feat(ai): add OpenRouter provider

docs/website/.vitepress/components/home/HomeAi.vue

@@ -74,9 +74,10 @@ const workflows = [
       <div>
         <h3>Your choice of model.</h3>
         <p>
-          Connect OpenAI, Anthropic, Gemini, DeepSeek, Mistral, or xAI with your
-          own API key. Or use a model running on your computer with Ollama or LM
-          Studio. Cloud API usage is billed by your provider.
+          Connect OpenAI, Anthropic, Gemini, DeepSeek, Mistral, xAI, or
+          OpenRouter with your own API key. Or use a model running on your
+          computer with Ollama or LM Studio. Cloud API usage is billed by your
+          provider.
         </p>
       </div>
       <div>

docs/website/documentation/ai.md

@@ -16,6 +16,7 @@ Open **Preferences → AI assistant** and choose a provider.
 | Provider | Connection |
 | --- | --- |
 | OpenAI, Anthropic, Google Gemini, DeepSeek, Mistral, xAI | Enter your provider API key. Requests use that provider’s API account and billing. |
+| OpenRouter | Enter your OpenRouter API key. Requests use your OpenRouter account and billing. The model list includes only models with tool calling support; IDs use the `vendor/model` format, for example `anthropic/claude-sonnet-5.5`. |
 | Ollama | Start the server and enter its API address, usually `http://localhost:11434/v1`. |
 | LM Studio | Start its API server and enter the address, usually `http://localhost:1234/v1`. Enter a key if the server requires one. |
 

package.json

@@ -84,6 +84,7 @@
     "@lezer/markdown": "^1.6.3",
     "@lydell/node-pty": "^1.1.0",
     "@modelcontextprotocol/server": "^2.0.0",
+    "@openrouter/ai-sdk-provider": "^2.10.0",
     "@sinclair/typebox": "^0.34.41",
     "@types/d3-force": "^3.0.10",
     "@types/d3-scale": "^4.0.9",

src/main/ai/__tests__/sdk.test.ts

@@ -1,6 +1,11 @@
 import { afterEach, expect, it, vi } from 'vitest'
 import { AI_DEFAULT_URLS, aiMessageSchema } from '../../../shared/ai'
-import { generateAiResponse, listAiModels, streamAiChat } from '../client'
+import {
+  checkResponse,
+  generateAiResponse,
+  listAiModels,
+  streamAiChat,
+} from '../client'
 import { sdkMessages } from '../sdk'
 import { wireResponse as response } from './fixtures/aiWire'
 
@@ -10,6 +15,7 @@ const providers = [
   'deepseek',
   'mistral',
   'xai',
+  'openrouter',
 ] as const
 const tool = {
   type: 'function',
@@ -65,6 +71,162 @@ it.each(providers)(
     expect(fetcher.mock.calls[0][1].redirect).toBe('error')
   },
 )
+it('openrouter completes a tool loop after unsigned reasoning deltas', async () => {
+  const chunk = (delta: object, finish_reason: string | null = null) => ({
+    id: 'msg1',
+    model: 'test',
+    created: 1,
+    choices: [{ index: 0, delta, finish_reason }],
+  })
+  const reasoning = (text: string) =>
+    chunk({
+      role: 'assistant',
+      reasoning_details: [
+        { type: 'reasoning.text', text, format: 'unknown', index: 0 },
+      ],
+    })
+  const wire = [
+    reasoning('Думаю'),
+    reasoning(' дальше'),
+    chunk({
+      tool_calls: [
+        {
+          index: 0,
+          id: 'call12345',
+          type: 'function',
+          function: { name: 'read_http_context', arguments: '{}' },
+        },
+      ],
+    }),
+    chunk({}, 'tool_calls'),
+  ]
+    .map(event => `data: ${JSON.stringify(event)}\n\n`)
+    .join('')
+  const fetcher = vi
+    .fn()
+    .mockImplementationOnce(
+      async () =>
+        new Response(`${wire}data: [DONE]\n\n`, {
+          headers: { 'content-type': 'text/event-stream' },
+        }),
+    )
+    .mockImplementationOnce(async () => response('openrouter'))
+  vi.stubGlobal('fetch', fetcher)
+  const execute = vi.fn(async () => ({ status: 200, body: { id: 42 } }))
+  let answer = ''
+  await streamAiChat(
+    {
+      provider: 'openrouter',
+      baseURL: AI_DEFAULT_URLS.openrouter,
+      model: 'test',
+      apiKey: 'synthetic',
+    },
+    [{ role: 'user', content: 'Разбери ответ' }],
+    new AbortController().signal,
+    (text) => {
+      answer += text
+    },
+    undefined,
+    undefined,
+    1,
+    0,
+    undefined,
+    undefined,
+    { tools: [tool], execute, remaining: 3 },
+  )
+  expect(answer).toBe('Ответ 😀')
+  expect(execute).toHaveBeenCalledExactlyOnceWith('read_http_context', '{}')
+  const second = JSON.stringify(JSON.parse(fetcher.mock.calls[1][1].body))
+  expect(second).toContain('reasoning_details')
+  expect(second).toContain('Думаю дальше')
+})
+it('openrouter keeps unsigned reasoning when the answer has no tool call', async () => {
+  const chunk = (delta: object, finish_reason: string | null = null) => ({
+    id: 'msg1',
+    model: 'test',
+    created: 1,
+    choices: [{ index: 0, delta, finish_reason }],
+  })
+  const reasoning = (text: string) =>
+    chunk({
+      role: 'assistant',
+      reasoning_details: [
+        { type: 'reasoning.text', text, format: 'unknown', index: 0 },
+      ],
+    })
+  const wire = [
+    reasoning('Думаю'),
+    reasoning(' дальше'),
+    chunk({ content: 'Ответ' }),
+    chunk({}, 'stop'),
+  ]
+    .map(event => `data: ${JSON.stringify(event)}\n\n`)
+    .join('')
+  vi.stubGlobal(
+    'fetch',
+    vi.fn(
+      async () =>
+        new Response(`${wire}data: [DONE]\n\n`, {
+          headers: { 'content-type': 'text/event-stream' },
+        }),
+    ),
+  )
+  const result = await generateAiResponse(
+    {
+      provider: 'openrouter',
+      baseURL: AI_DEFAULT_URLS.openrouter,
+      model: 'test',
+      apiKey: 'synthetic',
+    },
+    {
+      instructions: 'test',
+      messages: [{ role: 'user', content: 'hello' }],
+      signal: new AbortController().signal,
+      onDelta: () => {},
+      operation: 'test',
+    },
+  )
+  expect(result.answer).toBe('Ответ')
+  expect(result.calls).toEqual([])
+  expect(JSON.stringify(result.replay)).toContain('Думаю дальше')
+})
+it.each(providers)(
+  '%s maps exhausted credits to the quota error',
+  async (provider) => {
+    vi.stubGlobal(
+      'fetch',
+      vi.fn(
+        async () =>
+          new Response(
+            JSON.stringify({ error: { message: 'Insufficient credits' } }),
+            { status: 402, headers: { 'content-type': 'application/json' } },
+          ),
+      ),
+    )
+    await expect(
+      generateAiResponse(
+        {
+          provider,
+          baseURL: AI_DEFAULT_URLS[provider],
+          model: 'test',
+          apiKey: 'synthetic',
+        },
+        {
+          instructions: 'test',
+          messages: [{ role: 'user', content: 'hello' }],
+          signal: new AbortController().signal,
+          onDelta: () => {},
+          operation: 'test',
+        },
+      ),
+    ).rejects.toMatchObject({ code: 'rateLimit' })
+  },
+)
+it('maps exhausted credits to the quota error for direct HTTP providers', async () => {
+  await expect(
+    checkResponse(new Response('{}', { status: 402 })),
+  ).rejects.toMatchObject({ code: 'rateLimit' })
+})
 it.each(providers)(
   '%s maps authentication failure without retry or leaking body',
   async (provider) => {
@@ -220,6 +382,60 @@ it('lists Anthropic models using native authentication and pagination', async ()
     '2023-06-01',
   )
 })
+it('lists only tool-capable OpenRouter chat models', async () => {
+  const fetcher = vi
+    .fn()
+    .mockResolvedValueOnce(new Response(JSON.stringify({ data: {} })))
+    .mockResolvedValueOnce(
+      new Response(
+        JSON.stringify({
+          data: [{ id: 'b/model' }, { id: 'a/model' }, { id: 'a/model:batch' }],
+        }),
+      ),
+    )
+  vi.stubGlobal('fetch', fetcher)
+  expect(
+    await listAiModels(
+      {
+        provider: 'openrouter',
+        baseURL: AI_DEFAULT_URLS.openrouter,
+        model: '',
+        apiKey: 'synthetic',
+      },
+      new AbortController().signal,
+    ),
+  ).toEqual(['a/model', 'b/model'])
+  expect(fetcher.mock.calls[0][0]).toBe('https://openrouter.ai/api/v1/key')
+  expect(fetcher.mock.calls[0][1].headers.Authorization).toBe(
+    'Bearer synthetic',
+  )
+  expect(fetcher.mock.calls[1][0]).toBe(
+    'https://openrouter.ai/api/v1/models?supported_parameters=tools',
+  )
+})
+it('rejects an invalid OpenRouter key before listing public models', async () => {
+  const fetcher = vi
+    .fn()
+    .mockResolvedValueOnce(
+      new Response(
+        JSON.stringify({ error: { message: 'User not found.', code: 401 } }),
+        { status: 401 },
+      ),
+    )
+  vi.stubGlobal('fetch', fetcher)
+  await expect(
+    listAiModels(
+      {
+        provider: 'openrouter',
+        baseURL: AI_DEFAULT_URLS.openrouter,
+        model: '',
+        apiKey: 'invalid',
+      },
+      new AbortController().signal,
+    ),
+  ).rejects.toMatchObject({ code: 'authentication' })
+  expect(fetcher).toHaveBeenCalledOnce()
+})
 it.each(providers)(
   '%s rejects an empty/incomplete stream',
   async (provider) => {

src/main/ai/__tests__/settings.test.ts

@@ -206,6 +206,7 @@ it('pins cloud credentials to official provider endpoints', async () => {
     'deepseek',
     'mistral',
     'xai',
+    'openrouter',
   ] as const) {
     expect(() =>
       canonicalAiURL(provider, 'https://unrelated.invalid/v1'),

src/main/ai/client.ts

@@ -94,7 +94,7 @@ export async function checkResponse(response: Response) {
   const code
     = response.status === 401 || response.status === 403
       ? 'authentication'
-      : response.status === 429
+      : response.status === 429 || response.status === 402
         ? 'rateLimit'
         : response.status === 404
           ? 'modelUnavailable'
@@ -205,7 +205,20 @@ export async function listAiModels(
 ): Promise<string[]> {
   if (page >= 20)
     throw new AiError('outputLimit')
+  // OpenRouter serves /models without authentication, so it cannot confirm the key.
+  if (connection.provider === 'openrouter' && !cursor) {
+    const keyResponse = await fetch(`${connection.baseURL}/key`, {
+      headers: headers(connection),
+      redirect: 'error',
+      signal,
+    })
+    await checkResponse(keyResponse)
+    await keyResponse.body?.cancel().catch(() => {})
+  }
   const url = new URL(`${connection.baseURL}/models`)
+  // The full OpenRouter catalog includes models that cannot run the assistant's tools.
+  if (connection.provider === 'openrouter')
+    url.searchParams.set('supported_parameters', 'tools')
   if (cursor) {
     url.searchParams.set(
       connection.provider === 'gemini' ? 'pageToken' : 'after_id',
@@ -249,6 +262,9 @@ export async function listAiModels(
     else {
       const parsed = modelsSchema.parse(JSON.parse(body))
       names = parsed.data.map(model => model.id)
+      // Batch variants are not served by chat completions and fail with 404.
+      if (connection.provider === 'openrouter')
+        names = names.filter(name => !name.endsWith(':batch'))
       if (connection.provider === 'anthropic' && parsed.has_more) {
         if (!parsed.last_id)
           throw new AiError('invalidResponse')