--- name: cost-check description: > Estimate the monthly cost of a Pulumi or Terraform project with the FinFocus CLI, flag expensive resources, cost increases, and total cost against thresholds in .cost-check.yml, and write a COST_CHECK.md report. Reads machine-readable JSON, checks the CLI version, and names what to do when the CLI, a plugin, credentials, or a plan is missing. Use when checking infrastructure costs, reviewing the cost impact of a change, or gating CI on cost. Triggers on: "cost check", "estimate infrastructure cost", "how much will this cost", "flag expensive resources", "cost threshold", "COST_CHECK.md". --- # Cost Check Run `finfocus cost projected` on the current project, apply thresholds, and write `COST_CHECK.md`. Install: `npx skills add rshade/finfocus -s cost-check`. **Required CLI: finfocus v0.5.0 or newer.** Update this line with the release the skill was last run against. **Core principle:** read the numbers the CLI returns. Never estimate a price by hand, never parse the table output, and never report an unpriced resource as `$0`. ## 1. Detect the input | Found in the project | Input | Status | | --- | --- | --- | | `Pulumi.yaml` or `Pulumi.yml` (this directory or a parent) | `--pulumi-json plan.json`, or auto-detect | supported | | `terraform.tfstate` | `--terraform-state terraform.tfstate` | supported, state only | | `*.tf` with no state file | none | not supported: Terraform plan input is not available as of v0.5.0 | Terraform: the CLI prices what is in the state file, so a state that does not exist yet or is stale gives no estimate for the pending change. Say so in the report. Do not run `terraform plan` and do not convert its output. When Terraform plan input ships, edit this table and `references/cli-contract.md`. If a Pulumi project and a Terraform state are both present, run each separately. If nothing is found, stop: "No Pulumi project or Terraform state found in this directory." ## 2. Preflight ```bash command -v finfocus finfocus --version finfocus plugin list --output json ``` - No binary: stop, name the failure, point to the `finfocus-install` skill. - Version older than the required one: stop and print both versions. A build such as `v0.5.0-6-g3cb7ded` counts as v0.5.0. An unparseable version, or `0.1.0` with no leading `v` (an unstamped source build), continues, and the report says "version unverified". - `plugin list` returns `[]`: no plugin is installed. Continue. `cost projected` can still price resources from local YAML specs, so an empty list does not mean nothing is priced. Step 5 decides whether an estimate exists. Point to `finfocus-install` for the missing prices. Failure handling for every step is in [references/failure-modes.md](references/failure-modes.md). ## 3. Load thresholds Read `.cost-check.yml` in the project root. Absent keys use the defaults. Format, defaults, and CI exit codes: [references/thresholds.md](references/thresholds.md). ## 4. Run the CLI Prefer a plan file the user already has. Otherwise the CLI runs `pulumi preview --json` itself, so tell the user before it starts. ```bash finfocus cost projected --pulumi-json plan.json --output json finfocus cost projected --output json --stack finfocus cost projected --terraform-state terraform.tfstate --output json ``` Keep stdout and stderr apart and record the exit code. Stdout is one JSON document. Stderr carries a JSON error with `error_code` and `message`. Field names, exit codes, and the optional `cost forecast` call are in [references/cli-contract.md](references/cli-contract.md). ## 5. Validate before trusting the numbers 1. Exit code `0`, or a budget exit with a JSON document on stdout. Any other exit: stop with the `error_code` and `message`. 2. `finfocus.resources` is non-empty. 3. A resource with an `error` object is **unpriced**. List it. Never add it as `0`. Also read `finfocus.errors[]`: when the old side of an update or replacement fails to price, the failure appears only there, and the diff treats that baseline as `0`. List each entry. Mark the delta of every affected resource, and any plan increase flag that depends on it, **unavailable**. Never report them as a lower bound. 4. Every resource unpriced: stop. This is the zero-cost case. Point to the `finfocus-diagnose` skill ("Zero cost"). 5. A resource with no `error` and `monthly` of `0` is a real result. Report it. ## 6. Flag 1. Expensive resource: `monthly` above `thresholds.resource`. 2. Increase: `finfocus.diff.totalDelta` above `thresholds.increase`. A plan with `totalBefore` of `0`, such as one that only creates resources, is valid, so always make this check. Also flag the percentage above `thresholds.increase_pct` (`totalDelta / totalBefore * 100`), but only when `totalBefore` is above 0; otherwise skip the percentage check and say so. Skip both when step 5 marked the baseline unavailable. 3. Total: `finfocus.summary.totalMonthly` above `thresholds.total`. 4. Unpriced resources are not a threshold flag. They make every total a lower bound, and the report says that. If `currency` is not the thresholds file's currency (default `USD`), skip the dollar flags and say why. ## 7. Report Print a terminal summary, then write `COST_CHECK.md` from [references/report-template.md](references/report-template.md). Run `markdownlint COST_CHECK.md` when the tool is installed. End with one line CI can match: ```text COST_CHECK_RESULT: PASS | FLAGGED | ERROR () ``` Show the total, the flag counts, the top flagged items, the delta, and the unpriced list. Then ask whether to adjust thresholds or look at an item.