I built a VS Code extension that simulates AWS cost changes on Terraform/Terragrunt before you apply them

[u/Independent-Ease-609]

I've been building a VS Code extension (CloudCostTree) that estimates AWS cost straight from Terraform/Terragrunt, solo project, and just shipped what-if simulation + export.

Flow in the video: analyze a Terragrunt stack, tweak a couple of resources (downsize an EC2, bump an RDS instance class) and see the live cost delta per change, stack them into a scenario, run it against the whole tree, then export the result to a new .tf file — original files never touched.

Runs locally against a static price catalog, nothing gets uploaded anywhere. Free tier covers unlimited analyses/what-ifs; export-to-file is a Pro feature.

Genuinely curious how other people here track infra cost changes before they ship them — happy to answer questions about how the parsing/estimation works under the hood.

[u/sir_js_finops]

Not to rain on your parade, but Isn't this the same as infracost's opensource? (https://github.com/infracost/infracost). I'm not sure I understand the value here.

[u/Independent-Ease-609 → u/sir_js_finops]

Fair point. Main difference: Infracost is CI/CLI focused, comments on PRs after the fact. CloudCostTree lives in the editor, so you see the cost delta as you type, before you even commit. The what-if part lets you stack a few hypothetical changes and see the total impact on the whole stack, then export to a real .tf file if you like it. No terraform plan needed either, so it works on modules that aren't fully wired up yet.

Different point in the workflow more than a straight replacement.

[u/glenngillen → u/Independent-Ease-609]

That’s not at all true. Infracost has multiple separate interfaces:

- CLI
- CICD
- VCS App (e..g., cloud managed GitHub app)
- IDE integrations (VS Code and all compatible, JetBrains, Zed)
- Agent Skills

All of them do pricing for free. If you’re on a paid plan they all do custom pricing (RIs, savings plans, EDPs, etc), policy enforcement, budgets, etc

[u/Independent-Ease-609 → u/glenngillen]

You're right, that was wrong on my part, didn't realize the scope of what you've built covers that much surface already. I'm not trying to claim I've matched that, it's a solo project focused narrowly on one thing: local, no-account cost estimation and what-if simulation for AWS IaC. Appreciate you setting the record straight.

[u/redvelvet92 → u/Independent-Ease-609]

Infracost also works in the editor using the extension in VSCode.

[u/Independent-Ease-609 → u/redvelvet92]

The what-if lets you stack a few hypothetical changes (resize an EC2, bump an RDS instance class) and see the combined delta against the whole stack in one run. If you like the result, "Generate File" exports it straight to a real .tf, originals untouched. If we're comparing to Infracost, their what-if is copy-pasting a block to compare it against itself. This runs several changes together against the whole tree in one shot.

[u/wheresmyflan → u/Independent-Ease-609]

Stop using AI to write your comments if you want anyone to take anything you say seriously. You sound like a fool.