feat(inspector): say what the context is full of, not just how full

apps/desktop/src/main/__tests__/use-session-trace.test.ts

@@ -38,6 +38,7 @@ function trace(sessionId: string): SessionTrace {
 
 interface TraceHarness {
   reads: string[];
+  contextReads: string[];
   emit: (event: SessionEvent) => void;
   subscriptions: number;
   unsubscribes: number;
@@ -47,6 +48,7 @@ function installMakaBridge(): TraceHarness {
   const handlers = new Set<(event: SessionEvent) => void>();
   const harness: TraceHarness = {
     reads: [],
+    contextReads: [],
     emit: (event) => {
       for (const handler of [...handlers]) handler(event);
     },
@@ -61,6 +63,13 @@ function installMakaBridge(): TraceHarness {
           harness.reads.push(sessionId);
           return { ok: true, data: trace(sessionId) };
         },
+        // The hook reads the context snapshot on the same signal (#2323). It
+        // is counted separately: the assertions below are about how often the
+        // TRACE is re-read, and an enrichment read must not move them.
+        context: async (sessionId: string) => {
+          harness.contextReads.push(sessionId);
+          return { ok: true as const, data: { status: 'unavailable' as const, reason: 'no_completed_request' as const } };
+        },
       },
       sessions: {
         subscribeEvents: (_sessionId: string, handler: (event: SessionEvent) => void) => {

apps/desktop/src/main/runtime-host-renderer-ipc-main.ts

@@ -69,6 +69,8 @@ function request(
   value: unknown,
 ): Promise<unknown> {
   switch (operation) {
+    case 'context.diagnostics.query':
+      return client.request(operation, HOST_OPERATION_SPECS[operation].decodeInput(value));
     case 'daily-review.mutate':
       return client.request(operation, HOST_OPERATION_SPECS[operation].decodeInput(value));
     case 'daily-review.query':

apps/desktop/src/preload/bridge-contract.d.ts

@@ -87,6 +87,7 @@ import type {
   RendererRuntimeHostQueryOperation,
 } from './runtime-host-renderer-operations.js';
 import type { SessionTrace } from '@maka/core/session-trace';
+import type { ContextDiagnosticsResult } from '@maka/runtime-host/protocol';
 import type { TestProxyInput } from '@maka/core/settings/network-settings';
 import type { ExternalSessionImportIpcResult } from './external-session-import-result.js';
 import type {
@@ -803,6 +804,8 @@ export interface MakaBridge {
   inspector: {
     /** Read-only per-session causal trace (#1625). */
     trace(sessionId: string): Promise<Result<SessionTrace>>;
+    /** What the session's context is made of right now (#2323). */
+    context(sessionId: string): Promise<Result<ContextDiagnosticsResult>>;
   };
   webSearch: {
     query(input: {

apps/desktop/src/preload/preload.ts

@@ -110,6 +110,7 @@ import {
   isSessionTrace,
   type SessionTrace,
 } from '@maka/core/session-trace';
+import type { ContextDiagnosticsResult } from '@maka/runtime-host/protocol';
 import {
   DAILY_REVIEW_RANGES,
   normalizeDailyReviewConfig,
@@ -1422,6 +1423,20 @@ const makaBridge = {
     trace(sessionId: string): Promise<Result<SessionTrace>> {
       return bridgeResult(() => loadSessionTrace(sessionId), 'INSPECTOR_TRACE_FAILED');
     },
+    /**
+     * What the session's context is made of right now (#2323).
+     *
+     * A different question from "what happened in this session", and it has
+     * its own typed owner on the Host — the same snapshot `/context` prints.
+     * The Inspector asks that owner rather than widening the trace, so the two
+     * surfaces cannot drift into two implementations of one fact.
+     */
+    context(sessionId: string): Promise<Result<ContextDiagnosticsResult>> {
+      return bridgeResult(
+        () => runtimeHost.query('context.diagnostics.query', { sessionId }),
+        'INSPECTOR_CONTEXT_FAILED',
+      );
+    },
   },
   dailyReview: {
     day(offsetDays: number, daySpan?: number): Promise<Result<DailyReviewSummary>> {

apps/desktop/src/preload/runtime-host-renderer-operations.ts

@@ -1,6 +1,10 @@
 import type { OperationSpecMap } from '@maka/runtime-host/protocol';
 
 export const RENDERER_RUNTIME_HOST_QUERY_OPERATIONS = [
+  // Read-only, session-scoped, and already the owner of "what is the context
+  // made of" for `/context` (#1580, #2323). Admitted on the same terms as the
+  // inspect query beside it: it reads a projection and writes nothing.
+  'context.diagnostics.query',
   'daily-review.query',
   'execution.inspect.query',
   'scheduled-task.query',

apps/desktop/src/renderer/locales/conversation-copy.ts

@@ -216,6 +216,32 @@ export interface DesktopConversationCopy {
       cacheHit: string;
       /** Heading over the causal record. */
       timelineTab: string;
+      /**
+       * What filled the context, under the bar that says how full it is.
+       *
+       * Kept verbally separate from the bar on purpose: these are estimates
+       * over serialized bytes and do not sum to the provider-reported prompt
+       * (#2323), so the heading says estimate and every figure carries a `≈`.
+       */
+      composition: {
+        title: string;
+        /** States the unit and its authority, once, under the heading. */
+        basis: string;
+        part: {
+          system_instructions: string;
+          tool_definitions: string;
+          messages: string;
+          other: string;
+        };
+        /** Heading over the per-tool rows. */
+        tools: string;
+        /** The tools below the visible rows, folded into one. */
+        remainingTools: (count: number) => string;
+        /** Tool schemas the payload never named. */
+        unlabelled: string;
+        /** The metered call carried no capture — a gap, not an empty prompt. */
+        unrecorded: string;
+      };
     };
   };
   quoteCompanion: {
@@ -479,6 +505,20 @@ const COPY = {
         },
         cacheHit: '缓存命中率',
         timelineTab: '时间轴',
+        composition: {
+          title: '构成估算',
+          basis: '按请求字节估算，非模型报告的 token',
+          part: {
+            system_instructions: '系统提示',
+            tool_definitions: '工具定义',
+            messages: '对话记录',
+            other: '其他参数',
+          },
+          tools: '按工具',
+          remainingTools: (count) => `其余 ${count} 个工具`,
+          unlabelled: '未命名的工具',
+          unrecorded: '这次调用没有留下构成记录',
+        },
       },
     },
     quoteCompanion: {
@@ -666,6 +706,20 @@ const COPY = {
         },
         cacheHit: 'Cache hit rate',
         timelineTab: 'Timeline',
+        composition: {
+          title: 'Estimated composition',
+          basis: 'Estimated from request bytes, not provider-reported tokens',
+          part: {
+            system_instructions: 'System instructions',
+            tool_definitions: 'Tool definitions',
+            messages: 'Messages',
+            other: 'Other options',
+          },
+          tools: 'By tool',
+          remainingTools: (count) => `${count} more tool${count === 1 ? '' : 's'}`,
+          unlabelled: 'Unnamed tools',
+          unrecorded: 'This call left no composition on record',
+        },
       },
     },
     quoteCompanion: {