amadan
business model: durability axis — litestream TTL scales with payment
Baseline $1 apps: 5-min sync + guaranteed flush at hibernation. Tighter TTL down to 1-2s billed as metered replication writes at S3 cost ×5. Fleet excluded (their storage, their cadence). Eleven mechanism.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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docs/superpowers/specs/2026-08-13-carloku-business-model-design.md+32 −1
diff --git a/docs/superpowers/specs/2026-08-13-carloku-business-model-design.md b/docs/superpowers/specs/2026-08-13-carloku-business-model-design.md| index f852db054..3c62abb13 100644 |
| --- a/docs/superpowers/specs/2026-08-13-carloku-business-model-design.md |
| +++ b/docs/superpowers/specs/2026-08-13-carloku-business-model-design.md |
| @@ -35,7 +35,7 @@ dashboard, not published commitments. |
| | --- | --- | --- | --- | |
| | **Try** | everyone, forever | $0 (our permanent marketing cost) | 1 tiny hosted app; hard caps (1 GB egress/mo, 250 MB storage); sleeps aggressively | |
| | **Free pool** | hobbyists | $0 (pool-funded — see below) | generous limits (10 GB egress, 1 GB storage shape) while the pool covers it | |
| -| **Hosted** | indies, agencies | per app + usage | **$1/app-month baseline** + **$0.004/instance-hour** (a hibernating app ≈ $1/mo; an always-on app ≈ $3.90/mo — hibernation is the product and the price says so); egress $0.15/GB and storage $0.05/GB-month past allowances | |
| +| **Hosted** | indies, agencies | per app + usage | **$1/app-month baseline** + **$0.004/instance-hour** (a hibernating app ≈ $1/mo; an always-on app ≈ $3.90/mo — hibernation is the product and the price says so); egress $0.15/GB and storage $0.05/GB-month past allowances; durability TTL baseline 5 min + flush-on-hibernate, tighter TTL metered at S3-write cost × 5 (see Durability axis) | |
| | **Fleet** | self-hosting companies (Eleven shape), edge/IoT (Pi shape), agencies on own metal | per box, tiered by device class | **$5/box-month server class**, **$1/box-month device class**; 10+ boxes → 40% off; relay egress $0.15/GB past 20 GB/box/mo; direct-served traffic free (unmetered by construction); **apps free** | |
| | **Dedicated** | big orgs wanting the efficiency without self-hosting | per dedicated box we run | **cost × multiple** all-in; at the standard 5× a t4g.small is ≈ $95/box-mo and a t4g.medium ≈ $170 (2026-08 all-in costs ≈ $19/$34) — the dedicated multiple is expected to settle LOWER than 5× (managed capacity competes with raw EC2 at ~$13); it is a first-class knob. **Apps free**; metered egress/storage on top; idle included — they rent the whole box, so no idle-smearing question exists | |
| @@ -104,6 +104,37 @@ commons, which is a story we can tell. |
| the region count IS the box count, which keeps the price sheet honest |
| and makes HA/residency a natural multiplier instead of a negotiation. |
| +## Durability axis — TTL scales with payment (Paul, 2026-08-15) |
| + |
| +The Eleven mechanism applied to storage durability. A tenant app's data |
| +durability is defined by its litestream replication TTL, and the TTL is |
| +a priced choice because its cost driver is S3 PUTs: |
| + |
| +- **Baseline (included in $1/app-month):** long TTL (anchor: 5-minute |
| + sync) plus a **guaranteed flush at hibernation** — the durability |
| + promise every app gets is "hibernate = durable". Between periodic |
| + syncs, a box loss can cost up to one TTL of writes; that bound is the |
| + product tier, stated plainly. Cost to us ≈ $0.04/month even for a |
| + busy app (8.6k PUTs at $0.005/1k) — safely inside the $1. |
| +- **Paid tightness:** the customer picks a shorter TTL, down to 1–2 s |
| + (continuous litestream), and pays **metered replication writes at S3 |
| + write cost × 5** (~$0.025/1k PUTs). Litestream only uploads on |
| + change, so the meter charges actual sync PUTs, not wall-clock: a |
| + worst-case continuous writer at 1 s TTL ≈ 2.6M PUTs/mo ≈ $13 cost → |
| + ≈ $65 billed; a sporadic writer at the same TTL pays cents. Fair by |
| + construction — you pay for the durability you actually consumed. |
| +- **Scope:** applies where OUR buckets carry the writes — hosted and |
| + dedicated. Fleet boxes replicate to the customer's own storage, so |
| + their durability cadence is their business and their bill (consistent |
| + with "direct-served traffic never bills": the meter boundary is the |
| + cost boundary). |
| +- **Machinery this needs** (joins the follow-up spec): per-app/instance |
| + litestream sync-interval config, the hibernate-flush guarantee as a |
| + tested invariant, and per-tenant S3 write metering — the same meter |
| + already named as the litestream-spam guard, now also a revenue axis |
| + (`durability_writes_1k` in the meter vocabulary, priced in the rate |
| + sheet). |
| + |
| ## Unit maths (2026-08 real data) |
| - Whole flagship fleet (4 × t4g.small in IE/US/UK/AU + overheads): |