validate

tune already runs its three safety steps automatically. validate lets you run those same steps on their own, when you want to check something by hand:

Command	When	What it answers
`validate before`	Before tuning	"Is this really the right file for this recipe?"
`validate check`	When `before` fails	"Are the recipe's bytes anywhere in this file at all — shifted, or wrong ECU?"
`validate after`	After tuning	"Were all the changes really written?"

Think of it as the safety checks of tuning, available one at a time. Like every OpenRemap check, validate only reads files — it never changes anything.

When do I need it?

When tune refuses: run validate check to learn why — the answer is either "shifted" (a different software version; the changes may still be recoverable) or "missing" (wrong file — do not force it).
When you tuned a file outside openremap tune and want an independent confirmation.
When you want a saved JSON report of a single check (--json --output report.json) for your records or a script.

Try it (2 minutes)

# 1. Check the file before tuning
openremap validate before target.bin recipe.remap

# 2. Only if step 1 fails — find out why
openremap validate check target.bin recipe.remap

# 3. After tuning — confirm the changes are really there
openremap validate after target_tuned.bin recipe.remap

A passing before prints something like:

  ✅ Safe to tune

  Target               target.bin
  Instructions         277
  Passed               277

(Shortened — see the CLI page for the full outputs, including failures.)

Understanding the answer

Verdict	In plain words
Safe to tune (before)	Every "before" byte is where the recipe expects — safe to apply
NOT safe to tune (before)	Some bytes are missing — stop, run `validate check`
SHIFTED RECOVERABLE (check)	The bytes exist but in a shifted position — a different software version; `tune` may still recover them, with care
MISSING UNRECOVERABLE (check)	The bytes are nowhere in the file — this is the wrong ECU. Do not tune
Tune confirmed (after)	Every change was written correctly — next step is checksum correction before flashing

For developers

Each step is its own method of openremap.api — validate_before, validate_check, validate_after:

Way of using it	Where to look	Example
Terminal (CLI)	validate — CLI	`openremap validate before target.bin recipe.remap`
Python code	validate — API	`api.call("validate_before", {"path": "target.bin", "recipe": recipe})`
Any language (JSON-RPC)	validate — API	a request with `"method": "validate_check"`

Where to go next

You want to…	Go to
Full reference of the three sub-commands	validate — CLI
Call the checks from your own code	validate — API
The one-shot apply that runs these steps for you	`tune`
The receipt check after everything	`audit`