-8111-111111111111',
      scopes: ['companies:read'],
      apiKeyId: 'key-1',
      apiKeyName: 'Test key',
      mode: 'live',
    })
  })

  it('answers initialize without a token and says the client is not connected', async () => {
    const response = await handleMcpRequest(rpc('initialize', { protocolVersion: '2025-06-18' }))
    expect(response.status).toBe(200)
    const body = await response.json()
    expect(body.result.instructions).toContain('NOT CONNECTED YET')
    expect(body.result.instructions).toContain('gnubok_search_tools')
    expect(mocks.validateApiKey).not.toHaveBeenCalled()
  })

  it('lists the full default catalog without a token so protected tools can be called', async () => {
    const response = await handleMcpRequest(rpc('tools/list'))
    expect(response.status).toBe(200)
    const body = await response.json()
    const names = (body.result.tools as Array<{ name: string }>).map((t) => t.name)
    expect(names).toContain('gnubok_search_tools')
    // A company-scoped tool is listed too: calling it is the connect trigger.
    expect(names).toContain('gnubok_list_companies')
    expect(names.length).toBeGreaterThan(20)
  })

  it('runs a public documentation tool without a token', async () => {
    const response = await handleMcpRequest(
      rpc('tools/call', { name: 'gnubok_list_skills', arguments: {} })
    )
    expect(response.status).toBe(200)
    const body = await response.json()
    expect(body.result.isError).not.toBe(true)
    const payload = JSON.parse(body.result.content[0].text)
    expect(payload.count).toBe(1)
    expect(payload.skills[0].slug).toBe('month-end-close')
    expect(mocks.validateApiKey).not.toHaveBeenCalled()
  })

  it('ignores a company_id on a public tool when anonymous instead of touching tenant tables', async () => {
    const response = await handleMcpRequest(
      rpc('tools/call', {
        name: 'gnubok_list_skills',
        arguments: { company_id: '11111111-1111-4111-8111-111111111111' },
      })
    )
    expect(response.status).toBe(200)
    const body = await response.json()
    expect(body.result.isError).not.toBe(true)
  })

  it('challenges a protected tool call with a transport-level 401 + WWW-Authenticate', async () => {
    const response = await handleMcpRequest(
      rpc('tools/call', { name: 'gnubok_list_companies', arguments: {} })
    )
    expect(response.status).toBe(401)
    expect(response.headers.get('WWW-Authenticate')).toMatch(
      /^Bearer resource_metadata="http:\/\/localhost:3000\/\.well-known\/oauth-protected-resource"$/
    )
  })

  it('challenges tenant-scoped methods (resources/read, tasks/get) without a token', async () => {
    for (const [method, params] of [
      ['resources/read', { uri: 'Accounted://company/current' }],
      ['tasks/get', { taskId: 'x' }],
    ] as const) {
      const response = await handleMcpRequest(rpc(method, params as Record<string, unknown>))
      expect(response.status, method).toBe(401)
      expect(response.headers.get('WWW-Authenticate'), method).toContain('resource_metadata')
    }
  })

  it('keeps a tokenless unparseable body on the pre-lazy-auth answer (401, no detail)', async () => {
    const response = await handleMcpRequest(
      new Request(ENDPOINT, { method: 'POST', body: 'not json' })
    )
    expect(response.status).toBe(401)
  })

  it('rate-limits anonymous calls per truncated IP', async () => {
    mocks.checkRateLimit.mockResolvedValueOnce({
      ok: false,
      response: new Response('slow down', { status: 429 }),
    })
    const response = await handleMcpRequest(
      rpc('tools/list', undefined, { ip: '203.0.113.42, 10.0.0.1' })
    )
    expect(response.status).toBe(429)
    expect(mocks.checkRateLimit).toHaveBeenCalledWith(
      expect.objectContaining({ prefix: 'mcp:anonymous', identifier: '203.0.113.0/24' })
    )
  })

  it('never rate-limits or bypasses validation for a token bearer', async () => {
    const response = await handleMcpRequest(
      rpc('tools/call', { name: 'gnubok_list_skills', arguments: {} }, { token: 'gnubok_sk_x' })
    )
    expect(response.status).toBe(200)
    expect(mocks.validateApiKey).toHaveBeenCalledWith('gnubok_sk_x')
    expect(mocks.checkRateLimit).not.toHaveBeenCalled()
  })

  it('still rejects an invalid token with 401 even on an anonymous-capable method', async () => {
    mocks.validateApiKey.mockResolvedValueOnce({ error: 'Invalid API key', status: 401 })
    const response = await handleMcpRequest(rpc('tools/list', undefined, { token: 'gnubok_sk_bad' }))
    expect(response.status).toBe(401)
  })
})