fix(ui): correct usage range totals and muted styles

src/infra/session-cost-usage.test.ts

@@ -371,4 +371,57 @@ describe("session cost usage", () => {
       }
     }
   });
+
+  it("preserves totals and cumulative values when downsampling timeseries", async () => {
+    const root = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-timeseries-downsample-"));
+    const sessionsDir = path.join(root, "agents", "main", "sessions");
+    await fs.mkdir(sessionsDir, { recursive: true });
+    const sessionFile = path.join(sessionsDir, "sess-downsample.jsonl");
+
+    const entries = Array.from({ length: 10 }, (_, i) => {
+      const idx = i + 1;
+      return {
+        type: "message",
+        timestamp: new Date(Date.UTC(2026, 1, 12, 10, idx, 0)).toISOString(),
+        message: {
+          role: "assistant",
+          provider: "openai",
+          model: "gpt-5.2",
+          usage: {
+            input: idx,
+            output: idx * 2,
+            cacheRead: 0,
+            cacheWrite: 0,
+            totalTokens: idx * 3,
+            cost: { total: idx * 0.001 },
+          },
+        },
+      };
+    });
+
+    await fs.writeFile(
+      sessionFile,
+      entries.map((entry) => JSON.stringify(entry)).join("\n"),
+      "utf-8",
+    );
+
+    const timeseries = await loadSessionUsageTimeSeries({
+      sessionFile,
+      maxPoints: 3,
+    });
+
+    expect(timeseries).toBeTruthy();
+    expect(timeseries?.points.length).toBe(3);
+
+    const points = timeseries?.points ?? [];
+    const totalTokens = points.reduce((sum, point) => sum + point.totalTokens, 0);
+    const totalCost = points.reduce((sum, point) => sum + point.cost, 0);
+    const lastPoint = points[points.length - 1];
+
+    // Full-series totals: sum(1..10)*3 = 165 tokens, sum(1..10)*0.001 = 0.055 cost.
+    expect(totalTokens).toBe(165);
+    expect(totalCost).toBeCloseTo(0.055, 8);
+    expect(lastPoint?.cumulativeTokens).toBe(165);
+    expect(lastPoint?.cumulativeCost).toBeCloseTo(0.055, 8);
+  });
 });

src/infra/session-cost-usage.ts

@@ -2,15 +2,8 @@ import fs from "node:fs";
 import path from "node:path";
 import readline from "node:readline";
 import type { NormalizedUsage, UsageLike } from "../agents/usage.js";
-import { normalizeUsage } from "../agents/usage.js";
 import type { OpenClawConfig } from "../config/config.js";
-import {
-  resolveSessionFilePath,
-  resolveSessionTranscriptsDirForAgent,
-} from "../config/sessions/paths.js";
 import type { SessionEntry } from "../config/sessions/types.js";
-import { countToolResults, extractToolCallNames } from "../utils/transcript-tools.js";
-import { estimateUsageCost, resolveModelCostConfig } from "../utils/usage-format.js";
 import type {
   CostBreakdown,
   CostUsageTotals,
@@ -31,6 +24,13 @@ import type {
   SessionUsageTimePoint,
   SessionUsageTimeSeries,
 } from "./session-cost-usage.types.js";
+import { normalizeUsage } from "../agents/usage.js";
+import {
+  resolveSessionFilePath,
+  resolveSessionTranscriptsDirForAgent,
+} from "../config/sessions/paths.js";
+import { countToolResults, extractToolCallNames } from "../utils/transcript-tools.js";
+import { estimateUsageCost, resolveModelCostConfig } from "../utils/usage-format.js";
 
 export type {
   CostUsageDailyEntry,
@@ -799,12 +799,44 @@ export async function loadSessionUsageTimeSeries(params: {
   if (sortedPoints.length > maxPoints) {
     const step = Math.ceil(sortedPoints.length / maxPoints);
     const downsampled: SessionUsageTimePoint[] = [];
+    let downsampledCumulativeTokens = 0;
+    let downsampledCumulativeCost = 0;
     for (let i = 0; i < sortedPoints.length; i += step) {
-      downsampled.push(sortedPoints[i]);
-    }
-    // Always include the last point
-    if (downsampled[downsampled.length - 1] !== sortedPoints[sortedPoints.length - 1]) {
-      downsampled.push(sortedPoints[sortedPoints.length - 1]);
+      const bucket = sortedPoints.slice(i, i + step);
+      const bucketLast = bucket[bucket.length - 1];
+      if (!bucketLast) {
+        continue;
+      }
+
+      let bucketInput = 0;
+      let bucketOutput = 0;
+      let bucketCacheRead = 0;
+      let bucketCacheWrite = 0;
+      let bucketTotalTokens = 0;
+      let bucketCost = 0;
+      for (const point of bucket) {
+        bucketInput += point.input;
+        bucketOutput += point.output;
+        bucketCacheRead += point.cacheRead;
+        bucketCacheWrite += point.cacheWrite;
+        bucketTotalTokens += point.totalTokens;
+        bucketCost += point.cost;
+      }
+
+      downsampledCumulativeTokens += bucketTotalTokens;
+      downsampledCumulativeCost += bucketCost;
+
+      downsampled.push({
+        timestamp: bucketLast.timestamp,
+        input: bucketInput,
+        output: bucketOutput,
+        cacheRead: bucketCacheRead,
+        cacheWrite: bucketCacheWrite,
+        totalTokens: bucketTotalTokens,
+        cost: bucketCost,
+        cumulativeTokens: downsampledCumulativeTokens,
+        cumulativeCost: downsampledCumulativeCost,
+      });
     }
     return { sessionId: params.sessionId, points: downsampled };
   }