diff --git a/src/server/__tests__/skill-market.test.ts b/src/server/__tests__/skill-market.test.ts
index 131da521..8bdd92c1 100644
--- a/src/server/__tests__/skill-market.test.ts
+++ b/src/server/__tests__/skill-market.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'bun:test'
 import { normalizeClawHubList, normalizeClawHubScan } from '../services/skillMarket/clawhubAdapter.js'
+import { createSkillMarketService } from '../services/skillMarket/service.js'
 import { normalizeSkillHubDetail, normalizeSkillHubList } from '../services/skillMarket/skillhubAdapter.js'
 import {
   CLAWHUB_SCAN_RESPONSE,
@@ -386,3 +387,130 @@ describe('skill market source normalization', () => {
     })
   })
 })
+
+describe('skill market service source selection', () => {
+  it('uses ClawHub only in auto mode when ClawHub succeeds and marks installed skills', async () => {
+    const fetchCalls: string[] = []
+    const service = createSkillMarketService({
+      fetchImpl: async (url) => {
+        fetchCalls.push(String(url))
+        return Response.json(CLAWHUB_TOP_SKILLS_RESPONSE)
+      },
+      installedSkillNames: async () => new Set(['skill-vetter']),
+    })
+
+    const result = await service.listSkills({ source: 'auto', limit: 12, query: 'vetter', cursor: 'next-page' })
+
+    expect(fetchCalls).toHaveLength(1)
+    expect(fetchCalls[0]).toStartWith('https://clawhub.ai/api/v1/skills')
+    expect(fetchCalls[0]).toContain('sort=downloads')
+    expect(fetchCalls[0]).toContain('nonSuspiciousOnly=true')
+    expect(fetchCalls[0]).toContain('limit=12')
+    expect(fetchCalls[0]).toContain('query=vetter')
+    expect(fetchCalls[0]).toContain('cursor=next-page')
+    expect(result).toMatchObject({
+      source: 'clawhub',
+      sourceStatus: 'ok',
+      items: [
+        {
+          source: 'clawhub',
+          slug: 'skill-vetter',
+          installed: true,
+        },
+      ],
+    })
+  })
+
+  it('falls back to SkillHub in auto mode when ClawHub fails and marks installed skills', async () => {
+    const fetchCalls: string[] = []
+    const service = createSkillMarketService({
+      fetchImpl: async (url) => {
+        fetchCalls.push(String(url))
+        if (String(url).startsWith('https://clawhub.ai/')) {
+          return new Response('temporarily unavailable', { status: 503 })
+        }
+        return Response.json(SKILLHUB_TOP_SKILLS_RESPONSE)
+      },
+      installedSkillNames: new Set(['skill-vetter']),
+    })
+
+    const result = await service.listSkills({ source: 'auto', limit: 10, query: 'vetter', cursor: '3' })
+
+    expect(fetchCalls).toHaveLength(2)
+    expect(fetchCalls[0]).toStartWith('https://clawhub.ai/api/v1/skills')
+    expect(fetchCalls[1]).toStartWith('https://api.skillhub.cn/api/skills')
+    expect(fetchCalls[1]).toContain('sortBy=downloads')
+    expect(fetchCalls[1]).toContain('order=desc')
+    expect(fetchCalls[1]).toContain('limit=10')
+    expect(fetchCalls[1]).toContain('query=vetter')
+    expect(fetchCalls[1]).toContain('cursor=3')
+    expect(result.source).toBe('skillhub')
+    expect(result.sourceStatus).toBe('fallback')
+    expect(result.message).toContain('ClawHub unavailable')
+    expect(result.items[0]).toMatchObject({
+      source: 'skillhub',
+      slug: 'skill-vetter',
+      installed: true,
+    })
+  })
+
+  it("does not fallback to SkillHub when source is 'clawhub'", async () => {
+    const fetchCalls: string[] = []
+    const service = createSkillMarketService({
+      fetchImpl: async (url) => {
+        fetchCalls.push(String(url))
+        return new Response('temporarily unavailable', { status: 503 })
+      },
+      installedSkillNames: async () => new Set(),
+    })
+
+    await expect(service.listSkills({ source: 'clawhub' })).rejects.toThrow('ClawHub request failed')
+
+    expect(fetchCalls).toHaveLength(1)
+    expect(fetchCalls[0]).toStartWith('https://clawhub.ai/api/v1/skills')
+  })
+
+  it("uses SkillHub only when source is 'skillhub'", async () => {
+    const fetchCalls: string[] = []
+    const service = createSkillMarketService({
+      fetchImpl: async (url) => {
+        fetchCalls.push(String(url))
+        return Response.json(SKILLHUB_TOP_SKILLS_RESPONSE)
+      },
+      installedSkillNames: async () => new Set(),
+    })
+
+    const result = await service.listSkills({ source: 'skillhub', limit: 6, query: 'vetter', cursor: '2' })
+
+    expect(fetchCalls).toHaveLength(1)
+    expect(fetchCalls[0]).toStartWith('https://api.skillhub.cn/api/skills')
+    expect(fetchCalls[0]).toContain('sortBy=downloads')
+    expect(fetchCalls[0]).toContain('order=desc')
+    expect(fetchCalls[0]).toContain('limit=6')
+    expect(fetchCalls[0]).toContain('query=vetter')
+    expect(fetchCalls[0]).toContain('cursor=2')
+    expect(result.source).toBe('skillhub')
+    expect(result.items[0]).toMatchObject({
+      source: 'skillhub',
+      slug: 'skill-vetter',
+      installed: false,
+    })
+  })
+
+  it('rejects unsupported v1 sources instead of treating them as auto', async () => {
+    const fetchCalls: string[] = []
+    const service = createSkillMarketService({
+      fetchImpl: async (url) => {
+        fetchCalls.push(String(url))
+        return Response.json(CLAWHUB_TOP_SKILLS_RESPONSE)
+      },
+      installedSkillNames: async () => new Set(),
+    })
+
+    await expect(
+      service.listSkills({ source: 'anthropic-github' as 'auto' }),
+    ).rejects.toThrow('Unsupported skill market source')
+
+    expect(fetchCalls).toHaveLength(0)
+  })
+})
diff --git a/src/server/services/skillMarket/service.ts b/src/server/services/skillMarket/service.ts
new file mode 100644
index 00000000..bc7813d3
--- /dev/null
+++ b/src/server/services/skillMarket/service.ts
@@ -0,0 +1,172 @@
+import { normalizeClawHubList } from './clawhubAdapter.js'
+import { normalizeSkillHubList } from './skillhubAdapter.js'
+import type { SkillMarketItem, SkillMarketListResult } from './types.js'
+
+export type SkillMarketListSource = 'auto' | 'clawhub' | 'skillhub'
+
+export type SkillMarketListParams = {
+  source?: SkillMarketListSource
+  limit?: number
+  query?: string
+  cursor?: string
+  sort?: 'downloads' | 'installs' | 'stars' | 'updated' | 'trending'
+}
+
+type FetchImpl = typeof fetch
+type InstalledSkillNamesProvider = Set<string> | (() => Set<string> | Promise<Set<string>>)
+
+export type SkillMarketServiceOptions = {
+  fetchImpl?: FetchImpl
+  installedSkillNames?: InstalledSkillNamesProvider
+}
+
+export type SkillMarketService = {
+  listSkills: (params?: SkillMarketListParams) => Promise<SkillMarketListResult>
+  list: (params?: SkillMarketListParams) => Promise<SkillMarketListResult>
+}
+
+const CLAWHUB_SKILLS_URL = 'https://clawhub.ai/api/v1/skills'
+const SKILLHUB_SKILLS_URL = 'https://api.skillhub.cn/api/skills'
+const DEFAULT_LIMIT = 24
+const MAX_LIMIT = 100
+
+export function createSkillMarketService(options: SkillMarketServiceOptions = {}): SkillMarketService {
+  const fetchImpl = options.fetchImpl ?? fetch
+  const installedSkillNames = options.installedSkillNames
+
+  async function listSkills(params: SkillMarketListParams = {}): Promise<SkillMarketListResult> {
+    const source = params.source ?? 'auto'
+
+    if (source === 'clawhub') {
+      return withInstalled(await listClawHub(params))
+    }
+
+    if (source === 'skillhub') {
+      return withInstalled(await listSkillHub(params, 'ok'))
+    }
+
+    if (source !== 'auto') {
+      throw new Error(`Unsupported skill market source: ${source}`)
+    }
+
+    try {
+      return withInstalled(await listClawHub(params))
+    } catch (error) {
+      const fallback = await listSkillHub(params, 'fallback')
+      return withInstalled({
+        ...fallback,
+        sourceStatus: 'fallback',
+        message: `ClawHub unavailable: ${errorMessage(error)}`,
+      })
+    }
+  }
+
+  async function listClawHub(params: SkillMarketListParams): Promise<SkillMarketListResult> {
+    const url = new URL(CLAWHUB_SKILLS_URL)
+    url.searchParams.set('sort', clawHubSort(params.sort))
+    url.searchParams.set('nonSuspiciousOnly', 'true')
+    url.searchParams.set('limit', String(limitFor(params.limit)))
+    addOptionalParam(url, 'query', params.query)
+    addOptionalParam(url, 'cursor', params.cursor)
+
+    const payload = await requestJson(fetchImpl, url, 'ClawHub')
+    return normalizeClawHubList(payload)
+  }
+
+  async function listSkillHub(
+    params: SkillMarketListParams,
+    sourceStatus: SkillMarketListResult['sourceStatus'],
+  ): Promise<SkillMarketListResult> {
+    const url = new URL(SKILLHUB_SKILLS_URL)
+    url.searchParams.set('sortBy', skillHubSort(params.sort))
+    url.searchParams.set('order', 'desc')
+    url.searchParams.set('limit', String(limitFor(params.limit)))
+    addOptionalParam(url, 'query', params.query)
+    addOptionalParam(url, 'cursor', params.cursor)
+
+    const payload = await requestJson(fetchImpl, url, 'SkillHub')
+    return {
+      ...normalizeSkillHubList(payload),
+      sourceStatus,
+    }
+  }
+
+  async function withInstalled(result: SkillMarketListResult): Promise<SkillMarketListResult> {
+    const installed = await resolveInstalledSkillNames(installedSkillNames)
+    return {
+      ...result,
+      items: result.items.map((item): SkillMarketItem => ({
+        ...item,
+        installed: installed.has(item.slug),
+      })),
+    }
+  }
+
+  return {
+    listSkills,
+    list: listSkills,
+  }
+}
+
+async function requestJson(fetchImpl: FetchImpl, url: URL, sourceName: string): Promise<unknown> {
+  let response: Response
+  try {
+    response = await fetchImpl(url)
+  } catch (error) {
+    throw new Error(`${sourceName} request failed: ${errorMessage(error)}`)
+  }
+
+  if (!response.ok) {
+    throw new Error(`${sourceName} request failed with status ${response.status}`)
+  }
+
+  return response.json()
+}
+
+async function resolveInstalledSkillNames(provider?: InstalledSkillNamesProvider): Promise<Set<string>> {
+  if (!provider) {
+    return new Set()
+  }
+  if (provider instanceof Set) {
+    return provider
+  }
+  return provider()
+}
+
+function limitFor(limit: number | undefined): number {
+  if (!Number.isInteger(limit) || limit === undefined || limit < 1) {
+    return DEFAULT_LIMIT
+  }
+  return Math.min(limit, MAX_LIMIT)
+}
+
+function clawHubSort(sort: SkillMarketListParams['sort']): string {
+  if (sort === 'updated') {
+    return 'updated'
+  }
+  if (sort === 'installs' || sort === 'stars' || sort === 'trending') {
+    return sort
+  }
+  return 'downloads'
+}
+
+function skillHubSort(sort: SkillMarketListParams['sort']): string {
+  if (sort === 'updated') {
+    return 'updated_at'
+  }
+  if (sort === 'installs' || sort === 'stars') {
+    return sort
+  }
+  return 'downloads'
+}
+
+function addOptionalParam(url: URL, name: string, value: string | undefined) {
+  const trimmed = value?.trim()
+  if (trimmed) {
+    url.searchParams.set(name, trimmed)
+  }
+}
+
+function errorMessage(error: unknown): string {
+  return error instanceof Error ? error.message : String(error)
+}