feat: add FinOps model choice opportunity scoring

ROADMAP.md

@@ -215,7 +215,7 @@ As usage grows, the platform needs stronger derived data pipelines, performance
 - [ ] [P1] Break-even analysis for API vs seat-based pricing with per-engineer recommendations
 - [x] [P1] Cost per workflow archetype and cost per engineering outcome
 - [x] [P1] Workflow compare mode for archetype and fingerprint performance
-- [ ] [P1] Model-choice opportunity scoring for overspend reduction
+- [x] [P1] Model-choice opportunity scoring for overspend reduction
 - [ ] [P2] Budget policy simulation by team, project, and billing model
 
 ## AI Synthesis & Explorer

frontend/src/components/finops/__tests__/model-choice-opportunity-table.test.tsx

@@ -0,0 +1,46 @@
+import { render, screen } from "@testing-library/react"
+
+import { ModelChoiceOpportunityTable } from "@/components/finops/model-choice-opportunity-table"
+
+describe("ModelChoiceOpportunityTable", () => {
+  it("renders an empty state when no opportunities exist", () => {
+    render(<ModelChoiceOpportunityTable opportunities={[]} totalSavingsMonthly={0} />)
+
+    expect(
+      screen.getByText("No clear model downshift opportunities found for this period yet."),
+    ).toBeInTheDocument()
+  })
+
+  it("renders scored opportunities", () => {
+    render(
+      <ModelChoiceOpportunityTable
+        totalSavingsMonthly={14.2}
+        opportunities={[
+          {
+            workflow_archetype: "debugging",
+            current_model: "claude-opus-4-20250514",
+            recommended_model: "claude-sonnet-4-5-20250929",
+            current_session_count: 8,
+            supporting_session_count: 12,
+            current_success_rate: 0.82,
+            recommended_success_rate: 0.84,
+            current_avg_cost: 4.8,
+            recommended_avg_cost: 1.1,
+            period_savings_estimate: 22.4,
+            monthly_savings_estimate: 14.2,
+            confidence: "high",
+            rationale: "Peers get similar results with Sonnet for debugging work.",
+          },
+        ]}
+      />,
+    )
+
+    expect(screen.getByText("Model choice opportunities")).toBeInTheDocument()
+    expect(
+      screen.getByText("claude-opus-4-20250514 -> claude-sonnet-4-5-20250929"),
+    ).toBeInTheDocument()
+    expect(screen.getByText("Debugging")).toBeInTheDocument()
+    expect(screen.getByText("High confidence")).toBeInTheDocument()
+    expect(screen.getAllByText("$14.20")).toHaveLength(2)
+  })
+})

frontend/src/components/finops/model-choice-opportunity-table.tsx

@@ -0,0 +1,125 @@
+import { Badge } from "@/components/ui/badge"
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card"
+import { formatCost, formatLabel, formatPercent } from "@/lib/utils"
+import type { ModelChoiceOpportunity } from "@/types/api"
+
+interface ModelChoiceOpportunityTableProps {
+  opportunities: ModelChoiceOpportunity[]
+  totalSavingsMonthly: number
+}
+
+const confidenceVariant: Record<string, "default" | "secondary" | "outline"> = {
+  high: "default",
+  medium: "secondary",
+  low: "outline",
+}
+
+export function ModelChoiceOpportunityTable({
+  opportunities,
+  totalSavingsMonthly,
+}: ModelChoiceOpportunityTableProps) {
+  return (
+    <Card>
+      <CardHeader className="pb-3">
+        <div className="flex flex-wrap items-start justify-between gap-3">
+          <div>
+            <CardTitle className="text-sm font-medium">Model choice opportunities</CardTitle>
+            <p className="mt-1 text-sm text-muted-foreground">
+              Places where a cheaper model appears to preserve outcomes for the same workflow.
+            </p>
+          </div>
+          <div className="rounded-xl border border-border/70 bg-muted/40 px-3 py-2 text-right">
+            <p className="text-[11px] font-semibold uppercase tracking-[0.18em] text-muted-foreground">
+              Potential Monthly Savings
+            </p>
+            <p className="mt-1 font-display text-2xl tracking-tight">
+              {formatCost(totalSavingsMonthly)}
+            </p>
+          </div>
+        </div>
+      </CardHeader>
+      <CardContent>
+        {opportunities.length === 0 ? (
+          <p className="text-sm text-muted-foreground">
+            No clear model downshift opportunities found for this period yet.
+          </p>
+        ) : (
+          <div className="space-y-3">
+            {opportunities.map((opportunity) => (
+              <div
+                key={`${opportunity.workflow_archetype}:${opportunity.current_model}:${opportunity.recommended_model}`}
+                className="rounded-2xl border border-border/70 bg-card/70 p-4"
+              >
+                <div className="flex flex-wrap items-start justify-between gap-3">
+                  <div className="space-y-1">
+                    <div className="flex flex-wrap items-center gap-2">
+                      <Badge variant="outline">
+                        {formatLabel(opportunity.workflow_archetype)}
+                      </Badge>
+                      <Badge
+                        variant={confidenceVariant[opportunity.confidence] ?? "outline"}
+                      >
+                        {formatLabel(opportunity.confidence)} confidence
+                      </Badge>
+                    </div>
+                    <p className="text-base font-semibold">
+                      {opportunity.current_model} {"->"} {opportunity.recommended_model}
+                    </p>
+                    <p className="text-sm text-muted-foreground">{opportunity.rationale}</p>
+                  </div>
+                  <div className="text-right">
+                    <p className="text-[11px] font-semibold uppercase tracking-[0.18em] text-muted-foreground">
+                      Monthly Savings
+                    </p>
+                    <p className="mt-1 text-xl font-semibold">
+                      {formatCost(opportunity.monthly_savings_estimate)}
+                    </p>
+                  </div>
+                </div>
+
+                <div className="mt-4 grid gap-3 sm:grid-cols-4">
+                  <div>
+                    <p className="text-xs uppercase tracking-wide text-muted-foreground">
+                      Success
+                    </p>
+                    <p className="mt-1 text-sm">
+                      {formatPercent(opportunity.current_success_rate)}
+                      {" -> "}
+                      {formatPercent(opportunity.recommended_success_rate)}
+                    </p>
+                  </div>
+                  <div>
+                    <p className="text-xs uppercase tracking-wide text-muted-foreground">
+                      Avg Cost
+                    </p>
+                    <p className="mt-1 text-sm">
+                      {opportunity.current_avg_cost != null
+                        ? formatCost(opportunity.current_avg_cost)
+                        : "-"}
+                      {" -> "}
+                      {opportunity.recommended_avg_cost != null
+                        ? formatCost(opportunity.recommended_avg_cost)
+                        : "-"}
+                    </p>
+                  </div>
+                  <div>
+                    <p className="text-xs uppercase tracking-wide text-muted-foreground">
+                      Current Sessions
+                    </p>
+                    <p className="mt-1 text-sm">{opportunity.current_session_count}</p>
+                  </div>
+                  <div>
+                    <p className="text-xs uppercase tracking-wide text-muted-foreground">
+                      Benchmark Sessions
+                    </p>
+                    <p className="mt-1 text-sm">{opportunity.supporting_session_count}</p>
+                  </div>
+                </div>
+              </div>
+            ))}
+          </div>
+        )}
+      </CardContent>
+    </Card>
+  )
+}

frontend/src/components/finops/modeling-tab.tsx

@@ -15,6 +15,7 @@ import { ChartTooltip } from "@/components/charts/chart-tooltip"
 import { CHART_COLORS, AXIS_TICK_STYLE } from "@/lib/chart-colors"
 import { useCostModeling } from "@/hooks/use-api-queries"
 import { CardSkeleton, ChartSkeleton, TableSkeleton } from "@/components/shared/loading-skeleton"
+import { ModelChoiceOpportunityTable } from "@/components/finops/model-choice-opportunity-table"
 import { formatCost, cn } from "@/lib/utils"
 
 const TIER_COLORS: Record<string, string> = {
@@ -136,6 +137,11 @@ export function ModelingTab({ teamId, startDate, endDate }: ModelingTabProps) {
         </div>
       )}
 
+      <ModelChoiceOpportunityTable
+        opportunities={data.model_choice_opportunities}
+        totalSavingsMonthly={data.total_model_choice_savings_monthly}
+      />
+
       {/* Efficient Frontier Chart */}
       {chartData.length > 0 && (
         <Card>

frontend/src/types/api.ts

@@ -1908,6 +1908,22 @@ export interface PlanAllocationSummary {
   total_monthly_cost: number
 }
 
+export interface ModelChoiceOpportunity {
+  workflow_archetype: string
+  current_model: string
+  recommended_model: string
+  current_session_count: number
+  supporting_session_count: number
+  current_success_rate: number | null
+  recommended_success_rate: number | null
+  current_avg_cost: number | null
+  recommended_avg_cost: number | null
+  period_savings_estimate: number
+  monthly_savings_estimate: number
+  confidence: string
+  rationale: string
+}
+
 export interface CostModelingResponse {
   period_days: number
   plan_tiers: PlanTier[]
@@ -1916,6 +1932,8 @@ export interface CostModelingResponse {
   total_api_cost_monthly: number
   total_optimal_cost_monthly: number
   total_savings_monthly: number
+  model_choice_opportunities: ModelChoiceOpportunity[]
+  total_model_choice_savings_monthly: number
 }
 
 export interface ForecastPoint {

src/primer/common/schemas.py

@@ -2303,6 +2303,22 @@ class PlanAllocationSummary(BaseModel):
     total_monthly_cost: float
 
 
+class ModelChoiceOpportunity(BaseModel):
+    workflow_archetype: str
+    current_model: str
+    recommended_model: str
+    current_session_count: int
+    supporting_session_count: int
+    current_success_rate: float | None = None
+    recommended_success_rate: float | None = None
+    current_avg_cost: float | None = None
+    recommended_avg_cost: float | None = None
+    period_savings_estimate: float
+    monthly_savings_estimate: float
+    confidence: str
+    rationale: str
+
+
 class CostModelingResponse(BaseModel):
     period_days: int
     plan_tiers: list[PlanTier]
@@ -2311,6 +2327,8 @@ class CostModelingResponse(BaseModel):
     total_api_cost_monthly: float
     total_optimal_cost_monthly: float
     total_savings_monthly: float
+    model_choice_opportunities: list[ModelChoiceOpportunity] = []
+    total_model_choice_savings_monthly: float = 0.0
 
 
 # --- FinOps: Forecasting ---