RFD 1080 details: the numbers, and where they came from
Source prices
From fly.io/docs/about/pricing/, the published rates this breakdown uses directly:
| Resource | Per-second | Per-month |
|---|---|---|
shared-cpu-1x, 256MB |
$0.00000078 | $2.02 |
shared-cpu-1x, 512MB |
$0.00000128 | $3.32 |
| Volume storage | — | $0.15/GB |
Hourly = per-second × 3600. Yearly = per-month × 12, the number Fly itself bills against, not hourly × 8760 (the two differ slightly because a month is not exactly 730 hours; the per-month figure is the one Fly actually charges).
This deployment’s real sizes, checked live
flyctl machine list and flyctl volumes list, run against all three apps, the same session these prices apply to:
| App | Machine(s) | Volume |
|---|---|---|
weftspun-studio |
1× shared-cpu-1x, 512MB |
3GB |
weftspun-character-taxonomy |
1× shared-cpu-1x, 512MB |
1GB |
weftspun-usd-viewer |
1× shared-cpu-1x, 256MB |
none |
weftspun-usd-viewer started as Fly’s default 2-machine HA pair (zero-downtime deploys); scaled to one (min_machines_running = 0 in its own fly.toml, then flyctl scale count 1) per the user’s own choice of cost over restart-window downtime.
No dedicated IPv4 anywhere (checked with flyctl ips list against all three apps): only shared IPv4 and free dedicated IPv6, so no extra per-app IP charge applies.
The breakdown, hourly / monthly / yearly
| App | Hourly | Monthly | Yearly |
|---|---|---|---|
weftspun-studio (machine) |
$0.004608 | $3.32 | $39.84 |
weftspun-studio (3GB volume) |
$0.000616 | $0.45 | $5.40 |
weftspun-character-taxonomy (machine) |
$0.004608 | $3.32 | $39.84 |
weftspun-character-taxonomy (1GB volume) |
$0.000205 | $0.15 | $1.80 |
weftspun-usd-viewer (machine) |
$0.002808 | $2.02 | $24.24 |
| Total | $0.012845 | $9.26 | $111.12 |
Volume hourly figures divide the monthly rate by 730 (Fly’s own average hours-per-month), since Fly bills Volumes monthly, not per-second; machine hourly figures are the real per-second billing rate × 3600, both shown for a like-for-like row.
What this excludes
- Outbound bandwidth. Usage-based, not a fixed size like a Machine or a Volume. Fly’s free tier covers a baseline before per-GB egress billing starts; this deployment’s actual traffic was not measured this session.
- Tigris. RFD 1073’s still-open fetch-path work (
apps/usd_viewer_app/fetching gallery assets from Tigris instead of baking them into its own image) would add real, usage-based storage and bandwidth cost once built. Not yet built, so not yet billed, so not in this total. taskweft-mcp, a fourth already-deployed Fly app in the same org, unrelated to the three this RFD scopes (weftspun-studio,weftspun-character-taxonomy,weftspun-usd-viewer). Its own cost is real but out of this RFD’s scope.