Savings: simulate and ledger

Two commands, two questions:

deploys simulate [--days 30]: What would auto-deploy cost me a month, next to deploying once a day? Works before you turn anything off.
deploys ledger: What has turning auto-deploy off saved so far? Counts from the day you turned it off.

Both need gh (logged in), because they count pushes on GitHub. Add --json for the machine answer. In the app: the Simulator (a banner before anything is turned off, and Settings → Costs) and the Ledger ("≈ $X saved since …", per project).

Every number is an estimate and shows "≈". The JSON says how it was made (method).

How it is estimated#

pushes to the deploy branch × the project's average build

Pushes. From GitHub's activity list for the deploy branch (repos/{repo}/activity: push, force_push, pr_merge, merge_queue_merge). Where that cannot be read, commits on the branch stand in. One push can carry several commits, so that count is an upper bound. basis says which one was used.
Average build. The mean duration of the project's last 20 finished builds (Vercel: READY; Render: live or deactivated). Failed and canceled builds are not measured.
Price per build, the first one that is known:
1. Vercel billing (deploys costs, last 7 days): billed build dollars / builds of that project (vercel-billing).
2. The team's price per build minute (billed build dollars / billed build minutes over all Vercel projects with billing) × the average build (vercel-team-rate).
3. A rate you set (rate-setting): DEPLOYS_VERCEL_USD_PER_MIN for one Vercel build minute, DEPLOYS_RENDER_USD_PER_MIN for one Render pipeline minute.
Render has no billing API. Without DEPLOYS_RENDER_USD_PER_MIN, Render shows pipeline minutes only, and the dollars stay null ("?").

simulate: every push in the window counts as one build ("auto-deploy"). "Once a day" counts one build on each day that had a push. Both are scaled from the window (--days, 1 to 90) to 30 days.

ledger: from the day auto-deploy was turned off (per project), every push whose commit was never built counts as a skipped build. Projects whose auto-deploy was never turned off here are left out.

Examples#

deploys simulate

Estimate over the last 30 days, per month:
  web (vercel): 6 pushes; auto-deploy ≈ $1.2, 18 build minutes; once a day ≈ $0.4
  api (render): 4 pushes; auto-deploy ≈ ?, 20 pipeline minutes; once a day ≈ ?
Auto-deploy would cost ≈ $1.2 a month; deploying once a day ≈ $0.4.

DEPLOYS_RENDER_USD_PER_MIN=0.01 deploys simulate --days 14
deploys ledger

Since 2026-01-20: ≈ $0.8 saved, 6 builds skipped (12 Vercel build minutes, 10 Render pipeline minutes).
  web (vercel), off since 2026-01-20: 4 of 5 pushes not built, ≈ $0.8, 12 build minutes
  api (render), off since 2026-01-25: 2 of 3 pushes not built, ≈ ?, 10 pipeline minutes

deploys ledger --json | jq '.total.usd'

JSON#

Both: estimate (always true), kind (simulate or ledger), currency (USD), generatedAt, method, projects, total.

Per project, both:

Field	Meaning
`platform`, `name`	`vercel` or `render`, and the project
`unit`	`build minutes` (Vercel) or `pipeline minutes` (Render)
`basis`	`pushes` or `commits` (upper bound); `null` if GitHub could not be read
`problem`	why a number is missing, or `null`
`pushes`	pushes counted in the window
`avgBuildMinutes`, `buildsMeasured`	the average build and how many builds it is from (at most 20)
`usdPerBuild`, `priceSource`	the price of one build, and `vercel-billing`, `vercel-team-rate`, `rate-setting` or `null`

simulate (days, teamUsdPerBuildMinute at the top):

Field	Meaning
`auto`	auto-deploy is on now
`activeDays`, `pushesPerDay`	days with a push, pushes per day
`autoMonth`, `dailyMonth`, `savingMonth`	`{builds, minutes, usd}` per month: auto-deploy, once a day, the difference
`total.*Month`	`{usd, vercelMinutes, renderMinutes, builds}` over all projects
`total.usdComplete`	`false` if a project with pushes has no price, so `usd` is too low

ledger (since, days since the first project was turned off, at the top):

Field	Meaning
`offAt`, `offDay`	when auto-deploy was turned off
`builds`, `skipped`	builds since then, and pushes never built
`savedMinutes`, `savedUsd`, `builtUsd`	the skipped builds in minutes and dollars, and what the builds that did run cost
`skippedPushes`	the last 20 skipped pushes, `{day, sha}`
`total`	`skipped`, `pushes`, `builds`, `usd`, `builtUsd`, `vercelMinutes`, `renderMinutes`, `usdComplete`

Limits#

An estimate, not a bill. Your invoice from Vercel or Render is what counts.
Vercel and Render only. The numbers come from each host's list of past deploys and a price per build minute, and only these two are wired up so far. The opt-in hosts (Netlify, Cloudflare Pages, AWS Amplify, DigitalOcean, Coolify, deploy hooks) do not appear in simulate or ledger, not even as a count; there is no date for that yet. Until then, their own dashboards show the build minutes.
Every build is priced at the average. Build caches, larger machines and included minutes are not in it.
Vercel billing covers the last 7 days only. A project without billed builds there falls back to the team rate.
The commit fallback overcounts when a push carries several commits.
A deploy started by a hook or a workflow counts as built; the ledger then does not count that push as saved.
Without gh, or without a known repo and branch, a project has no numbers (problem says why).