diff --git a/.project/concepts/app-contract/contract_polyfill-surface.md b/.project/concepts/app-contract/contract_polyfill-surface.md
index 8a862fe..4342722 100644
--- a/.project/concepts/app-contract/contract_polyfill-surface.md
+++ b/.project/concepts/app-contract/contract_polyfill-surface.md
@@ -16,7 +16,8 @@ This package covers placement (creating and listing an application's documents b
 An application using this package must:
 
 - serve a wallet file (`.ngw`) from its own bundle, and pass its URL and password to `configure` as `sharedWallet: { fileUrl, password }`;
-- call `ensureIdentity()` in a browser context before rendering its interface; it mounts a barrier in the document.
+- call `init(…)` — this package's, not the one it passed to `configure` — and then await `ensureIdentity()`, in a browser context, before rendering its interface. `ensureIdentity()` resolves once a session is open, so awaiting it before `init` has been called never resolves;
+- expect `ensureIdentity()` to mount a full-screen barrier on every top-level load, and the page to reload itself once when a person returns to it: hold no un-persisted state across that call.
 
 ## Surface