§7 reference plugin (todo §7); plugins/scheduling is the worked example of the plugin contract — a list page fetching upstream data, a CSRF-guarded form forwarding writes upstream, permission-gated nav. shifts.ts: an injectable-fetch upstream REST client (stateless stand-in for the customer backend) + thin handler factories (list filters by ?q + degrades to a recoverable page on upstream-down; create CSRF-guards via ctx.verifyCsrf, validates, forwards, PRG, 502 on upstream 4xx). plugin.ts: apiVersion literal, namespaced scheduling:read/write perms, nav gated so the whole Scheduling header vanishes for non-holders. Views compose the core building blocks around the native app shell, incl. the plugin's own partials/shift-form. New host capability so a plugin page is native + secure (src/chrome.ts buildPluginChrome): ctx.chrome = brand/global-nav/user/theme/csrf for partials/shell (global menu = Dashboard + every plugin nav fragment + gated admin section, role-filtered + current-marked); ctx.verifyCsrf = the host's bound double-submit verifier (secret stays in the host). Both added to RequestContext (defaulted in buildContext), built per plugin route in app.ts (CSRF cookie set when fresh). Dashboard merges plugin nav fragments too (gated => invisible to anonymous, visual E2E byte-identical). Out of the box: bootstrap grants the demo admin scheduling:read/write (seedAdmin generalized to a roles list, env ADMIN_ROLES); dev compose runs a tiny stdlib mock upstream (examples/shifts-upstream, SCHEDULING_UPSTREAM). plugins/ added to tsconfig + the npm test glob. Tests-first across shifts/chrome/app/dashboard/bootstrap. README Building-a-plugin + Layout and docs/plugin-contract.md (ctx.chrome/verifyCsrf, upstream pattern) updated. typecheck + 296 units + the Ory-free visual E2E green (plugin discovered at boot, routes/nav gated, dashboard unchanged); live full-stack boot-verified (stack up with plugin + mock upstream serving the seeded shifts, bootstrap grants in real Keto all allowed:true) then torn down. apiVersion stays 1.0.0 (contract still assembled in §7). Authenticated browser happy-path deferred to §8 full E2E (line 114).

src/context.ts

@@ -1,4 +1,5 @@
 import type { IncomingMessage, ServerResponse } from "node:http";
+import type { PageChrome } from "./chrome.ts"; // type-only: no runtime import, so no cycle
 
 // The request context threaded to every route handler (plugin + built-in), built once
 // per request by `buildContext`: the router supplies matched path `params`, the §4 JWT
@@ -13,6 +14,9 @@ export interface User {
 }
 
 export interface RequestContext {
+  // Page chrome (brand/global-nav/user/theme/csrf) a plugin view hands to partials/shell so its
+  // page renders the native app shell; the host builds it per request (anonymous default otherwise).
+  chrome: PageChrome;
   params: Record<string, string>; // path params from the route match, e.g. /users/:id → { id }
   query: URLSearchParams; // alias of url.searchParams, for ctx.query.get("q")
   req: IncomingMessage;
@@ -20,13 +24,21 @@ export interface RequestContext {
   roles: string[]; // user?.roles ?? [] — coarse gate without a null-check
   url: URL;
   user: User | null;
+  // Gate a first-party form submission: true iff `submitted` matches this request's signed CSRF
+  // cookie (double-submit). The host binds the secret; a plugin calls it after reading its body.
+  verifyCsrf(submitted: string | null | undefined): boolean;
 }
 
 export interface BuildContextOptions {
+  chrome?: PageChrome;
   params?: Record<string, string>;
   user?: User | null;
+  verifyCsrf?: (submitted: string | null | undefined) => boolean;
 }
 
+// Anonymous default chrome — used until the host supplies a real one (built-in routes, tests).
+const ANON_CHROME: PageChrome = { brand: { name: "Plainpages" }, csrfToken: "", nav: [], user: { email: "", initials: "G", name: "Guest" } };
+
 export function buildContext(
   req: IncomingMessage,
   res: ServerResponse,
@@ -35,6 +47,7 @@ export function buildContext(
   const url = new URL(req.url ?? "/", "http://localhost");
   const user = options.user ?? null;
   return {
+    chrome: options.chrome ?? ANON_CHROME,
     params: options.params ?? {},
     query: url.searchParams,
     req,
@@ -42,5 +55,6 @@ export function buildContext(
     roles: user?.roles ?? [],
     url,
     user,
+    verifyCsrf: options.verifyCsrf ?? (() => false), // fail-closed unless the host binds the secret
   };
 }