Refactor economics to expense-record ledger with correct Bubble cost

Replace pre-aggregated costs.json with expense_records.json (48 line-item records) and payment_records.json. All monthly and cumulative totals are computed deterministically in observatory/ledger.py. Correct Bubble.io to $32/mo (since Feb 2025) — infrastructure €69.44/mo not €72.20.
2026-06-22 02:03:22 +02:00
parent ea2c2c6403
commit 31db9f8f31
12 changed files with 843 additions and 299 deletions
--- a/projects/coulomb-pricing/README.md
+++ b/projects/coulomb-pricing/README.md
@@ -10,21 +10,21 @@ Liquidity and cost requirements: `REQUIREMENTS.md`.

 ## Sprint 1 — Economic Foundations

-The `observatory/` package loads JSON registries and produces **Economics
-Dashboard v1** with platform-cost history, member payments, and budget burn.
+The `observatory/` package reads **expense and payment record ledgers** and
+computes all totals programmatically (`ledger.py` → `economics.py`).

-| Registry | File |
-|----------|------|
+| Ledger | File |
+|--------|------|
 | Budget (€1,000 start) | `data/budget.json` |
+| Expense records | `data/expense_records.json` |
+| Payment records | `data/payment_records.json` |
 | Product model | `data/product.json` |
 | Pricing models | `data/pricing-models.json` |
-| Platform costs + history | `data/costs.json` |
-| Member payments | `data/revenue.json` |
 | Membership | `data/membership.json` |

-**Current reality:** platform costs from March 2025; sole member payments from
-November 2025. Operator is **burning liquidity** — platform spend exceeds
-subscription intake. Customer cost-pass-through billing is not active.
+**Current reality:** platform costs from March 2025 (Bubble.io **$32/mo** since
+Feb 2025); sole member payments from November 2025. Operator is **burning
+liquidity**. Customer cost-pass-through billing is not active.

 ### Commands

@@ -35,5 +35,5 @@ python3 -m observatory --period 2026-06
 python3 -m observatory --period 2026-06 --output reports/economics-2026-06.md
 ```

-Manual registries will be replaced by Bubble (Sprint 2), Stripe (Sprint 3), and
+Manual ledgers will be replaced by Bubble (Sprint 2), Stripe (Sprint 3), and
 OpenRouter (Sprint 4) importers.
--- a/projects/coulomb-pricing/REQUIREMENTS.md
+++ b/projects/coulomb-pricing/REQUIREMENTS.md
@@ -11,15 +11,20 @@ The Economic Observatory must make the resulting **liquidity burn** visible.

 ## Requirements

-### LQ-001 — Platform cost ledger
+### LQ-001 — Expense record ledger (source of truth)

-Record monthly platform costs from project start (March 2025), including fixed
-infrastructure and payment-provider variable fees when member revenue exists.
+Capture every operator expense as an individual record in
+`data/expense_records.json`. Fields: `period`, `vendor`, `amount`, `currency`,
+`cost_class`, `source`.

-### LQ-002 — Member payment ledger
+**Never store hand-calculated monthly or cumulative totals in data files.**
+All aggregations must be computed programmatically by `observatory/ledger.py`.

-Record member subscription payments from first payment month (November 2025),
-separate from platform cost accrual.
+### LQ-002 — Payment record ledger
+
+Capture member subscription payments in `data/payment_records.json` with gross,
+fees, and net amounts per period. Payment-processing totals are summed from
+`fees_amount` — not duplicated as expense records.

 ### LQ-003 — Budget tracking

@@ -36,18 +41,15 @@ liquidity each period:
 - `cumulative_net = sum(period_net)`
 - `remaining_budget = initial_budget + cumulative_net`

-**No double-counting:** payment-processing fees (Stripe) are deducted from net
-member payments. They are tracked separately for economics reporting but must
-**not** be subtracted again in the liquidity formula.
+**No double-counting:** payment-processing fees are deducted from net member
+payments. They are summed separately for economics reporting but must **not** be
+subtracted again in the liquidity formula.

 - `total_platform_cost = infrastructure_cost + payment_processing_cost` (for
  gross-margin economics vs gross revenue)
 - `cumulative_total_platform_cost` is informational; liquidity burn uses
  `cumulative_infrastructure_cost` only

-Negative remaining budget means the MVP has consumed more liquidity than the
-allocated budget.
-
 ### LQ-005 — No customer cost billing (MVP boundary)

 Do not allocate platform costs to customer invoices in MVP. Cost attribution
@@ -60,16 +62,22 @@ Economics Dashboard must show:

 - Current-period economics (revenue, platform cost, margin)
 - Cumulative liquidity summary (budget, burn, remaining)
- Monthly history table from March 2025
+- Monthly history table computed from ledgers
+
+### LQ-007 — Deterministic calculation engine
+
+All economics and liquidity figures must be produced by the Python observatory
+package (`ledger.py`, `economics.py`). LLM or manual arithmetic must not be the
+source of aggregated totals.

 ## Data sources (current)

-| Registry | Path |
-|----------|------|
+| Ledger | Path |
+|--------|------|
 | Budget | `data/budget.json` |
-| Platform costs | `data/costs.json` (`rate_card` + `monthly_history`) |
-| Member payments | `data/revenue.json` |
+| Expense records | `data/expense_records.json` |
+| Payment records | `data/payment_records.json` |
 | Membership | `data/membership.json` |

-Future sprints replace manual history with Bubble, Stripe, and OpenRouter imports
-while preserving the same liquidity semantics.
+Future sprints replace manual records with Bubble, Stripe, and OpenRouter imports
+while preserving the same ledger schema and calculation rules.
--- a/projects/coulomb-pricing/data/costs.json
+++ b/projects/coulomb-pricing/data/costs.json
@@ -1,72 +0,0 @@
-{
-  "version": 2,
-  "fx_rates": {
-    "USD/EUR": "0.92"
-  },
-  "rate_card": [
-    {
-      "id": "bubble-subscription",
-      "name": "Bubble.io platform",
-      "category": "fixed",
-      "amount": "35.00",
-      "currency": "USD",
-      "cadence": "monthly",
-      "allocation": "flat"
-    },
-    {
-      "id": "domains",
-      "name": "Domains",
-      "category": "fixed",
-      "amount": "15.00",
-      "currency": "EUR",
-      "cadence": "monthly",
-      "allocation": "flat"
-    },
-    {
-      "id": "operational-overhead",
-      "name": "Operational overhead",
-      "category": "fixed",
-      "amount": "25.00",
-      "currency": "EUR",
-      "cadence": "monthly",
-      "allocation": "flat"
-    },
-    {
-      "id": "stripe-percentage",
-      "name": "Stripe percentage fee",
-      "category": "variable",
-      "amount": "0.015",
-      "currency": "ratio",
-      "cadence": "per_transaction",
-      "allocation": "percent_of_gross_revenue"
-    },
-    {
-      "id": "stripe-fixed",
-      "name": "Stripe fixed fee",
-      "category": "variable",
-      "amount": "0.25",
-      "currency": "EUR",
-      "cadence": "per_transaction",
-      "allocation": "per_active_member"
-    }
-  ],
-  "monthly_history": [
-    {"period": "2025-03", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-04", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-05", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-06", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-07", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-08", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-09", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-10", "infrastructure_cost": "72.20", "payment_processing_cost": "0.00", "active_members": 0, "gross_revenue": "0.00"},
-    {"period": "2025-11", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"},
-    {"period": "2025-12", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"},
-    {"period": "2026-01", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"},
-    {"period": "2026-02", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"},
-    {"period": "2026-03", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"},
-    {"period": "2026-04", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"},
-    {"period": "2026-05", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"},
-    {"period": "2026-06", "infrastructure_cost": "72.20", "payment_processing_cost": "0.38", "active_members": 1, "gross_revenue": "8.99"}
-  ],
-  "note": "Infrastructure costs are operator cash outflows. Payment processing is tracked separately and already deducted from net member payments — do not double-count in liquidity."
-}
--- a/projects/coulomb-pricing/data/expense_records.json
+++ b/projects/coulomb-pricing/data/expense_records.json
@@ -0,0 +1,489 @@
+{
+  "version": 1,
+  "fx_rates": {
+    "USD/EUR": "0.92"
+  },
+  "records": [
+    {
+      "id": "exp-bubble-2025-03",
+      "period": "2025-03",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-03",
+      "period": "2025-03",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-03",
+      "period": "2025-03",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-04",
+      "period": "2025-04",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-04",
+      "period": "2025-04",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-04",
+      "period": "2025-04",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-05",
+      "period": "2025-05",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-05",
+      "period": "2025-05",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-05",
+      "period": "2025-05",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-06",
+      "period": "2025-06",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-06",
+      "period": "2025-06",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-06",
+      "period": "2025-06",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-07",
+      "period": "2025-07",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-07",
+      "period": "2025-07",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-07",
+      "period": "2025-07",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-08",
+      "period": "2025-08",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-08",
+      "period": "2025-08",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-08",
+      "period": "2025-08",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-09",
+      "period": "2025-09",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-09",
+      "period": "2025-09",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-09",
+      "period": "2025-09",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-10",
+      "period": "2025-10",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-10",
+      "period": "2025-10",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-10",
+      "period": "2025-10",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-11",
+      "period": "2025-11",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-11",
+      "period": "2025-11",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-11",
+      "period": "2025-11",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2025-12",
+      "period": "2025-12",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2025-12",
+      "period": "2025-12",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2025-12",
+      "period": "2025-12",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2026-01",
+      "period": "2026-01",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2026-01",
+      "period": "2026-01",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2026-01",
+      "period": "2026-01",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2026-02",
+      "period": "2026-02",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2026-02",
+      "period": "2026-02",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2026-02",
+      "period": "2026-02",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2026-03",
+      "period": "2026-03",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2026-03",
+      "period": "2026-03",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2026-03",
+      "period": "2026-03",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2026-04",
+      "period": "2026-04",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2026-04",
+      "period": "2026-04",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2026-04",
+      "period": "2026-04",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2026-05",
+      "period": "2026-05",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2026-05",
+      "period": "2026-05",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2026-05",
+      "period": "2026-05",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-bubble-2026-06",
+      "period": "2026-06",
+      "vendor": "bubble.io",
+      "description": "Bubble.io Personal plan ($32/mo since Feb 2025)",
+      "cost_class": "infrastructure",
+      "amount": "32.00",
+      "currency": "USD",
+      "source": "manual"
+    },
+    {
+      "id": "exp-domains-2026-06",
+      "period": "2026-06",
+      "vendor": "domains",
+      "description": "Domain registrations",
+      "cost_class": "infrastructure",
+      "amount": "15.00",
+      "currency": "EUR",
+      "source": "manual"
+    },
+    {
+      "id": "exp-overhead-2026-06",
+      "period": "2026-06",
+      "vendor": "operational-overhead",
+      "description": "Operational overhead",
+      "cost_class": "infrastructure",
+      "amount": "25.00",
+      "currency": "EUR",
+      "source": "manual"
+    }
+  ],
+  "note": "Source-of-truth expense ledger. Aggregations are computed by observatory/ledger.py \u2014 never hand-edited totals."
+}
--- a/projects/coulomb-pricing/data/payment_records.json
+++ b/projects/coulomb-pricing/data/payment_records.json
@@ -1,14 +1,14 @@
 {
  "version": 1,
-  "entries": [
-    {"id": "rev-2025-11", "period": "2025-11", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
-    {"id": "rev-2025-12", "period": "2025-12", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
-    {"id": "rev-2026-01", "period": "2026-01", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
-    {"id": "rev-2026-02", "period": "2026-02", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
-    {"id": "rev-2026-03", "period": "2026-03", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
-    {"id": "rev-2026-04", "period": "2026-04", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
-    {"id": "rev-2026-05", "period": "2026-05", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
-    {"id": "rev-2026-06", "period": "2026-06", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1}
+  "records": [
+    {"id": "pay-2025-11", "period": "2025-11", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
+    {"id": "pay-2025-12", "period": "2025-12", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
+    {"id": "pay-2026-01", "period": "2026-01", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
+    {"id": "pay-2026-02", "period": "2026-02", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
+    {"id": "pay-2026-03", "period": "2026-03", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
+    {"id": "pay-2026-04", "period": "2026-04", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
+    {"id": "pay-2026-05", "period": "2026-05", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1},
+    {"id": "pay-2026-06", "period": "2026-06", "gross_amount": "8.99", "fees_amount": "0.38", "refunds_amount": "0.00", "net_amount": "8.61", "currency": "EUR", "source": "manual", "member_count": 1}
  ],
-  "note": "Member payments begin November 2025. Stripe sync replaces manual entries in Sprint 3."
+  "note": "Member payment ledger from November 2025. Stripe sync replaces manual entries in Sprint 3."
 }
--- a/projects/coulomb-pricing/observatory/dashboard.py
+++ b/projects/coulomb-pricing/observatory/dashboard.py
@@ -9,26 +9,27 @@ from .load import (
    default_data_dir,
    latest_period,
    load_budget,
+    load_expense_records,
    load_membership,
-    load_monthly_platform_costs,
+    load_monthly_ledger,
+    load_payment_records,
    load_pricing_models,
    load_product,
-    load_revenue,
 )
-from .models import EconomicsSnapshot, LiquiditySummary, MonthlyPlatformCost, PricingModel, Product, RevenueEntry
+from .models import EconomicsSnapshot, LiquiditySummary, MonthlyPlatformCost, PaymentRecord, PricingModel, Product


 def _history_rows(
    monthly_costs: list[MonthlyPlatformCost],
-    revenue_entries: list[RevenueEntry],
+    payments: list[PaymentRecord],
    through_period: str,
 ) -> str:
-    revenue_by_period = {entry.period: entry for entry in revenue_entries}
+    payment_by_period = {record.period: record for record in payments}
    lines: list[str] = []
    for month in sorted(monthly_costs, key=lambda item: item.period):
        if month.period > through_period:
            continue
-        payment = revenue_by_period.get(month.period)
+        payment = payment_by_period.get(month.period)
        net_payment = payment.net_amount if payment else Decimal("0")
        period_net = net_payment - month.infrastructure_cost
        lines.append(
@@ -45,14 +46,15 @@ def render_dashboard(
    snapshot: EconomicsSnapshot,
    liquidity: LiquiditySummary,
    monthly_costs: list[MonthlyPlatformCost],
-    revenue_entries: list[RevenueEntry],
+    payments: list[PaymentRecord],
+    expense_count: int,
 ) -> str:
    active = next(m for m in models if m.id == product.active_pricing_model_id)
    registry_lines = "\n".join(
        f"| {model.id} | {model.name} | {model.model_type} | {model.status} |"
        for model in models
    )
-    history_lines = _history_rows(monthly_costs, revenue_entries, snapshot.period)
+    history_lines = _history_rows(monthly_costs, payments, snapshot.period)
    budget_state = (
        "over budget"
        if liquidity.remaining_budget < Decimal("0")
@@ -66,7 +68,9 @@ def render_dashboard(
 **Active pricing model:** {active.name} ({active.access_fee_amount} {active.currency}/{active.access_fee_cadence})

 > Platform costs accrue to the operator. Customer cost-pass-through billing is
-> **not active** in MVP — members pay subscription only.
+> **not active** in MVP — members pay subscription only. All totals are computed
+> programmatically from expense and payment record ledgers ({expense_count} expense
+> records).

 ## Key Metrics (current period)

@@ -114,9 +118,8 @@ _Revenue source: {snapshot.revenue_source}_

 - Product model (`data/product.json`)
 - Budget (`data/budget.json`)
- Pricing model registry (`data/pricing-models.json`)
- Platform costs (`data/costs.json`)
- Member payments (`data/revenue.json`)
+- Expense records (`data/expense_records.json`) — source of truth for costs
+- Payment records (`data/payment_records.json`)
 - Membership (`data/membership.json`)
 - Requirements (`REQUIREMENTS.md`)
 """
@@ -128,13 +131,16 @@ def generate_dashboard(data_dir: Path | None = None, period: str | None = None)
    budget = load_budget(root)
    models = load_pricing_models(root)
    members = load_membership(root)
-    revenue = load_revenue(root)
-    monthly_costs = load_monthly_platform_costs(root)
+    payments = load_payment_records(root)
+    expenses = load_expense_records(root)
+    monthly_costs = load_monthly_ledger(root)
    target_period = period or latest_period(monthly_costs)

-    snapshot = build_snapshot(target_period, product, models, members, revenue, monthly_costs)
-    liquidity = build_liquidity_summary(budget, revenue, monthly_costs, target_period)
-    return render_dashboard(product, models, snapshot, liquidity, monthly_costs, revenue)
+    snapshot = build_snapshot(target_period, product, models, members, payments, monthly_costs)
+    liquidity = build_liquidity_summary(budget, payments, monthly_costs, target_period)
+    return render_dashboard(
+        product, models, snapshot, liquidity, monthly_costs, payments, len(expenses)
+    )


 def main(argv: list[str] | None = None) -> int:
--- a/projects/coulomb-pricing/observatory/economics.py
+++ b/projects/coulomb-pricing/observatory/economics.py
@@ -4,15 +4,14 @@ from decimal import Decimal, ROUND_HALF_UP

 from .models import (
    Budget,
-    CostEntry,
    EconomicsSnapshot,
    LiquidityStatus,
    LiquiditySummary,
    MembershipRecord,
    MonthlyPlatformCost,
+    PaymentRecord,
    PricingModel,
    Product,
-    RevenueEntry,
 )

 TWOPLACES = Decimal("0.01")
@@ -23,16 +22,6 @@ def _quantize(value: Decimal, exp: Decimal = TWOPLACES) -> Decimal:
    return value.quantize(exp, rounding=ROUND_HALF_UP)


-def _convert_to_eur(amount: Decimal, currency: str, fx_rates: dict[str, Decimal]) -> Decimal:
-    if currency == "EUR":
-        return amount
-    if currency == "USD":
-        return amount * fx_rates.get("USD/EUR", Decimal("1"))
-    if currency == "ratio":
-        return amount
-    raise ValueError(f"unsupported currency for conversion: {currency}")
-
-
 def liquidity_status_for(net: Decimal) -> LiquidityStatus:
    if net < Decimal("0"):
        return "burning"
@@ -52,27 +41,10 @@ def active_pricing_model(models: list[PricingModel], product: Product) -> Pricin
    raise ValueError(f"active pricing model not found: {product.active_pricing_model_id}")


-def monthly_cost_from_rate_card(
-    cost_entries: list[CostEntry],
-    fx_rates: dict[str, Decimal],
-    gross_revenue: Decimal,
-    member_count: int,
-) -> Decimal:
-    total = Decimal("0")
-    for entry in cost_entries:
-        if entry.allocation == "flat":
-            total += _convert_to_eur(entry.amount, entry.currency, fx_rates)
-        elif entry.allocation == "percent_of_gross_revenue":
-            total += gross_revenue * entry.amount
-        elif entry.allocation == "per_active_member":
-            total += _convert_to_eur(entry.amount, entry.currency, fx_rates) * member_count
-    return _quantize(total)
-
-
-def revenue_for_period(period: str, revenue_entries: list[RevenueEntry]) -> RevenueEntry | None:
-    for entry in revenue_entries:
-        if entry.period == period:
-            return entry
+def payment_for_period(period: str, payments: list[PaymentRecord]) -> PaymentRecord | None:
+    for record in payments:
+        if record.period == period:
+            return record
    return None


@@ -81,16 +53,16 @@ def estimate_monthly_revenue(
    product: Product,
    models: list[PricingModel],
    members: list[MembershipRecord],
-    revenue_entries: list[RevenueEntry],
+    payments: list[PaymentRecord],
    monthly_costs: list[MonthlyPlatformCost],
 ) -> tuple[Decimal, Decimal, str]:
-    recorded = revenue_for_period(period, revenue_entries)
+    recorded = payment_for_period(period, payments)
    if recorded:
        return recorded.gross_amount, recorded.net_amount, recorded.source

    month = next((item for item in monthly_costs if item.period == period), None)
    if month and month.gross_revenue > 0:
-        return month.gross_revenue, month.gross_revenue, "derived_from_platform_history"
+        return month.gross_revenue, month.gross_revenue, "derived_from_ledger"

    model = active_pricing_model(models, product)
    count = active_members(members)
@@ -104,7 +76,7 @@ def periods_through(target: str, monthly_costs: list[MonthlyPlatformCost]) -> li

 def build_liquidity_summary(
    budget: Budget,
-    revenue_entries: list[RevenueEntry],
+    payments: list[PaymentRecord],
    monthly_costs: list[MonthlyPlatformCost],
    through_period: str,
 ) -> LiquiditySummary:
@@ -118,11 +90,9 @@ def build_liquidity_summary(
        month = cost_by_period[period]
        cumulative_infrastructure += month.infrastructure_cost
        cumulative_processing += month.payment_processing_cost
-        payment = revenue_for_period(period, revenue_entries)
+        payment = payment_for_period(period, payments)
        cumulative_payments += payment.net_amount if payment else Decimal("0")

-    # 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)
@@ -147,13 +117,13 @@ def build_snapshot(
    product: Product,
    models: list[PricingModel],
    members: list[MembershipRecord],
-    revenue_entries: list[RevenueEntry],
+    payments: list[PaymentRecord],
    monthly_costs: list[MonthlyPlatformCost],
 ) -> EconomicsSnapshot:
    month = next(item for item in monthly_costs if item.period == period)
    count = month.active_members if month.active_members else active_members(members)
    gross_revenue, net_revenue, revenue_source = estimate_monthly_revenue(
-        period, product, models, members, revenue_entries, monthly_costs
+        period, product, models, members, payments, monthly_costs
    )
    infrastructure = month.infrastructure_cost
    processing = month.payment_processing_cost
--- a/projects/coulomb-pricing/observatory/ledger.py
+++ b/projects/coulomb-pricing/observatory/ledger.py
@@ -0,0 +1,121 @@
+from __future__ import annotations
+
+from decimal import Decimal, ROUND_HALF_UP
+
+from .models import (
+    Budget,
+    ExpenseRecord,
+    MembershipRecord,
+    MonthlyPlatformCost,
+    PaymentRecord,
+)
+
+TWOPLACES = Decimal("0.01")
+
+
+def _quantize(value: Decimal) -> Decimal:
+    return value.quantize(TWOPLACES, rounding=ROUND_HALF_UP)
+
+
+def convert_to_eur(amount: Decimal, currency: str, fx_rates: dict[str, Decimal]) -> Decimal:
+    if currency == "EUR":
+        return amount
+    if currency == "USD":
+        return amount * fx_rates.get("USD/EUR", Decimal("1"))
+    raise ValueError(f"unsupported expense currency: {currency}")
+
+
+def aggregate_infrastructure_by_period(
+    expenses: list[ExpenseRecord],
+    fx_rates: dict[str, Decimal],
+    reporting_currency: str = "EUR",
+) -> dict[str, Decimal]:
+    if reporting_currency != "EUR":
+        raise ValueError("only EUR reporting currency is supported")
+
+    totals: dict[str, Decimal] = {}
+    for record in expenses:
+        if record.cost_class != "infrastructure":
+            continue
+        totals[record.period] = totals.get(record.period, Decimal("0")) + convert_to_eur(
+            record.amount, record.currency, fx_rates
+        )
+    return {period: _quantize(total) for period, total in totals.items()}
+
+
+def payment_processing_by_period(payments: list[PaymentRecord]) -> dict[str, Decimal]:
+    totals: dict[str, Decimal] = {}
+    for record in payments:
+        totals[record.period] = totals.get(record.period, Decimal("0")) + record.fees_amount
+    return {period: _quantize(total) for period, total in totals.items()}
+
+
+def _period_sort_key(period: str) -> tuple[int, int]:
+    year, month = period.split("-")
+    return int(year), int(month)
+
+
+def periods_from_budget_through_latest(
+    budget: Budget,
+    expenses: list[ExpenseRecord],
+    payments: list[PaymentRecord],
+) -> list[str]:
+    candidates = {budget.started}
+    candidates.update(record.period for record in expenses)
+    candidates.update(record.period for record in payments)
+    latest = max(candidates, key=_period_sort_key)
+    periods: list[str] = []
+    year, month = map(int, budget.started.split("-"))
+    end_year, end_month = map(int, latest.split("-"))
+    while (year, month) <= (end_year, end_month):
+        periods.append(f"{year}-{month:02d}")
+        month += 1
+        if month > 12:
+            month = 1
+            year += 1
+    return periods
+
+
+def active_members_for_period(period: str, members: list[MembershipRecord]) -> int:
+    period_start = f"{period}-01"
+    count = 0
+    for member in members:
+        if member.joined_at[:7] > period:
+            continue
+        if member.churned_at and member.churned_at[:7] < period:
+            continue
+        if member.status == "active" or (
+            member.churned_at and member.churned_at[:7] >= period
+        ):
+            count += 1
+    return count
+
+
+def build_monthly_ledger(
+    budget: Budget,
+    expenses: list[ExpenseRecord],
+    payments: list[PaymentRecord],
+    members: list[MembershipRecord],
+    fx_rates: dict[str, Decimal],
+) -> list[MonthlyPlatformCost]:
+    infrastructure = aggregate_infrastructure_by_period(expenses, fx_rates)
+    processing = payment_processing_by_period(payments)
+    payment_by_period = {record.period: record for record in payments}
+    rows: list[MonthlyPlatformCost] = []
+
+    for period in periods_from_budget_through_latest(budget, expenses, payments):
+        payment = payment_by_period.get(period)
+        rows.append(
+            MonthlyPlatformCost(
+                period=period,
+                infrastructure_cost=infrastructure.get(period, Decimal("0.00")),
+                payment_processing_cost=processing.get(period, Decimal("0.00")),
+                active_members=(
+                    payment.member_count
+                    if payment and payment.member_count
+                    else active_members_for_period(period, members)
+                ),
+                gross_revenue=payment.gross_amount if payment else Decimal("0.00"),
+            )
+        )
+    return rows
--- a/projects/coulomb-pricing/observatory/load.py
+++ b/projects/coulomb-pricing/observatory/load.py
@@ -4,16 +4,15 @@ import json
 from decimal import Decimal
 from pathlib import Path

-_ZERO = Decimal("0")
-
+from .ledger import build_monthly_ledger
 from .models import (
    Budget,
-    CostEntry,
+    ExpenseRecord,
    MembershipRecord,
    MonthlyPlatformCost,
+    PaymentRecord,
    PricingModel,
    Product,
-    RevenueEntry,
 )


@@ -67,55 +66,38 @@ def load_pricing_models(data_dir: Path | None = None) -> list[PricingModel]:
    ]


-def _parse_cost_entries(items: list[dict]) -> list[CostEntry]:
+def load_fx_rates(data_dir: Path | None = None) -> dict[str, Decimal]:
+    raw = _read_json((data_dir or default_data_dir()) / "expense_records.json")
+    return {pair: _money(rate) for pair, rate in raw.get("fx_rates", {}).items()}
+
+
+def load_expense_records(data_dir: Path | None = None) -> list[ExpenseRecord]:
+    raw = _read_json((data_dir or default_data_dir()) / "expense_records.json")
    return [
-        CostEntry(
+        ExpenseRecord(
            id=item["id"],
-            name=item["name"],
-            category=item["category"],
+            period=item["period"],
+            vendor=item["vendor"],
+            description=item["description"],
+            cost_class=item["cost_class"],
            amount=_money(item["amount"]),
            currency=item["currency"],
-            cadence=item["cadence"],
-            allocation=item["allocation"],
+            source=item["source"],
        )
-        for item in items
+        for item in raw["records"]
    ]


-def load_cost_rate_card(data_dir: Path | None = None) -> tuple[list[CostEntry], dict[str, Decimal]]:
-    raw = _read_json((data_dir or default_data_dir()) / "costs.json")
-    items = raw.get("rate_card", raw.get("entries", []))
-    fx = {pair: _money(rate) for pair, rate in raw.get("fx_rates", {}).items()}
-    return _parse_cost_entries(items), fx
-
-
-def load_monthly_platform_costs(data_dir: Path | None = None) -> list[MonthlyPlatformCost]:
-    raw = _read_json((data_dir or default_data_dir()) / "costs.json")
-    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"]),
-            )
-        )
-    return rows
-
-
-def load_revenue(data_dir: Path | None = None) -> list[RevenueEntry]:
-    raw = _read_json((data_dir or default_data_dir()) / "revenue.json")
+def load_payment_records(data_dir: Path | None = None) -> list[PaymentRecord]:
+    root = data_dir or default_data_dir()
+    path = root / "payment_records.json"
+    if not path.exists():
+        # Backward compatibility with legacy revenue.json
+        path = root / "revenue.json"
+    raw = _read_json(path)
+    items = raw.get("records", raw.get("entries", []))
    return [
-        RevenueEntry(
+        PaymentRecord(
            id=item["id"],
            period=item["period"],
            gross_amount=_money(item["gross_amount"]),
@@ -124,8 +106,9 @@ def load_revenue(data_dir: Path | None = None) -> list[RevenueEntry]:
            net_amount=_money(item["net_amount"]),
            currency=item["currency"],
            source=item["source"],
+            member_count=item.get("member_count", 0),
        )
-        for item in raw["entries"]
+        for item in items
    ]


@@ -143,5 +126,16 @@ def load_membership(data_dir: Path | None = None) -> list[MembershipRecord]:
    ]


+def load_monthly_ledger(data_dir: Path | None = None) -> list[MonthlyPlatformCost]:
+    root = data_dir or default_data_dir()
+    return build_monthly_ledger(
+        load_budget(root),
+        load_expense_records(root),
+        load_payment_records(root),
+        load_membership(root),
+        load_fx_rates(root),
+    )
+
+
 def latest_period(monthly_costs: list[MonthlyPlatformCost]) -> str:
    return max(item.period for item in monthly_costs)
--- a/projects/coulomb-pricing/observatory/models.py
+++ b/projects/coulomb-pricing/observatory/models.py
@@ -4,7 +4,7 @@ from dataclasses import dataclass
 from decimal import Decimal
 from typing import Literal

-CostCategory = Literal["fixed", "variable"]
+ExpenseClass = Literal["infrastructure", "payment_processing"]
 MemberStatus = Literal["active", "churned", "paused"]
 PricingModelStatus = Literal["active", "candidate", "retired"]
 LiquidityStatus = Literal["burning", "neutral", "generating"]
@@ -33,14 +33,28 @@ class PricingModel:


@dataclass(frozen=True)
-class CostEntry:
+class ExpenseRecord:
    id: str
-    name: str
-    category: CostCategory
+    period: str
+    vendor: str
+    description: str
+    cost_class: ExpenseClass
    amount: Decimal
    currency: str
-    cadence: str
-    allocation: str
+    source: str
+
+
+@dataclass(frozen=True)
+class PaymentRecord:
+    id: str
+    period: str
+    gross_amount: Decimal
+    fees_amount: Decimal
+    refunds_amount: Decimal
+    net_amount: Decimal
+    currency: str
+    source: str
+    member_count: int = 0


@dataclass(frozen=True)
@@ -63,18 +77,6 @@ class Budget:
    started: str


-@dataclass(frozen=True)
-class RevenueEntry:
-    id: str
-    period: str
-    gross_amount: Decimal
-    fees_amount: Decimal
-    refunds_amount: Decimal
-    net_amount: Decimal
-    currency: str
-    source: str
-
-
@dataclass(frozen=True)
 class MembershipRecord:
    id: str
--- a/projects/coulomb-pricing/reports/economics-2026-06.md
+++ b/projects/coulomb-pricing/reports/economics-2026-06.md
@@ -5,7 +5,9 @@
 **Active pricing model:** Standard Membership (8.99 EUR/monthly)

 > Platform costs accrue to the operator. Customer cost-pass-through billing is
-> **not active** in MVP — members pay subscription only.
+> **not active** in MVP — members pay subscription only. All totals are computed
+> programmatically from expense and payment record ledgers (48 expense
+> records).

 ## Key Metrics (current period)

@@ -13,13 +15,13 @@
 |--------|------:|
 | Active members | 1 |
 | Member payments (gross) | 8.99 EUR |
-| Infrastructure cost | 72.20 EUR |
+| Infrastructure cost | 69.44 EUR |
 | Payment processing cost | 0.38 EUR |
-| Total platform cost | 72.58 EUR |
-| Platform cost per member | 72.58 EUR |
-| Period gross margin | -63.59 EUR |
-| Period gross margin % | -707.3% |
-| Period net liquidity | -63.59 EUR (burning) |
+| Total platform cost | 69.82 EUR |
+| Platform cost per member | 69.82 EUR |
+| Period gross margin | -60.83 EUR |
+| Period gross margin % | -676.6% |
+| Period net liquidity | -60.83 EUR (burning) |

 _Period net liquidity = net member payments − infrastructure cost (processing fees already netted from payments)._  
 _Revenue source: manual_
@@ -30,33 +32,33 @@ _Revenue source: manual_
 |--------|------:|
 | Initial budget | 1000.00 EUR |
 | Cumulative member payments (net) | 68.88 EUR |
-| Cumulative infrastructure cost | 1155.20 EUR |
+| Cumulative infrastructure cost | 1111.04 EUR |
 | Cumulative payment processing | 3.04 EUR |
-| Cumulative total platform cost | 1158.24 EUR |
-| Cumulative net liquidity | -1086.32 EUR (burning) |
-| Remaining budget | -86.32 EUR (over budget) |
+| Cumulative total platform cost | 1114.08 EUR |
+| Cumulative net liquidity | -1042.16 EUR (burning) |
+| Remaining budget | -42.16 EUR (over budget) |
 | Months tracked | 16 |

 ## Monthly History

 | Period | Members | Gross revenue | Infrastructure | Processing | Total platform | Net liquidity |
 |--------|--------:|--------------:|---------------:|-----------:|---------------:|--------------:|
-| 2025-03 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-04 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-05 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-06 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-07 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-08 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-09 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-10 | 0 | 0.00 | 72.20 | 0.00 | 72.20 | -72.20 |
-| 2025-11 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
-| 2025-12 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
-| 2026-01 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
-| 2026-02 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
-| 2026-03 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
-| 2026-04 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
-| 2026-05 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
-| 2026-06 | 1 | 8.99 | 72.20 | 0.38 | 72.58 | -63.59 |
+| 2025-03 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-04 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-05 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-06 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-07 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-08 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-09 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-10 | 0 | 0.00 | 69.44 | 0.00 | 69.44 | -69.44 |
+| 2025-11 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |
+| 2025-12 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |
+| 2026-01 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |
+| 2026-02 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |
+| 2026-03 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |
+| 2026-04 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |
+| 2026-05 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |
+| 2026-06 | 1 | 8.99 | 69.44 | 0.38 | 69.82 | -60.83 |

 ## Pricing Model Registry

@@ -70,8 +72,7 @@ _Revenue source: manual_

 - Product model (`data/product.json`)
 - Budget (`data/budget.json`)
- Pricing model registry (`data/pricing-models.json`)
- Platform costs (`data/costs.json`)
- Member payments (`data/revenue.json`)
+- Expense records (`data/expense_records.json`) — source of truth for costs
+- Payment records (`data/payment_records.json`)
 - Membership (`data/membership.json`)
 - Requirements (`REQUIREMENTS.md`)
--- a/projects/coulomb-pricing/tests/test_economics.py
+++ b/projects/coulomb-pricing/tests/test_economics.py
@@ -3,20 +3,17 @@ from __future__ import annotations
 from decimal import Decimal
 from pathlib import Path

-from observatory.economics import (
-    active_members,
-    build_liquidity_summary,
-    build_snapshot,
-    monthly_cost_from_rate_card,
-)
+from observatory.economics import active_members, build_liquidity_summary, build_snapshot
+from observatory.ledger import aggregate_infrastructure_by_period, build_monthly_ledger
 from observatory.load import (
    load_budget,
-    load_cost_rate_card,
+    load_expense_records,
+    load_fx_rates,
    load_membership,
-    load_monthly_platform_costs,
+    load_monthly_ledger,
+    load_payment_records,
    load_pricing_models,
    load_product,
-    load_revenue,
 )

 DATA_DIR = Path(__file__).resolve().parent.parent / "data"
@@ -27,52 +24,80 @@ def test_active_members_counts_only_active_status() -> None:
    assert active_members(members) == 1


-def test_rate_card_splits_infrastructure_and_payment_processing() -> None:
-    rate_card, fx_rates = load_cost_rate_card(DATA_DIR)
-    infrastructure = monthly_cost_from_rate_card(rate_card, fx_rates, Decimal("0"), 0)
-    with_revenue = monthly_cost_from_rate_card(rate_card, fx_rates, Decimal("8.99"), 1)
-    assert infrastructure == Decimal("72.20")
-    assert with_revenue == Decimal("72.58")
-    assert with_revenue - infrastructure == Decimal("0.38")
+def test_infrastructure_aggregated_from_expense_records() -> None:
+    expenses = load_expense_records(DATA_DIR)
+    fx = load_fx_rates(DATA_DIR)
+    totals = aggregate_infrastructure_by_period(expenses, fx)
+
+    assert totals["2025-03"] == Decimal("69.44")
+    assert totals["2026-06"] == Decimal("69.44")
+    # Bubble $32 @ 0.92 = 29.44 + 15 domains + 25 overhead
+    bubble_eur = Decimal("32.00") * Decimal("0.92")
+    assert bubble_eur == Decimal("29.44")


-def test_build_snapshot_june_2026_avoids_stripe_double_count_in_liquidity() -> None:
+def test_monthly_ledger_computes_processing_from_payment_records() -> None:
+    ledger = load_monthly_ledger(DATA_DIR)
+    june = next(row for row in ledger if row.period == "2026-06")
+    march = next(row for row in ledger if row.period == "2025-03")
+
+    assert march.infrastructure_cost == Decimal("69.44")
+    assert march.payment_processing_cost == Decimal("0.00")
+    assert march.gross_revenue == Decimal("0.00")
+    assert june.infrastructure_cost == Decimal("69.44")
+    assert june.payment_processing_cost == Decimal("0.38")
+    assert june.gross_revenue == Decimal("8.99")
+
+
+def test_build_snapshot_june_2026_uses_ledger_not_hand_totals() -> None:
    product = load_product(DATA_DIR)
    models = load_pricing_models(DATA_DIR)
    members = load_membership(DATA_DIR)
-    revenue = load_revenue(DATA_DIR)
-    monthly_costs = load_monthly_platform_costs(DATA_DIR)
+    payments = load_payment_records(DATA_DIR)
+    ledger = load_monthly_ledger(DATA_DIR)

-    snapshot = build_snapshot("2026-06", product, models, members, revenue, monthly_costs)
+    snapshot = build_snapshot("2026-06", product, models, members, payments, ledger)

-    assert snapshot.monthly_infrastructure_cost == Decimal("72.20")
+    assert snapshot.monthly_infrastructure_cost == Decimal("69.44")
    assert snapshot.monthly_payment_processing_cost == Decimal("0.38")
-    assert snapshot.monthly_total_platform_cost == Decimal("72.58")
-    assert snapshot.period_net_liquidity == Decimal("-63.59")
-    assert snapshot.gross_margin == Decimal("-63.59")
+    assert snapshot.monthly_total_platform_cost == Decimal("69.82")
+    assert snapshot.period_net_liquidity == Decimal("-60.83")
+    assert snapshot.gross_margin == Decimal("-60.83")


-def test_liquidity_summary_uses_infrastructure_only_for_cumulative_burn() -> None:
+def test_liquidity_summary_aggregates_ledgers_deterministically() -> None:
    budget = load_budget(DATA_DIR)
-    revenue = load_revenue(DATA_DIR)
-    monthly_costs = load_monthly_platform_costs(DATA_DIR)
+    payments = load_payment_records(DATA_DIR)
+    ledger = load_monthly_ledger(DATA_DIR)

-    summary = build_liquidity_summary(budget, revenue, monthly_costs, "2026-06")
+    summary = build_liquidity_summary(budget, payments, ledger, "2026-06")

-    assert summary.cumulative_infrastructure_cost == Decimal("1155.20")
+    assert summary.cumulative_infrastructure_cost == Decimal("1111.04")
    assert summary.cumulative_payment_processing_cost == Decimal("3.04")
-    assert summary.cumulative_total_platform_cost == Decimal("1158.24")
+    assert summary.cumulative_total_platform_cost == Decimal("1114.08")
    assert summary.cumulative_member_payments == Decimal("68.88")
-    assert summary.cumulative_net_liquidity == Decimal("-1086.32")
-    assert summary.remaining_budget == Decimal("-86.32")
+    assert summary.cumulative_net_liquidity == Decimal("-1042.16")
+    assert summary.remaining_budget == Decimal("-42.16")
    assert summary.liquidity_status == "burning"
    assert summary.months_tracked == 16


-def test_dashboard_renders_split_cost_columns() -> None:
+def test_build_monthly_ledger_matches_loader() -> None:
+    budget = load_budget(DATA_DIR)
+    expenses = load_expense_records(DATA_DIR)
+    payments = load_payment_records(DATA_DIR)
+    members = load_membership(DATA_DIR)
+    fx = load_fx_rates(DATA_DIR)
+
+    assert build_monthly_ledger(budget, expenses, payments, members, fx) == load_monthly_ledger(
+        DATA_DIR
+    )
+
+
+def test_dashboard_notes_expense_record_source() -> None:
    from observatory.dashboard import generate_dashboard

    report = generate_dashboard(DATA_DIR, "2026-06")
-    assert "Cumulative infrastructure cost" in report
-    assert "1155.20" in report
-    assert "-86.32" in report
+    assert "expense and payment record ledgers" in report
+    assert "1111.04" in report
+    assert "-42.16" in report