# Coulomb MVP — Liquidity & Cost Requirements

## Context

Coulomb Social carries **operator platform costs** (Bubble.io, domains, Stripe
fees, future OpenRouter usage) while **customer cost-pass-through billing is not
active yet**. Members pay a flat subscription; they are not billed for
underlying platform spend.

The Economic Observatory must make the resulting **liquidity burn** visible.

## Requirements

### LQ-001 — Platform cost ledger

Record monthly platform costs from project start (March 2025), including fixed
infrastructure and payment-provider variable fees when member revenue exists.

### LQ-002 — Member payment ledger

Record member subscription payments from first payment month (November 2025),
separate from platform cost accrual.

### LQ-003 — Budget tracking

Maintain an operator liquidity budget (initial: **€1,000**) and compute
remaining budget after cumulative platform spend minus cumulative member
payments received.

### LQ-004 — Liquidity position

Report whether the project is **burning**, **neutral**, or **generating**
liquidity each period:

- `period_net = member_payments - platform_costs`
- `cumulative_net = sum(period_net)`
- `remaining_budget = initial_budget + cumulative_net`

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
(OpenRouter per member, usage overage) is observatory-only until a later phase
introduces customer-visible credits or usage billing.

### LQ-006 — Historical dashboard

Economics Dashboard must show:

- Current-period economics (revenue, platform cost, margin)
- Cumulative liquidity summary (budget, burn, remaining)
- Monthly history table from March 2025

## Data sources (current)

| Registry | Path |
|----------|------|
| Budget | `data/budget.json` |
| Platform costs | `data/costs.json` (`rate_card` + `monthly_history`) |
| Member payments | `data/revenue.json` |
| Membership | `data/membership.json` |

Future sprints replace manual history with Bubble, Stripe, and OpenRouter imports
while preserving the same liquidity semantics.