feat(ai-chat): explicit chatApiStyle selector to surface reasoning (#175)

Rebuilt on develop (after #176) and reworked per review: instead of inferring the
provider from baseUrl (`if (baseUrl)`), the admin picks the chat provider
EXPLICITLY via a new `chatApiStyle` ('openai-compatible' | 'openai'), mirroring
the existing sttApiStyle. A custom baseURL can front real OpenAI too, so the
heuristic was fragile.

Why reasoning was missing: glm-5.2 (and DeepSeek etc.) stream their thinking as
`reasoning_content`, but the official @ai-sdk/openai provider does not map that
field. 'openai-compatible' uses @ai-sdk/openai-compatible, which does — so
reasoning parts now stream (verified live: reasoning-start/delta/end appear, and
disappear when set to 'openai').

- Default (unset) = 'openai-compatible', so existing openai+baseUrl workspaces
  surface reasoning with no admin action. No DB migration (field lives in the
  settings.ai.provider JSON blob).
- includeUsage: true on the openai-compatible model — without it the provider
  omits streamed usage, zeroing the live token counter / reasoning-token
  metadata. The official provider always sent it; this keeps parity. (Confirmed
  live: usage.totalTokens present.)
- openai-compatible has no default endpoint, so with no baseURL (real OpenAI, or
  a role's cross-driver override that cleared it) it falls back to the official
  provider.

Plumbing: ai.types (ChatApiStyle / CHAT_API_STYLES + AiProviderSettings /
MaskedAiSettings), update DTO (@IsIn), ai-settings.service (resolve / getMasked /
update allowlist), workspace.repo updateAiProviderSettings ALLOWED (the second,
SQL-level allowlist the review missed — without it the field never persisted),
ai.service selector. Client: ai-settings-service types + a Protocol <Select> in
the chat section + i18n (en/ru). Scope is chat-only (embeddings don't stream
reasoning; STT already has sttApiStyle).

Tests: ai.service.spec — 4 cases (openai-compatible+baseURL, openai+baseURL,
default-unset, openai-compatible-without-baseURL fallback). Verified on the stand:
default streams reasoning + usage; 'openai' drops reasoning; the setting
round-trips. server + client tsc clean; 36 ai/settings specs green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/src/integrations/ai/ai-settings.service.ts

@@ -14,6 +14,7 @@ import {
   MaskedAiSettings,
   ResolvedAiConfig,
   SttApiStyle,
+  ChatApiStyle,
 } from './ai.types';
 
 /**
@@ -24,6 +25,7 @@ import {
 export interface UpdateAiSettingsInput {
   driver?: AiDriver;
   chatModel?: string;
+  chatApiStyle?: ChatApiStyle;
   embeddingModel?: string;
   baseUrl?: string;
   embeddingBaseUrl?: string;
@@ -157,6 +159,8 @@ export class AiSettingsService {
     const config: ResolvedAiConfig = {
       driver: provider.driver,
       chatModel: provider.chatModel,
+      // Plain passthrough; getChatModel defaults unset to 'openai-compatible'.
+      chatApiStyle: provider.chatApiStyle,
       // Cheap model id for the anonymous public-share assistant; reuses the chat
       // driver/baseUrl/apiKey. Empty/unset → callers fall back to chatModel.
       publicShareChatModel: provider.publicShareChatModel,
@@ -238,6 +242,7 @@ export class AiSettingsService {
     return {
       driver: provider.driver,
       chatModel: provider.chatModel,
+      chatApiStyle: provider.chatApiStyle,
       embeddingModel: provider.embeddingModel,
       baseUrl: provider.baseUrl,
       embeddingBaseUrl: provider.embeddingBaseUrl,
@@ -278,6 +283,7 @@ export class AiSettingsService {
     for (const key of [
       'driver',
       'chatModel',
+      'chatApiStyle',
       'embeddingModel',
       'baseUrl',
       'embeddingBaseUrl',

apps/server/src/integrations/ai/ai.service.spec.ts

@@ -285,3 +285,64 @@ describe('AiService.getChatModel role model override', () => {
     );
   });
 });
+
+/**
+ * Chat provider selection by the EXPLICIT `chatApiStyle` (NOT inferred from
+ * baseUrl): 'openai-compatible' (default) uses @ai-sdk/openai-compatible, which
+ * maps streamed reasoning_content to reasoning parts; 'openai' uses the official
+ * provider; and openai-compatible without a baseURL safely falls back to the
+ * official provider (it has no default endpoint). Asserted via `.provider`.
+ */
+describe('AiService.getChatModel chatApiStyle provider selection', () => {
+  function serviceWith(opts: {
+    baseUrl?: string;
+    chatApiStyle?: 'openai-compatible' | 'openai';
+  }) {
+    const aiSettings = {
+      resolve: jest.fn().mockResolvedValue({
+        driver: 'openai',
+        chatModel: 'glm-5.2',
+        apiKey: 'key',
+        baseUrl: opts.baseUrl,
+        chatApiStyle: opts.chatApiStyle,
+      }),
+    };
+    return new AiService(
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      aiSettings as any,
+      { find: jest.fn() } as never,
+      { decryptSecret: jest.fn() } as never,
+    );
+  }
+
+  const providerOf = async (svc: AiService) =>
+    (
+      (await svc.getChatModel('ws-1')) as { provider: string }
+    ).provider;
+
+  it("'openai-compatible' + baseURL -> openai-compatible provider", async () => {
+    expect(
+      await providerOf(
+        serviceWith({ baseUrl: 'https://api.z.ai/v4', chatApiStyle: 'openai-compatible' }),
+      ),
+    ).toContain('openai-compatible');
+  });
+
+  it("'openai' + baseURL -> official openai provider", async () => {
+    expect(
+      await providerOf(serviceWith({ baseUrl: 'https://api.z.ai/v4', chatApiStyle: 'openai' })),
+    ).toBe('openai.chat');
+  });
+
+  it('unset + baseURL -> defaults to openai-compatible', async () => {
+    expect(
+      await providerOf(serviceWith({ baseUrl: 'https://api.z.ai/v4' })),
+    ).toContain('openai-compatible');
+  });
+
+  it("'openai-compatible' WITHOUT baseURL -> safe fallback to official openai", async () => {
+    expect(
+      await providerOf(serviceWith({ chatApiStyle: 'openai-compatible' })),
+    ).toBe('openai.chat');
+  });
+});

apps/server/src/integrations/ai/ai.service.ts

@@ -7,6 +7,7 @@ import {
   type LanguageModel,
 } from 'ai';
 import { createOpenAI } from '@ai-sdk/openai';
+import { createOpenAICompatible } from '@ai-sdk/openai-compatible';
 import { createGoogleGenerativeAI } from '@ai-sdk/google';
 import { createOllama } from 'ai-sdk-ollama';
 import { AiSettingsService } from './ai-settings.service';
@@ -95,6 +96,10 @@ export class AiService {
 
     let apiKey = cfg.apiKey;
     let baseUrl = cfg.baseUrl;
+    // Chat provider implementation, chosen EXPLICITLY by the admin (not inferred
+    // from baseUrl). Unset → 'openai-compatible' so reasoning is surfaced by
+    // default for this fork's openai+baseUrl setups.
+    const chatApiStyle = cfg.chatApiStyle ?? 'openai-compatible';
 
     // A driver override that differs from the workspace driver needs that
     // driver's own creds (the workspace driver's key would be wrong/absent).
@@ -145,19 +150,41 @@ export class AiService {
     }
 
     switch (driver) {
-      case 'openai':
-        // baseURL (when set) covers openai-compatible endpoints. Use Chat
-        // Completions (/chat/completions) — the portable OpenAI-compatible
-        // endpoint. The default callable createOpenAI(...)(model) targets the
-        // Responses API (/responses), which OpenAI-compatible gateways
-        // (OpenRouter, etc.) reject on multi-turn requests (history with
-        // assistant messages) → 400. The provider fetch is the instrumented
-        // streaming fetch (finite-but-generous stream timeouts, #175).
+      case 'openai': {
+        // The provider implementation is chosen by the admin's `chatApiStyle`
+        // (NOT inferred from baseUrl — a custom URL can front real OpenAI too).
+        // Both branches hit Chat Completions (/chat/completions); the provider
+        // fetch is the instrumented streaming fetch (finite-but-generous stream
+        // timeouts, #175).
+        //
+        // 'openai-compatible' (default) maps the third-party provider's streamed
+        // `reasoning_content` to reasoning parts (z.ai/GLM, DeepSeek, ...) — the
+        // point of #175. It has no default endpoint, so it requires a baseURL;
+        // when there is none (real OpenAI, or a role's cross-driver override that
+        // cleared baseUrl) we fall back to the official provider.
+        if (chatApiStyle === 'openai-compatible' && baseUrl) {
+          return createOpenAICompatible({
+            name: 'openai-compatible',
+            apiKey,
+            baseURL: baseUrl,
+            // Keep streamed token usage (stream_options.include_usage): without
+            // it @ai-sdk/openai-compatible omits usage, zeroing the live token
+            // counter and reasoning-token metadata. The official provider always
+            // sent it, so this preserves parity.
+            includeUsage: true,
+            fetch: this.aiProviderFetch,
+          })(chatModel);
+        }
+        // Official @ai-sdk/openai: real-OpenAI reasoning-model request shaping;
+        // `.chat()` targets Chat Completions (the default callable targets the
+        // Responses API, which openai-compatible gateways 400 on multi-turn
+        // history). In this fork baseUrl is normally set; undefined = real OpenAI.
         return createOpenAI({
           apiKey,
           baseURL: baseUrl,
           fetch: this.aiProviderFetch,
         }).chat(chatModel);
+      }
       case 'gemini':
         return createGoogleGenerativeAI({ apiKey })(chatModel);
       case 'ollama':

apps/server/src/integrations/ai/ai.types.ts

@@ -16,6 +16,15 @@ export const AI_DRIVERS: AiDriver[] = ['openai', 'gemini', 'ollama'];
 export type SttApiStyle = 'multipart' | 'json';
 export const STT_API_STYLES: SttApiStyle[] = ['multipart', 'json'];
 
+// Chat provider implementation for the `openai` driver. Chosen explicitly by the
+// admin (NOT inferred from baseUrl — a custom URL can front real OpenAI too).
+// 'openai-compatible' = @ai-sdk/openai-compatible: maps streamed
+//   `reasoning_content` to reasoning parts (z.ai/GLM, DeepSeek, OpenRouter, ...).
+// 'openai' = official @ai-sdk/openai: real-OpenAI reasoning-model request shaping
+//   (max_completion_tokens, the 'developer' role), no third-party reasoning map.
+export type ChatApiStyle = 'openai-compatible' | 'openai';
+export const CHAT_API_STYLES: ChatApiStyle[] = ['openai-compatible', 'openai'];
+
 /**
  * Non-secret provider settings persisted under `settings.ai.provider`.
  * The API key is intentionally absent here.
@@ -23,6 +32,9 @@ export const STT_API_STYLES: SttApiStyle[] = ['multipart', 'json'];
 export interface AiProviderSettings {
   driver: AiDriver;
   chatModel: string;
+  // Chat provider implementation for the `openai` driver. Unset → defaults to
+  // 'openai-compatible' (so reasoning is surfaced by default). See ChatApiStyle.
+  chatApiStyle?: ChatApiStyle;
   embeddingModel?: string;
   baseUrl?: string;
   // Embedding-specific base URL. Falls back to `baseUrl` when empty/unset.
@@ -76,6 +88,7 @@ export interface ResolvedAiConfig extends Partial<AiProviderSettings> {
 export interface MaskedAiSettings {
   driver?: AiDriver;
   chatModel?: string;
+  chatApiStyle?: ChatApiStyle;
   embeddingModel?: string;
   baseUrl?: string;
   embeddingBaseUrl?: string;

apps/server/src/integrations/ai/dto/update-ai-settings.dto.ts

@@ -1,5 +1,12 @@
 import { IsIn, IsOptional, IsString } from 'class-validator';
-import { AI_DRIVERS, AiDriver, STT_API_STYLES, SttApiStyle } from '../ai.types';
+import {
+  AI_DRIVERS,
+  AiDriver,
+  CHAT_API_STYLES,
+  ChatApiStyle,
+  STT_API_STYLES,
+  SttApiStyle,
+} from '../ai.types';
 
 /**
  * Admin update payload for the workspace AI provider settings.
@@ -18,6 +25,10 @@ export class UpdateAiSettingsDto {
   @IsString()
   chatModel?: string;
 
+  @IsOptional()
+  @IsIn(CHAT_API_STYLES)
+  chatApiStyle?: ChatApiStyle;
+
   @IsOptional()
   @IsString()
   embeddingModel?: string;