feat(report): session outlier detection and per-model one-shot rates

src/analytics.ts

@@ -0,0 +1,120 @@
+import type { ProjectSummary, SessionSummary, TaskCategory } from './types.js'
+import { CATEGORY_LABELS } from './types.js'
+import { getShortModelName } from './models.js'
+
+export const TOP_OUTLIER_COUNT = 5
+export const OUTLIER_MULTIPLIER = 2
+
+export type OutlierSession = {
+  rank: number
+  project: string
+  sessionId: string
+  date: string
+  totalCostUSD: number
+  dominantActivity: string
+  isOutlier: boolean
+}
+
+export type ModelOneShotRow = {
+  model: string
+  sessions: number
+  oneShotTurns: number
+  editTurns: number
+  oneShotRate: number | null
+  costUSD: number
+}
+
+export function dominantActivity(session: SessionSummary): string {
+  let best: TaskCategory | null = null
+  let bestCost = 0
+  for (const [cat, data] of Object.entries(session.categoryBreakdown)) {
+    if (data.costUSD > bestCost) {
+      bestCost = data.costUSD
+      best = cat as TaskCategory
+    }
+  }
+  return best ? (CATEGORY_LABELS[best] ?? best) : 'General'
+}
+
+export function computeOutlierSessions(projects: ProjectSummary[]): OutlierSession[] {
+  const projectAvg = new Map<string, number>()
+  for (const p of projects) {
+    const avg = p.sessions.length > 0 ? p.totalCostUSD / p.sessions.length : 0
+    projectAvg.set(p.project, avg)
+  }
+
+  const all = projects.flatMap(p =>
+    p.sessions.map(s => ({ session: s, project: p.project }))
+  )
+  const sorted = [...all].sort((a, b) => b.session.totalCostUSD - a.session.totalCostUSD)
+  const top = sorted.slice(0, TOP_OUTLIER_COUNT)
+
+  return top.map(({ session, project }, i) => {
+    const avg = projectAvg.get(project) ?? 0
+    return {
+      rank: i + 1,
+      project,
+      sessionId: session.sessionId,
+      date: session.firstTimestamp ? session.firstTimestamp.slice(0, 10) : '----------',
+      totalCostUSD: session.totalCostUSD,
+      dominantActivity: dominantActivity(session),
+      isOutlier: avg > 0 && session.totalCostUSD > OUTLIER_MULTIPLIER * avg,
+    }
+  })
+}
+
+export function computeModelOneShotRates(projects: ProjectSummary[]): ModelOneShotRow[] {
+  const modelData = new Map<string, { oneShotTurns: number; editTurns: number; sessions: Set<string>; costUSD: number }>()
+
+  for (const project of projects) {
+    for (const session of project.sessions) {
+      for (const turn of session.turns) {
+        const primaryModel = turn.assistantCalls[0]
+          ? getShortModelName(turn.assistantCalls[0].model)
+          : null
+        if (!primaryModel) continue
+        const entry = modelData.get(primaryModel) ?? {
+          oneShotTurns: 0,
+          editTurns: 0,
+          sessions: new Set<string>(),
+          costUSD: 0,
+        }
+        if (turn.hasEdits) {
+          entry.editTurns++
+          if (turn.retries === 0) entry.oneShotTurns++
+        }
+        modelData.set(primaryModel, entry)
+      }
+      for (const [model, data] of Object.entries(session.modelBreakdown)) {
+        const entry = modelData.get(model) ?? {
+          oneShotTurns: 0,
+          editTurns: 0,
+          sessions: new Set<string>(),
+          costUSD: 0,
+        }
+        entry.costUSD += data.costUSD
+        entry.sessions.add(session.sessionId)
+        modelData.set(model, entry)
+      }
+    }
+  }
+
+  const rows: ModelOneShotRow[] = []
+  for (const [model, data] of modelData) {
+    rows.push({
+      model,
+      sessions: data.sessions.size,
+      oneShotTurns: data.oneShotTurns,
+      editTurns: data.editTurns,
+      oneShotRate: data.editTurns > 0 ? data.oneShotTurns / data.editTurns : null,
+      costUSD: data.costUSD,
+    })
+  }
+
+  return rows.sort((a, b) => {
+    if (a.oneShotRate === null && b.oneShotRate === null) return b.costUSD - a.costUSD
+    if (a.oneShotRate === null) return 1
+    if (b.oneShotRate === null) return -1
+    return b.oneShotRate - a.oneShotRate || b.costUSD - a.costUSD
+  })
+}

src/cli.ts

@@ -10,6 +10,7 @@ import { buildMenubarPayload } from './menubar-json.js'
 import { addNewDays, getDaysInRange, loadDailyCache, saveDailyCache, withDailyCacheLock } from './daily-cache.js'
 import { aggregateProjectsIntoDays, buildPeriodDataFromDays } from './day-aggregator.js'
 import { CATEGORY_LABELS, type DateRange, type ProjectSummary, type TaskCategory } from './types.js'
+import { computeOutlierSessions, computeModelOneShotRates } from './analytics.js'
 import { renderDashboard } from './dashboard.js'
 import { runOptimize, scanAndDetect } from './optimize.js'
 import { getAllProviders } from './providers/index.js'
@@ -204,6 +205,25 @@ function buildJsonReport(projects: ProjectSummary[], period: string, periodKey:
     .sort((a, b) => b.cost - a.cost)
     .slice(0, 5)
 
+  const outlierSessions = computeOutlierSessions(projects).map(r => ({
+    rank: r.rank,
+    project: r.project,
+    sessionId: r.sessionId,
+    date: r.date,
+    cost: convertCost(r.totalCostUSD),
+    dominantActivity: r.dominantActivity,
+    isOutlier: r.isOutlier,
+  }))
+
+  const modelOneShotRates = computeModelOneShotRates(projects).map(r => ({
+    model: r.model,
+    sessions: r.sessions,
+    oneShotRate: r.oneShotRate !== null ? Math.round(r.oneShotRate * 1000) / 10 : null,
+    editTurns: r.editTurns,
+    oneShotTurns: r.oneShotTurns,
+    cost: convertCost(r.costUSD),
+  }))
+
   return {
     generated: new Date().toISOString(),
     currency: code,
@@ -229,6 +249,8 @@ function buildJsonReport(projects: ProjectSummary[], period: string, periodKey:
     mcpServers: sortedMap(mcpMap),
     shellCommands: sortedMap(bashMap),
     topSessions,
+    outlierSessions,
+    modelOneShotRates,
   }
 }
 

src/dashboard.tsx

@@ -3,6 +3,7 @@ import { homedir } from 'os'
 import React, { useState, useCallback, useEffect, useRef } from 'react'
 import { render, Box, Text, useInput, useApp, useWindowSize } from 'ink'
 import { CATEGORY_LABELS, type ProjectSummary, type TaskCategory } from './types.js'
+import { computeOutlierSessions, computeModelOneShotRates, TOP_OUTLIER_COUNT, OUTLIER_MULTIPLIER } from './analytics.js'
 import { formatCost, formatTokens } from './format.js'
 import { parseAllSessions, filterProjectsByName } from './parser.js'
 import { loadPricing } from './models.js'
@@ -374,37 +375,73 @@ function ToolBreakdown({ projects, pw, bw, title, filterPrefix }: { projects: Pr
   )
 }
 
-const TOP_SESSIONS_DATE_LEN = 10
 const TOP_SESSIONS_COST_COL = 8
-const TOP_SESSIONS_CALLS_COL = 6
+const TOP_SESSIONS_ACT_COL = 13
+
+const MODEL_ONESHOT_NAME_WIDTH = 14
+const MODEL_ONESHOT_RATE_COL = 7
+const MODEL_ONESHOT_SESS_COL = 6
+const MODEL_ONESHOT_COST_COL = 8
+const MODEL_ONESHOT_HIGH_THRESHOLD = 0.9
+const MODEL_ONESHOT_MID_THRESHOLD = 0.7
 
 function TopSessions({ projects, pw, bw }: { projects: ProjectSummary[]; pw: number; bw: number }) {
-  const allSessions = projects.flatMap(p =>
-    p.sessions.map(s => ({ ...s, projectName: p.project }))
-  )
-  const top = [...allSessions].sort((a, b) => b.totalCostUSD - a.totalCostUSD).slice(0, 5)
+  const rows = computeOutlierSessions(projects)
 
-  if (top.length === 0) {
-    return <Panel title="Top Sessions" color={PANEL_COLORS.sessions} width={pw}><Text dimColor>No sessions</Text></Panel>
+  if (rows.length === 0) {
+    return <Panel title={`Top ${TOP_OUTLIER_COUNT} Sessions by Cost`} color={PANEL_COLORS.sessions} width={pw}><Text dimColor>No sessions</Text></Panel>
   }
 
-  const maxCost = top[0].totalCostUSD
-  const nw = Math.max(8, pw - bw - TOP_SESSIONS_COST_COL - TOP_SESSIONS_CALLS_COL - 1 - PANEL_CHROME)
+  const maxCost = rows[0].totalCostUSD
+  const nw = Math.max(8, pw - bw - TOP_SESSIONS_COST_COL - TOP_SESSIONS_ACT_COL - 2 - PANEL_CHROME)
 
   return (
-    <Panel title="Top Sessions" color={PANEL_COLORS.sessions} width={pw}>
-      <Text dimColor wrap="truncate-end">{''.padEnd(bw + 1 + nw)}{'cost'.padStart(TOP_SESSIONS_COST_COL)}{'calls'.padStart(TOP_SESSIONS_CALLS_COL)}</Text>
-      {top.map((session, i) => {
-        const date = session.firstTimestamp
-          ? session.firstTimestamp.slice(0, TOP_SESSIONS_DATE_LEN)
-          : '----------'
-        const label = `${date} ${shortProject(session.projectName)}`
+    <Panel title={`Top ${TOP_OUTLIER_COUNT} Sessions by Cost`} color={PANEL_COLORS.sessions} width={pw}>
+      <Text dimColor wrap="truncate-end">{''.padEnd(bw + 1 + nw)}{'cost'.padStart(TOP_SESSIONS_COST_COL)}{' activity'.padEnd(TOP_SESSIONS_ACT_COL + 1)}</Text>
+      {rows.map((row, i) => {
+        const label = `${row.date} ${shortProject(row.project)}`
         return (
-          <Text key={`${session.sessionId}-${i}`} wrap="truncate-end">
-            <HBar value={session.totalCostUSD} max={maxCost} width={bw} />
+          <Text key={`${row.sessionId}-${i}`} wrap="truncate-end">
+            <HBar value={row.totalCostUSD} max={maxCost} width={bw} />
             <Text dimColor> {fit(label, nw - 1)}</Text>
-            <Text color={GOLD}>{formatCost(session.totalCostUSD).padStart(TOP_SESSIONS_COST_COL)}</Text>
-            <Text>{String(session.apiCalls).padStart(TOP_SESSIONS_CALLS_COL)}</Text>
+            <Text color={row.isOutlier ? '#F55B5B' : GOLD}>{formatCost(row.totalCostUSD).padStart(TOP_SESSIONS_COST_COL)}</Text>
+            <Text dimColor> {fit(row.dominantActivity, TOP_SESSIONS_ACT_COL)}</Text>
+          </Text>
+        )
+      })}
+      <Text dimColor wrap="truncate-end">red cost = outlier ({'>'}{OUTLIER_MULTIPLIER}x project avg)</Text>
+    </Panel>
+  )
+}
+
+function ModelOneShotBreakdown({ projects, pw, bw }: { projects: ProjectSummary[]; pw: number; bw: number }) {
+  const rows = computeModelOneShotRates(projects)
+
+  if (rows.length === 0) {
+    return <Panel title="One-Shot Rate by Model" color={PANEL_COLORS.model} width={pw}><Text dimColor>No model data</Text></Panel>
+  }
+
+  const maxCost = Math.max(...rows.map(r => r.costUSD))
+
+  return (
+    <Panel title="One-Shot Rate by Model" color={PANEL_COLORS.model} width={pw}>
+      <Text dimColor wrap="truncate-end">{''.padEnd(bw + 1 + MODEL_ONESHOT_NAME_WIDTH)}{'cost'.padStart(MODEL_ONESHOT_COST_COL)}{'sess'.padStart(MODEL_ONESHOT_SESS_COL)}{'1-shot'.padStart(MODEL_ONESHOT_RATE_COL)}</Text>
+      {rows.map((row, i) => {
+        const rateLabel = row.oneShotRate !== null ? `${Math.round(row.oneShotRate * 100)}%` : '-'
+        const rateColor = row.oneShotRate === null
+          ? DIM
+          : row.oneShotRate >= MODEL_ONESHOT_HIGH_THRESHOLD
+            ? '#5BF58C'
+            : row.oneShotRate >= MODEL_ONESHOT_MID_THRESHOLD
+              ? ORANGE
+              : '#F55B5B'
+        return (
+          <Text key={`${row.model}-${i}`} wrap="truncate-end">
+            <HBar value={row.costUSD} max={maxCost} width={bw} />
+            <Text> {fit(row.model, MODEL_ONESHOT_NAME_WIDTH)}</Text>
+            <Text color={GOLD}>{formatCost(row.costUSD).padStart(MODEL_ONESHOT_COST_COL)}</Text>
+            <Text>{String(row.sessions).padStart(MODEL_ONESHOT_SESS_COL)}</Text>
+            <Text color={rateColor}>{rateLabel.padStart(MODEL_ONESHOT_RATE_COL)}</Text>
           </Text>
         )
       })}
@@ -565,6 +602,7 @@ function DashboardContent({ projects, period, columns, activeProvider, budgets }
       <Row wide={wide} width={dashWidth}><DailyActivity projects={projects} days={days} pw={pw} bw={barWidth} /><ProjectBreakdown projects={projects} pw={pw} bw={barWidth} budgets={budgets} /></Row>
       <TopSessions projects={projects} pw={dashWidth} bw={barWidth} />
       <Row wide={wide} width={dashWidth}><ActivityBreakdown projects={projects} pw={pw} bw={barWidth} /><ModelBreakdown projects={projects} pw={pw} bw={barWidth} /></Row>
+      <ModelOneShotBreakdown projects={projects} pw={dashWidth} bw={barWidth} />
       {isCursor ? (
         <ToolBreakdown projects={projects} pw={dashWidth} bw={barWidth} title="Languages" filterPrefix="lang:" />
       ) : (