Fix cumulative platform cost Stripe double-counting

Split infrastructure vs payment-processing costs. Liquidity burn now uses infrastructure cash out only (€1,155.20 cumulative) because Stripe fees are already deducted from net member payments. Total platform cost (€1,158.24) remains visible for gross-margin economics.
2026-06-22 01:51:53 +02:00
parent fe2174f37a
commit ea2c2c6403
8 changed files with 143 additions and 97 deletions
--- a/projects/coulomb-pricing/observatory/dashboard.py
+++ b/projects/coulomb-pricing/observatory/dashboard.py
@@ -30,10 +30,11 @@ def _history_rows(
            continue
        payment = revenue_by_period.get(month.period)
        net_payment = payment.net_amount if payment else Decimal("0")
-        period_net = net_payment - month.platform_cost
+        period_net = net_payment - month.infrastructure_cost
        lines.append(
            f"| {month.period} | {month.active_members} | {month.gross_revenue} | "
-            f"{month.platform_cost} | {period_net:.2f} |"
+            f"{month.infrastructure_cost} | {month.payment_processing_cost} | "
+            f"{month.total_platform_cost} | {period_net:.2f} |"
        )
    return "\n".join(lines)

@@ -73,12 +74,15 @@ def render_dashboard(
 |--------|------:|
 | Active members | {snapshot.active_members} |
 | Member payments (gross) | {snapshot.monthly_revenue} {snapshot.currency} |
-| Platform cost | {snapshot.monthly_platform_cost} {snapshot.currency} |
+| Infrastructure cost | {snapshot.monthly_infrastructure_cost} {snapshot.currency} |
+| Payment processing cost | {snapshot.monthly_payment_processing_cost} {snapshot.currency} |
+| Total platform cost | {snapshot.monthly_total_platform_cost} {snapshot.currency} |
 | Platform cost per member | {snapshot.cost_per_member} {snapshot.currency} |
 | Period gross margin | {snapshot.gross_margin} {snapshot.currency} |
 | Period gross margin % | {snapshot.gross_margin_pct}% |
 | Period net liquidity | {snapshot.period_net_liquidity} {snapshot.currency} ({snapshot.liquidity_status}) |

+_Period net liquidity = net member payments − infrastructure cost (processing fees already netted from payments)._  
 _Revenue source: {snapshot.revenue_source}_

 ## Liquidity & Budget (through {liquidity.through_period})
@@ -87,15 +91,17 @@ _Revenue source: {snapshot.revenue_source}_
 |--------|------:|
 | Initial budget | {liquidity.initial_budget} {liquidity.currency} |
 | Cumulative member payments (net) | {liquidity.cumulative_member_payments} {liquidity.currency} |
-| Cumulative platform cost | {liquidity.cumulative_platform_cost} {liquidity.currency} |
+| Cumulative infrastructure cost | {liquidity.cumulative_infrastructure_cost} {liquidity.currency} |
+| Cumulative payment processing | {liquidity.cumulative_payment_processing_cost} {liquidity.currency} |
+| Cumulative total platform cost | {liquidity.cumulative_total_platform_cost} {liquidity.currency} |
 | Cumulative net liquidity | {liquidity.cumulative_net_liquidity} {liquidity.currency} ({liquidity.liquidity_status}) |
 | Remaining budget | {liquidity.remaining_budget} {liquidity.currency} ({budget_state}) |
 | Months tracked | {liquidity.months_tracked} |

 ## Monthly History

-| Period | Members | Gross revenue | Platform cost | Net liquidity |
-|--------|--------:|--------------:|--------------:|--------------:|
+| Period | Members | Gross revenue | Infrastructure | Processing | Total platform | Net liquidity |
+|--------|--------:|--------------:|---------------:|-----------:|---------------:|--------------:|
 {history_lines}

 ## Pricing Model Registry
--- a/projects/coulomb-pricing/observatory/economics.py
+++ b/projects/coulomb-pricing/observatory/economics.py
@@ -112,22 +112,29 @@ def build_liquidity_summary(
    cost_by_period = {item.period: item for item in monthly_costs}

    cumulative_payments = Decimal("0")
-    cumulative_cost = Decimal("0")
+    cumulative_infrastructure = Decimal("0")
+    cumulative_processing = Decimal("0")
    for period in tracked:
        month = cost_by_period[period]
-        cumulative_cost += month.platform_cost
+        cumulative_infrastructure += month.infrastructure_cost
+        cumulative_processing += month.payment_processing_cost
        payment = revenue_for_period(period, revenue_entries)
        cumulative_payments += payment.net_amount if payment else Decimal("0")

-    cumulative_net = _quantize(cumulative_payments - cumulative_cost)
+    # Liquidity uses net member payments vs infrastructure cash out only.
+    # Payment-processing fees are already deducted from net payments.
+    cumulative_net = _quantize(cumulative_payments - cumulative_infrastructure)
    remaining = _quantize(budget.initial_budget + cumulative_net)
+    cumulative_total = _quantize(cumulative_infrastructure + cumulative_processing)

    return LiquiditySummary(
        currency=budget.currency,
        through_period=through_period,
        initial_budget=budget.initial_budget,
        cumulative_member_payments=_quantize(cumulative_payments),
-        cumulative_platform_cost=_quantize(cumulative_cost),
+        cumulative_infrastructure_cost=_quantize(cumulative_infrastructure),
+        cumulative_payment_processing_cost=_quantize(cumulative_processing),
+        cumulative_total_platform_cost=cumulative_total,
        cumulative_net_liquidity=cumulative_net,
        remaining_budget=remaining,
        liquidity_status=liquidity_status_for(cumulative_net),
@@ -148,22 +155,26 @@ def build_snapshot(
    gross_revenue, net_revenue, revenue_source = estimate_monthly_revenue(
        period, product, models, members, revenue_entries, monthly_costs
    )
-    platform_cost = month.platform_cost
-    cost_per_member = _quantize(platform_cost / count) if count else Decimal("0.00")
-    gross_margin = _quantize(gross_revenue - platform_cost)
+    infrastructure = month.infrastructure_cost
+    processing = month.payment_processing_cost
+    total_platform = month.total_platform_cost
+    cost_per_member = _quantize(total_platform / count) if count else Decimal("0.00")
+    gross_margin = _quantize(gross_revenue - total_platform)
    margin_pct = (
        _quantize((gross_margin / gross_revenue) * Decimal("100"), PCTPLACES)
        if gross_revenue
-        else Decimal("-100.0") if platform_cost else Decimal("0.0")
+        else Decimal("-100.0") if total_platform else Decimal("0.0")
    )
-    period_net = _quantize(net_revenue - platform_cost)
+    period_net = _quantize(net_revenue - infrastructure)

    return EconomicsSnapshot(
        period=period,
        currency=product.currency,
        active_members=count,
        monthly_revenue=_quantize(gross_revenue),
-        monthly_platform_cost=platform_cost,
+        monthly_infrastructure_cost=infrastructure,
+        monthly_payment_processing_cost=processing,
+        monthly_total_platform_cost=total_platform,
        cost_per_member=cost_per_member,
        gross_margin=gross_margin,
        gross_margin_pct=margin_pct,
--- a/projects/coulomb-pricing/observatory/load.py
+++ b/projects/coulomb-pricing/observatory/load.py
@@ -4,6 +4,8 @@ import json
 from decimal import Decimal
 from pathlib import Path

+_ZERO = Decimal("0")
+
 from .models import (
    Budget,
    CostEntry,
@@ -89,15 +91,25 @@ def load_cost_rate_card(data_dir: Path | None = None) -> tuple[list[CostEntry],

 def load_monthly_platform_costs(data_dir: Path | None = None) -> list[MonthlyPlatformCost]:
    raw = _read_json((data_dir or default_data_dir()) / "costs.json")
-    return [
-        MonthlyPlatformCost(
-            period=item["period"],
-            platform_cost=_money(item["platform_cost"]),
-            active_members=item["active_members"],
-            gross_revenue=_money(item["gross_revenue"]),
+    rows: list[MonthlyPlatformCost] = []
+    for item in raw.get("monthly_history", []):
+        if "infrastructure_cost" in item:
+            infrastructure = _money(item["infrastructure_cost"])
+            processing = _money(item.get("payment_processing_cost", "0"))
+        else:
+            # Legacy single platform_cost field treated as infrastructure only.
+            infrastructure = _money(item["platform_cost"])
+            processing = _ZERO
+        rows.append(
+            MonthlyPlatformCost(
+                period=item["period"],
+                infrastructure_cost=infrastructure,
+                payment_processing_cost=processing,
+                active_members=item["active_members"],
+                gross_revenue=_money(item["gross_revenue"]),
+            )
        )
-        for item in raw.get("monthly_history", [])
-    ]
+    return rows


 def load_revenue(data_dir: Path | None = None) -> list[RevenueEntry]:
--- a/projects/coulomb-pricing/observatory/models.py
+++ b/projects/coulomb-pricing/observatory/models.py
@@ -46,10 +46,15 @@ class CostEntry:
@dataclass(frozen=True)
 class MonthlyPlatformCost:
    period: str
-    platform_cost: Decimal
+    infrastructure_cost: Decimal
+    payment_processing_cost: Decimal
    active_members: int
    gross_revenue: Decimal

+    @property
+    def total_platform_cost(self) -> Decimal:
+        return self.infrastructure_cost + self.payment_processing_cost
+

@dataclass(frozen=True)
 class Budget:
@@ -85,7 +90,9 @@ class EconomicsSnapshot:
    currency: str
    active_members: int
    monthly_revenue: Decimal
-    monthly_platform_cost: Decimal
+    monthly_infrastructure_cost: Decimal
+    monthly_payment_processing_cost: Decimal
+    monthly_total_platform_cost: Decimal
    cost_per_member: Decimal
    gross_margin: Decimal
    gross_margin_pct: Decimal
@@ -101,7 +108,9 @@ class LiquiditySummary:
    through_period: str
    initial_budget: Decimal
    cumulative_member_payments: Decimal
-    cumulative_platform_cost: Decimal
+    cumulative_infrastructure_cost: Decimal
+    cumulative_payment_processing_cost: Decimal
+    cumulative_total_platform_cost: Decimal
    cumulative_net_liquidity: Decimal
    remaining_budget: Decimal
    liquidity_status: LiquidityStatus