# Glossary

- **Content addressing** — an app's identity *is* the hash of its bytes; the hash and output are bound immutably.
- **Resolver** — an on-chain `view` contract supplying live data/media to a UI at render time.
- **Trust grade** — A/B/C letter (+ itemized breakdown) disclosing how trustless an app is.
- **Enforcer** — the on-chain gate that refuses unsafe apps and grades the rest (rails R1–R7).
- **Capability envelope** — the union of everything an app can do; declared, then verified.
- **Construct-for-sign** — building an action's calldata from its declaration, so it can only be what's declared.
- **Presentation context** — render-time theme/palette/dimensions; changes appearance without changing the hash.
- **Design tokens** — semantic style values (spacing/color/typography) themes are built from; W3C-aligned.
- **Poster floor** — the on-chain fallback image a media/GPU resolver degrades to; keeps apps grade A.
- **Fail-closed** — on any error, degrade to an honest fallback, never a fabrication.
- **Drift-lock** — a test guaranteeing the SDK and on-chain logic compute identical results.
- **Subname registry** — names under `chainrender.eth`; the registrar is truth, ENS is a projection.
- **Versioned name** — a name → current version, with append-only history + timelock (safe updates).