11ai TypeScript v7 type modeling

Types describe trusted knowledge; they do not validate untrusted runtime data Resolve the exact module, public contract, target configured JavaScript runtimes and package consumers, and acceptance check before editing.

Version baseline: Target TypeScript 7.0 and its native compiler. It carries TypeScript 6 semantics and defaults, but 7.0 has no programmatic compiler API; retain TypeScript 6 side-by-side when tooling requires that API.

Inspect first

rg -n 'interface |type | as |unknown|any|satisfies|readonly|Record<' TARGET
npx tsc --noEmit

Locate the runtime source of each value, existing validators, mutation ownership, and all exported consumers before reshaping a type.

Confirm before changing:

• Discriminants for state variants.
• Unknown at untrusted boundaries.
• Readonly where mutation is not owned.
• Runtime validation separate from typing.

Operate

npx tsc --noEmit
npm test --if-present -- TARGET

Model valid states directly, narrow unknown values with runtime evidence, and use satisfies to check without widening.

Never use any, double assertions, non-null assertions, or optional fields to conceal missing runtime guarantees Require approval for a broader or destructive change and preview affected files, exports, callers, or runtime behavior.

Verify and report

npx tsc --noEmit
npm test --if-present
npm run build --if-present

Typecheck callers and test boundary validation for valid, invalid, missing, and future variant inputs. Report target, files, public behavior, compatibility or security impact, checks, and rollback. Hand configuration failures to 11ai-operator-typescript-v7-troubleshooting and seams to 11ai-operator-typescript-v7-integrations.