diff --git a/diigo-cache/src/api.ts b/diigo-cache/src/api.ts
index ed360bf..745cd9b 100644
--- a/diigo-cache/src/api.ts
+++ b/diigo-cache/src/api.ts
@@ -14,13 +14,13 @@
  */
 
 import { RpcTarget } from "capnweb";
-import type { DiigoCache, FillStatus, PublicCache } from "./cache.js";
+import type { DiigoCacheLogic, FillStatus, PublicCacheLogic } from "./cache.js";
 import { idFromWebkey, isWebkey, shashKey } from "./webkeys.js";
 
 /** the bindings the API reaches (structural) */
 export type ApiEnv = {
-	CACHE_DO: DurableObjectNamespace<DiigoCache>;
-	PUBLIC_DO: DurableObjectNamespace<PublicCache>;
+	CACHE_DO: DurableObjectNamespace<DiigoCacheLogic>;
+	PUBLIC_DO: DurableObjectNamespace<PublicCacheLogic>;
 };
 
 /** the fill-job surface of one cache (private or public) */
diff --git a/diigo-cache/src/cache.ts b/diigo-cache/src/cache.ts
index e925d10..4d6b5f1 100644
--- a/diigo-cache/src/cache.ts
+++ b/diigo-cache/src/cache.ts
@@ -1,6 +1,9 @@
 /**
- * @file the cache Durable Objects: `DiigoCache` (public+private items) and
- * `PublicCache` (public-only items, widely shared). They are independent
+ * @file the cache Durable Objects' logic: `DiigoCacheLogic` (public+private
+ * items) and `PublicCacheLogic` (public-only items, widely shared). Logic
+ * only: each requires its {@link Clock}; the worker's entry module
+ * (src/index.ts) is the edge that makes the live one and exports the
+ * runtime-constructed `DiigoCache`/`PublicCache`. They are independent
  * and work the same way ({@link PagedCache}): pages are the unit of
  * caching; a hit is answered from `ctx.storage.sqlite` with no diigo call;
  * a miss asks the webapp instance in the cache's wiring and etches the
@@ -117,14 +120,9 @@ abstract class PagedCache extends DurableObject<CacheEnv> {
 	#pause?: Promise<void>;
 	#clock: Clock;
 
-	/** the runtime constructs DOs with (ctx, env), so the default — the
-	 * live clock, made here at the edge, nowhere in module scope — applies;
-	 * a subclass (tests) can pass another */
-	constructor(
-		ctx: DurableObjectState,
-		env: CacheEnv,
-		clock: Clock = { now: () => Date.now(), sleep: (ms) => new Promise((r) => setTimeout(r, ms)) },
-	) {
+	/** `clock` is required: time comes from the edge that constructs us
+	 * (src/index.ts in the worker, tests/test-worker.ts in tests) */
+	constructor(ctx: DurableObjectState, env: CacheEnv, clock: Clock) {
 		super(ctx, env);
 		this.#clock = clock;
 	}
@@ -338,10 +336,11 @@ abstract class PagedCache extends DurableObject<CacheEnv> {
 }
 
 /**
- * the private cache (export name `DiigoCache`): public+private items,
- * addressed by its cache id (a webkey, held by the user).
+ * the private cache's logic (exported to the runtime as `DiigoCache` by
+ * src/index.ts): public+private items, addressed by its cache id (a
+ * webkey, held by the user).
  */
-export class DiigoCache extends PagedCache {
+export class DiigoCacheLogic extends PagedCache {
 	protected readonly kind = "private";
 
 	protected keep(rows: ItemRow[]): ItemRow[] {
@@ -375,7 +374,7 @@ export class DiigoCache extends PagedCache {
  * (the idFromName("index") instance holds the kv mapping and is never
  * wired).
  */
-export class PublicCache extends PagedCache {
+export class PublicCacheLogic extends PagedCache {
 	protected readonly kind = "public";
 
 	protected keep(rows: ItemRow[]): ItemRow[] {
diff --git a/diigo-cache/src/index.ts b/diigo-cache/src/index.ts
index 2b13d11..d1979fa 100644
--- a/diigo-cache/src/index.ts
+++ b/diigo-cache/src/index.ts
@@ -17,16 +17,39 @@ import { newWorkersRpcResponse } from "capnweb";
 import { CacheApi } from "./api.js";
 import { CAPNWEB_BROWSER_JS } from "./capnweb-browser.js";
 import { CACHE_PAGE_HTML } from "./cache-page.js";
-import { DiigoCache, PublicCache } from "./cache.js";
-import type { FillStatus } from "./cache.js";
+import { DiigoCacheLogic, PublicCacheLogic } from "./cache.js";
+import type { CacheEnv, Clock, FillStatus } from "./cache.js";
 import type { Item } from "./cache.js";
 import { updatedISO, usernameOf } from "./items.js";
 import { toWebkey, idFromWebkey, isWebkey, shashKey } from "./webkeys.js";
 import { pmSave } from "./pm-save.js";
 
-// the DO classes must be entrypoint exports (the exports/ binding targets
-// the main module)
-export { DiigoCache, PublicCache };
+/**
+ * the live clock. This module is the worker's edge — the runtime's entry,
+ * like a program script — so ambient time is reached here and delegated
+ * down; the cache logic only uses the clock it is given.
+ */
+function liveClock(): Clock {
+	return { now: () => Date.now(), sleep: (ms) => new Promise((r) => setTimeout(r, ms)) };
+}
+
+// The DO classes must be exports of the main module, and the runtime
+// constructs them with (ctx, env) only: a Cloudflare API constraint, met
+// here at the edge by subclasses that supply the live clock.
+
+/** the private cache, as the runtime constructs it */
+export class DiigoCache extends DiigoCacheLogic {
+	constructor(ctx: DurableObjectState, env: CacheEnv) {
+		super(ctx, env, liveClock());
+	}
+}
+
+/** the public cache, as the runtime constructs it */
+export class PublicCache extends PublicCacheLogic {
+	constructor(ctx: DurableObjectState, env: CacheEnv) {
+		super(ctx, env, liveClock());
+	}
+}
 
 /** worker bindings (structural until wrangler types regenerates) */
 type Env = {
diff --git a/diigo-cache/tests/caches.test.ts b/diigo-cache/tests/caches.test.ts
index c26ae79..2c949e7 100644
--- a/diigo-cache/tests/caches.test.ts
+++ b/diigo-cache/tests/caches.test.ts
@@ -9,8 +9,8 @@ import { FETCH_BUDGET } from "../src/query.js";
 const WEBAPP_ID = "fake-webapp-id";
 
 type TestEnv = {
-	CACHE_DO: DurableObjectNamespace<import("../src/cache.js").DiigoCache>;
-	PUBLIC_DO: DurableObjectNamespace<import("../src/cache.js").PublicCache>;
+	CACHE_DO: DurableObjectNamespace<import("../src/index.js").DiigoCache>;
+	PUBLIC_DO: DurableObjectNamespace<import("../src/index.js").PublicCache>;
 	WEBAPP: { calls(): Promise<number> };
 };
 const testEnv = env as unknown as TestEnv;
diff --git a/diigo-cache/tests/fill.test.ts b/diigo-cache/tests/fill.test.ts
index d151a69..21e9e67 100644
--- a/diigo-cache/tests/fill.test.ts
+++ b/diigo-cache/tests/fill.test.ts
@@ -12,9 +12,9 @@ import { FIXED_NOW } from "./test-worker.js";
 // of 24, every 3rd private).
 
 type TestEnv = {
-	CACHE_DO: DurableObjectNamespace<import("../src/cache.js").DiigoCache>;
+	CACHE_DO: DurableObjectNamespace<import("../src/index.js").DiigoCache>;
 	CLOCKED_DO: DurableObjectNamespace<import("./test-worker.js").FixedClockCache>;
-	PUBLIC_DO: DurableObjectNamespace<import("../src/cache.js").PublicCache>;
+	PUBLIC_DO: DurableObjectNamespace<import("../src/index.js").PublicCache>;
 	WEBAPP: { calls(): Promise<number> };
 };
 const testEnv = env as unknown as TestEnv;
diff --git a/diigo-cache/tests/test-worker.ts b/diigo-cache/tests/test-worker.ts
index 2caba86..eb68698 100644
--- a/diigo-cache/tests/test-worker.ts
+++ b/diigo-cache/tests/test-worker.ts
@@ -1,9 +1,9 @@
 /**
- * @file the tests' main module: the real worker, plus a DiigoCache on a
- * fixed clock (bound as CLOCKED_DO in wrangler.tests.jsonc), so tests can
- * interpose time through the constructor.
+ * @file the tests' main module — their edge: the real worker (whose own
+ * edge supplies the live clock), plus the private cache's logic on a fixed
+ * clock (bound as CLOCKED_DO in wrangler.tests.jsonc).
  */
-import { DiigoCache } from "../src/cache.js";
+import { DiigoCacheLogic } from "../src/cache.js";
 import type { CacheEnv } from "../src/cache.js";
 
 export * from "../src/index.js";
@@ -12,7 +12,7 @@ export { default } from "../src/index.js";
 /** 2026-10-07T12:00:00Z */
 export const FIXED_NOW = Date.UTC(2026, 9, 7, 12, 0, 0);
 
-export class FixedClockCache extends DiigoCache {
+export class FixedClockCache extends DiigoCacheLogic {
 	constructor(ctx: DurableObjectState, env: CacheEnv) {
 		super(ctx, env, { now: () => FIXED_NOW, sleep: async () => {} });
 	}