diff --git a/src/main/apiServer/utils/__tests__/provider-alias.test.ts b/src/main/apiServer/utils/__tests__/provider-alias.test.ts
new file mode 100644
index 0000000000..d7aad83b23
--- /dev/null
+++ b/src/main/apiServer/utils/__tests__/provider-alias.test.ts
@@ -0,0 +1,118 @@
+import { CacheService } from '@main/services/CacheService'
+import type { Model, Provider } from '@types'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const { selectMock } = vi.hoisted(() => ({
+  selectMock: vi.fn()
+}))
+
+vi.mock('@main/services/ReduxService', () => ({
+  reduxService: {
+    select: selectMock
+  }
+}))
+
+import { getProviderByModel, transformModelToOpenAI, validateModelId } from '..'
+
+describe('api server provider alias', () => {
+  beforeEach(() => {
+    CacheService.clear()
+    selectMock.mockReset()
+  })
+
+  it('formats model id using provider apiIdentifier when present', () => {
+    const provider: Provider = {
+      id: 'test-provider-uuid',
+      apiIdentifier: 'short',
+      type: 'openai',
+      name: 'Custom Provider',
+      apiKey: 'test-key',
+      apiHost: 'https://example.com/v1',
+      models: [],
+      enabled: true
+    }
+
+    const model: Model = {
+      id: 'glm-4.6',
+      provider: provider.id,
+      name: 'glm-4.6',
+      group: 'glm'
+    }
+
+    const apiModel = transformModelToOpenAI(model, provider)
+    expect(apiModel.id).toBe('short:glm-4.6')
+    expect(apiModel.provider).toBe('test-provider-uuid')
+  })
+
+  it('resolves provider by apiIdentifier for model routing', async () => {
+    const provider: Provider = {
+      id: 'test-provider-uuid',
+      apiIdentifier: 'short',
+      type: 'openai',
+      name: 'Custom Provider',
+      apiKey: 'test-key',
+      apiHost: 'https://example.com/v1',
+      models: [],
+      enabled: true
+    }
+
+    selectMock.mockResolvedValue([provider])
+
+    const resolved = await getProviderByModel('short:glm-4.6')
+    expect(resolved?.id).toBe('test-provider-uuid')
+  })
+
+  it('validates model ids with apiIdentifier prefix', async () => {
+    const provider: Provider = {
+      id: 'test-provider-uuid',
+      apiIdentifier: 'short',
+      type: 'openai',
+      name: 'Custom Provider',
+      apiKey: 'test-key',
+      apiHost: 'https://example.com/v1',
+      models: [
+        {
+          id: 'glm-4.6',
+          provider: 'test-provider-uuid',
+          name: 'glm-4.6',
+          group: 'glm'
+        }
+      ],
+      enabled: true
+    }
+
+    selectMock.mockResolvedValue([provider])
+
+    const result = await validateModelId('short:glm-4.6')
+    expect(result.valid).toBe(true)
+    expect(result.provider?.id).toBe('test-provider-uuid')
+    expect(result.modelId).toBe('glm-4.6')
+  })
+
+  it('still supports provider.id prefix', async () => {
+    const provider: Provider = {
+      id: 'test-provider-uuid',
+      apiIdentifier: 'short',
+      type: 'openai',
+      name: 'Custom Provider',
+      apiKey: 'test-key',
+      apiHost: 'https://example.com/v1',
+      models: [
+        {
+          id: 'glm-4.6',
+          provider: 'test-provider-uuid',
+          name: 'glm-4.6',
+          group: 'glm'
+        }
+      ],
+      enabled: true
+    }
+
+    selectMock.mockResolvedValue([provider])
+
+    const result = await validateModelId('test-provider-uuid:glm-4.6')
+    expect(result.valid).toBe(true)
+    expect(result.provider?.id).toBe('test-provider-uuid')
+    expect(result.modelId).toBe('glm-4.6')
+  })
+})
diff --git a/src/main/apiServer/utils/index.ts b/src/main/apiServer/utils/index.ts
index e25b49e750..072d9ecf54 100644
--- a/src/main/apiServer/utils/index.ts
+++ b/src/main/apiServer/utils/index.ts
@@ -82,16 +82,24 @@ export async function getProviderByModel(model: string): Promise<Provider | unde
     }
 
     const providerId = modelInfo[0]
-    const provider = providers.find((p: Provider) => p.id === providerId)
+    const matchingProviders = providers.filter((p: Provider) => p.id === providerId || p.apiIdentifier === providerId)
+    const provider = matchingProviders.find((p) => p.id === providerId) ?? matchingProviders[0]
 
     if (!provider) {
       logger.warn('Provider not found for model', {
         providerId,
-        available: providers.map((p) => p.id)
+        available: providers.map((p) => ({ id: p.id, apiIdentifier: p.apiIdentifier }))
       })
       return undefined
     }
 
+    if (matchingProviders.length > 1) {
+      logger.warn('Multiple providers matched for model prefix', {
+        providerId,
+        matches: matchingProviders.map((p) => ({ id: p.id, apiIdentifier: p.apiIdentifier }))
+      })
+    }
+
     logger.debug('Provider resolved for model', { providerId, model })
     return provider
   } catch (error: any) {
@@ -200,8 +208,9 @@ export async function validateModelId(model: string): Promise<{
 
 export function transformModelToOpenAI(model: Model, provider?: Provider): ApiModel {
   const providerDisplayName = provider?.name
+  const providerModelPrefix = provider?.apiIdentifier?.trim() || provider?.id || model.provider
   return {
-    id: `${model.provider}:${model.id}`,
+    id: `${providerModelPrefix}:${model.id}`,
     object: 'model',
     name: model.name,
     created: Math.floor(Date.now() / 1000),
diff --git a/src/renderer/src/types/provider.ts b/src/renderer/src/types/provider.ts
index edab3a7305..313e0eb7a2 100644
--- a/src/renderer/src/types/provider.ts
+++ b/src/renderer/src/types/provider.ts
@@ -98,6 +98,11 @@ export type Provider = {
   id: string
   type: ProviderType
   name: string
+  /**
+   * Optional short identifier used by the built-in API relay.
+   * When set, models can be referenced as `${apiIdentifier}:${modelId}` instead of `${id}:${modelId}`.
+   */
+  apiIdentifier?: string
   apiKey: string
   apiHost: string
   anthropicApiHost?: string