Terraform Plan Lens

Your Terraform plan, on your code.
See what every block will create, update, replace or destroy — refactor without recreating anything,
see your values as you write, and know what an edit does before you plan.

terraform plan prints a wall of text in a terminal, far from the code it is about. You scroll, you search for -/+, you hope you didn't miss the line that replaces the production database. Plan Lens puts the plan where you work: on each block of your code, in a sidebar that shows the risky changes first, and in the hover with every attribute that changes and what forces the replace.

Works with Terraform and OpenTofu, any cloud (AWS, Azure, Google Cloud…), any layout: one folder, environments with their tfvars, Terraform workspaces, monorepos.

Your plan, on your code

Click ▷ next to an environment. Plan Lens runs the plan and every resource, data and module block gets a gutter icon, a coloured band and a hint: replace — forced by hash_key, update · 2 attributes, 3 instances: 1 update · 2 unchanged. The sidebar puts what needs a look first — replaces and destroys, including resources you removed from the code.

• Hover a block: before → after for every attribute, forces replacement, (sensitive), (known after apply).
• The plan card: +1 create ~1 update ±1 replace −1 destroy, and a bar per change, the riskier the taller — the blast radius at a glance.
• Everything else in the plan: imports (an import that is replaced right away is flagged), moved objects, output changes, and what changed outside Terraform — discreet by default.

Refactor without recreating anything

Renamed a resource, moved it into a module, switched count to for_each? Terraform plans a destroy and a create: the object would be recreated. Plan Lens recognises the pairs — same type, same values, new address — and offers the moved blocks. Write & re-plan, and the destroys are gone.

Whole module moves fold into one moved { from = module.old to = module.new }. Pairs it is not sure about are shown but never ticked for you. Nothing touches the state: the blocks go in moved.tf, reviewable in your PR.

Your values, as you write

What does { for s in var.services : s.name => s } actually give for prod? Plan Lens shows what locals, variables, for_each and outputs evaluate to for the selected environment, at the end of the line — and completes map keys and object fields from your real data.

It works in your modules too: a module file shows its values for each call of it (module.subnet["app"], ["db"]…), every instance in the hover.

It is Terraform's own evaluator (terraform console) with the environment's variables, run on Plan Lens's own copy of your configuration with an empty local state: your team's state is never read or locked. Select any expression and run Evaluate selection to see its value.

Know before you plan

Once an environment is planned, saving a file previews just the blocks you edited: a read-only, targeted plan says on the edited lines what that would do — before anyone runs the full plan.

-target on the edited blocks, -refresh=false, -lock=false: seconds, not minutes, never blocks a teammate, never applied.

Always know where you are

Give each environment its own accent — prod in coral, dev in green — and the whole view takes it: the header line, the environment's name, the buttons. Before you hit Apply, you see which environment you are about to change.

Pick them in the settings tab (the gear in the sidebar), with a live preview "as" any environment — or by name or pattern in settings.json: "planLens.style.envAccents": { "PROD": "sunset", "*dev*": "forest" }.

And also

• Environments with no setup — environments/*/terraform.tfvars (+ backend.conf), any folder of tfvars, every Terraform root of a monorepo, Terraform workspaces (local, or listed from the backend).
• Targeting — pick changes or whole modules, plan with -target, see what Terraform pulled in as dependencies.
• Apply the exact plan you reviewed — opt-in per workspace; a destroy or replace asks you to type the environment's name. Terraform refuses it if the state moved since.
• Stuck state lock — shows who holds it and since when, force-unlocks after you confirm.
• Expired cloud login — offers az login, aws sso login or gcloud auth application-default login in a terminal.
• Load a plan file from your CI (terraform show -json, or a binary plan).
• Settings in an editor tab (gear in the sidebar), with a live preview: what each sidebar section shows, every feature on or off, and your look — accent (Aurora, Sunset, Forest, Terraform, Mono or your own colours), an accent per environment, corners, density, motion.

Safe by design

Plan Lens runs Terraform only in trusted workspaces. It sends nothing anywhere: no telemetry, no account.

Get started

1. Install Terraform Plan Lens, open a folder with Terraform code.
2. Open the Plan Lens view in the activity bar.
3. Click ▷ next to an environment (or Run plan). Your usual credentials are used (az login, AWS profile, gcloud…).

No environment layout to adopt: a plain folder with .tf files works. Plan Lens pairs well with HashiCorp's Terraform extension (syntax, completion of the language): they don't overlap.

Settings

All in the settings tab (the gear in the sidebar, or Plan Lens: Settings), or as planLens.* settings.

Colours are theme colours (planLens.create, planLens.replace, …): override them in workbench.colorCustomizations.

FAQ

Does it need my cloud credentials? For plans and previews, the same as terraform plan does. Values and completions don't: they never read the state.

Terraform Cloud / HCP Terraform? Load the plan JSON of a run (Load plan file…). Running plans from Plan Lens needs a backend Terraform can plan against locally.

Where do the GIFs come from? A real VS Code on an ordinary AWS project, applied on LocalStack — every plan you see is Terraform's own. npm run demo records them again.

Development

npm install
npm run test:unit   # model tests
npm run render      # sidebar screenshots in out-render/, fails on overflow
npm run e2e         # VS Code end to end on a real refactored root (needs terraform)
npm run demo        # README GIFs (needs docker and terraform)
npm run package     # tf-plan-lens-<version>.vsix

MIT licensed.