embabel contract generate --view <name>

Draft an ODCS v3.1 data contract describing what one of your saved views returns.

embabel contract generate --view account_health

That reads the view’s declaration, runs nothing, writes nothing, and prints the contract for you to read. Three further flags each buy one more step, and none of them is on by default:

Flag	What it adds
--sample	runs the view once, under a row cap, to infer column types
--save	writes the draft into the world’s config/contracts
--bind	pins the view to it in observe mode (implies --save)
--output <file>	writes the YAML to a file instead of printing it

The listing marks every column with where its entry came from, because that is the distinction the whole thing turns on:

    ~ account                      string       sampled  suggests required, unique
    ✓ last_seen                    —            declared

✓ declared was read from the view as written and is true of it. ~ sampled was inferred from one run and might not hold tomorrow — which is why an inferred type is written into the contract but an inferred constraint is not. “This column was never null in 500 rows” becomes a suggestion a person confirms, never a promise the appliance starts enforcing.

Nothing this command does can withhold anybody’s rows. A generated contract is draft and a binding it creates is observe, which records verdicts and returns every row. Moving either to active / enforce is an edit you make by hand, once you believe it.

It refuses rather than guesses. A view that returns *, a bare node, or two columns with the same name comes back as a refusal naming what to change — because a contract that is wrong and later enforced is worse than no contract at all.