feat(ai-chat): header badge shows current/max context, max from AI settings (#189)

The floating chat window's header badge flipped meaning — a live per-turn token
counter while streaming, the persisted context size at rest — so it "reset to 1"
on each prompt and conflated two different numbers. Replace it with a stable
"current / max" context badge (e.g. `572 / 200k`). The live "Thinking · N tokens"
inside the chat body stays; only the duplicate live counter is removed from the
header.

Max comes from a new admin setting "Context window (tokens)". The server resolves
it and attaches `maxContextTokens` to the completed assistant turn's metadata
(next to contextTokens), so the badge needs no client-side model resolution and
this survives public shares / per-role models.

Server:
- ai.types: chatContextWindow on AiProviderSettings + PROVIDER_SETTINGS_KEYS +
  ResolvedAiConfig + MaskedAiSettings.
- workspace.repo: chatContextWindow in AI_PROVIDER_SETTINGS_ALLOWED (parity).
- update-ai-settings.dto: @IsInt @Min(0) chatContextWindow.
- ai-settings.service: coerce the ::text-stored value to a positive int in
  resolve()/getMasked().
- ai-chat.service: flushAssistant writes metadata.maxContextTokens (>0); the
  completed turn passes resolved.chatContextWindow.

Client:
- ai-chat.types: maxContextTokens on the message-row metadata.
- ai-chat-window: read maxContextTokens; render "current [/ max]"; drop the
  liveTurnTokens state/branch and the onLiveTurnTokens prop; new tooltip.
- chat-thread: remove the live-turn-token throttle effect and plumbing.
- count-stream-tokens: drop the now-dead liveTurnTokens()/types; keep
  estimateTokens.
- settings: chatContextWindow on IAiSettings(+Update) + a NumberInput in the AI
  provider settings form.

i18n: add the badge/settings keys (en, ru); remove the two now-unused keys.
Tests: flushAssistant maxContextTokens, DTO validation, trim token tests.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/server/src/core/ai-chat/ai-chat.service.spec.ts

@@ -275,11 +275,12 @@ describe('flushAssistant', () => {
     expect(f.toolCalls).not.toBeNull();
   });
 
-  it('completed: attaches finishReason + normalized usage + contextTokens', () => {
+  it('completed: attaches finishReason + normalized usage + contextTokens + maxContextTokens', () => {
     const f = flushAssistant([toolStep], '', 'completed', {
       finishReason: 'stop',
       usage: { inputTokens: 10, outputTokens: 5, totalTokens: 15 },
       contextTokens: 15,
+      maxContextTokens: 200000,
     });
     expect(f.status).toBe('completed');
     expect(f.metadata.finishReason).toBe('stop');
@@ -290,6 +291,23 @@ describe('flushAssistant', () => {
       reasoningTokens: undefined,
     });
     expect(f.metadata.contextTokens).toBe(15);
+    expect(f.metadata.maxContextTokens).toBe(200000);
+  });
+
+  it('completed: omits maxContextTokens when unset or 0', () => {
+    // No maxContextTokens in the extra (admin set no context window).
+    const f = flushAssistant([toolStep], '', 'completed', {
+      finishReason: 'stop',
+      contextTokens: 15,
+    });
+    expect('maxContextTokens' in f.metadata).toBe(false);
+    // Explicit 0 is treated the same as unset (no limit -> key omitted).
+    const f0 = flushAssistant([toolStep], '', 'completed', {
+      finishReason: 'stop',
+      contextTokens: 15,
+      maxContextTokens: 0,
+    });
+    expect('maxContextTokens' in f0.metadata).toBe(false);
   });
 
   it('error: records the error and a derived finishReason', () => {

apps/server/src/core/ai-chat/ai-chat.service.ts

@@ -616,6 +616,10 @@ export class AiChatService implements OnModuleInit {
               contextTokens:
                 (usage?.inputTokens ?? 0) + (usage?.outputTokens ?? 0) ||
                 undefined,
+              // Max context window for the chat header badge denominator;
+              // resolved from the admin-configured provider settings (in
+              // closure scope here). Omitted/0 = no limit.
+              maxContextTokens: resolved?.chatContextWindow,
             }),
           );
           // Lifecycle: release the external MCP clients leased for this turn.
@@ -1212,8 +1216,9 @@ export async function applyFinalize(
  * `metadata.parts` is built by assistantParts over the finished steps, then the
  * in-progress text appended as a trailing text part, so rowToUiMessage /
  * findRecent keep replaying the turn unchanged. `metadata.finishReason`,
- * `metadata.error`, `metadata.usage` and `metadata.contextTokens` are attached
- * only when provided/relevant, matching the pre-#183 onFinish/onError records.
+ * `metadata.error`, `metadata.usage`, `metadata.contextTokens` and
+ * `metadata.maxContextTokens` are attached only when provided/relevant, matching
+ * the pre-#183 onFinish/onError records.
  */
 export function flushAssistant(
   capturedSteps: ReadonlyArray<StepLike> | undefined,
@@ -1223,6 +1228,7 @@ export function flushAssistant(
     finishReason?: string;
     usage?: ChatStreamUsage | StreamUsage | undefined;
     contextTokens?: number;
+    maxContextTokens?: number;
     error?: string;
   },
 ): AssistantFlush {
@@ -1253,6 +1259,8 @@ export function flushAssistant(
       normalizeStreamUsage(extra.usage as StreamUsage) ?? extra.usage;
   }
   if (extra?.contextTokens) metadata.contextTokens = extra.contextTokens;
+  if (extra?.maxContextTokens)
+    metadata.maxContextTokens = extra.maxContextTokens;
   if (extra?.error) metadata.error = extra.error;
 
   return {

apps/server/src/database/repos/workspace/workspace.repo.ts

@@ -20,6 +20,7 @@ import { DB, Workspaces } from '@docmost/db/types/db';
 export const AI_PROVIDER_SETTINGS_ALLOWED: readonly string[] = [
   'driver',
   'chatModel',
+  'chatContextWindow',
   'chatApiStyle',
   'embeddingModel',
   'baseUrl',

apps/server/src/integrations/ai/ai-provider-settings-keys.spec.ts

@@ -41,3 +41,35 @@ describe('UpdateAiSettingsDto.chatApiStyle', () => {
     expect(errs.find((e) => e.property === 'chatApiStyle')).toBeUndefined();
   });
 });
+
+/** DTO validation for the new chatContextWindow field (@IsInt @Min(0)). */
+describe('UpdateAiSettingsDto.chatContextWindow', () => {
+  const errorsFor = async (chatContextWindow: unknown) =>
+    validate(plainToInstance(UpdateAiSettingsDto, { chatContextWindow }));
+
+  it('accepts a non-negative integer (incl. 0 = clear the limit)', async () => {
+    for (const v of [0, 200000]) {
+      const errs = await errorsFor(v);
+      expect(
+        errs.find((e) => e.property === 'chatContextWindow'),
+      ).toBeUndefined();
+    }
+  });
+
+  it('rejects a negative value', async () => {
+    const errs = await errorsFor(-1);
+    expect(errs.find((e) => e.property === 'chatContextWindow')).toBeDefined();
+  });
+
+  it('rejects a non-integer value', async () => {
+    const errs = await errorsFor(1.5);
+    expect(errs.find((e) => e.property === 'chatContextWindow')).toBeDefined();
+  });
+
+  it('accepts the field being omitted (optional)', async () => {
+    const errs = await validate(plainToInstance(UpdateAiSettingsDto, {}));
+    expect(
+      errs.find((e) => e.property === 'chatContextWindow'),
+    ).toBeUndefined();
+  });
+});

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

@@ -26,6 +26,8 @@ import {
 export interface UpdateAiSettingsInput {
   driver?: AiDriver;
   chatModel?: string;
+  // Max context window in tokens for the chat header badge. 0/empty = no limit.
+  chatContextWindow?: number;
   chatApiStyle?: ChatApiStyle;
   embeddingModel?: string;
   baseUrl?: string;
@@ -157,9 +159,20 @@ export class AiSettingsService {
     const provider = await this.readProvider(workspaceId);
     if (!provider.driver) return null;
 
+    // Provider values are stored as ::text (see workspace.repo.ts), so
+    // chatContextWindow arrives as a string here; parse it back to a positive
+    // integer or undefined.
+    const ctxWindow = Number(provider.chatContextWindow);
+
     const config: ResolvedAiConfig = {
       driver: provider.driver,
       chatModel: provider.chatModel,
+      // Max context window for the chat header badge denominator. 0/unset = no
+      // limit.
+      chatContextWindow:
+        Number.isFinite(ctxWindow) && ctxWindow > 0
+          ? Math.floor(ctxWindow)
+          : undefined,
       // Plain passthrough; getChatModel defaults unset to 'openai-compatible'.
       chatApiStyle: provider.chatApiStyle,
       // Cheap model id for the anonymous public-share assistant; reuses the chat
@@ -219,6 +232,15 @@ export class AiSettingsService {
   async getMasked(workspaceId: string): Promise<MaskedAiSettings> {
     const provider = await this.readProvider(workspaceId);
 
+    // Provider values are stored as ::text (see workspace.repo.ts), so
+    // chatContextWindow arrives as a string; coerce it to a positive integer or
+    // undefined so the client receives a real number.
+    const ctxWindow = Number(provider.chatContextWindow);
+    const chatContextWindow =
+      Number.isFinite(ctxWindow) && ctxWindow > 0
+        ? Math.floor(ctxWindow)
+        : undefined;
+
     let hasApiKey = false;
     let hasEmbeddingApiKey = false;
     let hasSttApiKey = false;
@@ -243,6 +265,7 @@ export class AiSettingsService {
     return {
       driver: provider.driver,
       chatModel: provider.chatModel,
+      chatContextWindow,
       chatApiStyle: provider.chatApiStyle,
       embeddingModel: provider.embeddingModel,
       baseUrl: provider.baseUrl,

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

@@ -32,6 +32,9 @@ export const CHAT_API_STYLES: ChatApiStyle[] = ['openai-compatible', 'openai'];
 export interface AiProviderSettings {
   driver: AiDriver;
   chatModel: string;
+  // Max context window in tokens; surfaced to the chat header badge as the
+  // denominator ("current / max"). 0/unset = no limit (badge shows no denominator).
+  chatContextWindow?: number;
   // Chat provider implementation for the `openai` driver. Unset → defaults to
   // 'openai-compatible' (so reasoning is surfaced by default). See ChatApiStyle.
   chatApiStyle?: ChatApiStyle;
@@ -72,6 +75,7 @@ export interface AiProviderSettings {
 export const PROVIDER_SETTINGS_KEYS = [
   'driver',
   'chatModel',
+  'chatContextWindow',
   'chatApiStyle',
   'embeddingModel',
   'baseUrl',
@@ -98,6 +102,9 @@ export const PROVIDER_SETTINGS_KEYS = [
 export interface ResolvedAiConfig extends Partial<AiProviderSettings> {
   driver?: AiDriver;
   chatModel?: string;
+  // Max context window in tokens; surfaced to the chat header badge as the
+  // "current / max" denominator. 0/unset = no limit.
+  chatContextWindow?: number;
   // Cheap model id for the public-share assistant; reuses the chat creds.
   publicShareChatModel?: string;
   // Agent-role id whose persona the public-share assistant adopts (empty/unset
@@ -116,6 +123,9 @@ export interface ResolvedAiConfig extends Partial<AiProviderSettings> {
 export interface MaskedAiSettings {
   driver?: AiDriver;
   chatModel?: string;
+  // Max context window in tokens; the chat header badge denominator. 0/unset =
+  // no limit.
+  chatContextWindow?: number;
   chatApiStyle?: ChatApiStyle;
   embeddingModel?: string;
   baseUrl?: string;

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

@@ -1,4 +1,4 @@
-import { IsIn, IsOptional, IsString } from 'class-validator';
+import { IsIn, IsInt, IsOptional, IsString, Min } from 'class-validator';
 import {
   AI_DRIVERS,
   AiDriver,
@@ -25,6 +25,13 @@ export class UpdateAiSettingsDto {
   @IsString()
   chatModel?: string;
 
+  // Max context window in tokens shown in the chat header badge. 0/empty =
+  // clear the limit (no denominator shown).
+  @IsOptional()
+  @IsInt()
+  @Min(0)
+  chatContextWindow?: number;
+
   @IsOptional()
   @IsIn(CHAT_API_STYLES)
   chatApiStyle?: ChatApiStyle;