@@ -1,4 +1,5 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+// test-budget: 20 — spawns the real producer once per single-cause fixture: twenty-four in-process kernel boots, one per describe (each shape × registration, package state and artifact fixture), each answering its block's bridge and door reads; slowest CI reading 14.93 s (run 40200279306, refresh PR #25960's window (hourly runs 40200279306 to 40272142430)) x 1.25, rounded up; read before this file paid each shape's first boot at module scope
 
 /**
  * [#25120] The `/mcp` bridge sees the objects a PACKAGE contributes: listed,
@@ -275,6 +276,13 @@ const REGISTRATIONS = [
     { label: 'installed after the boot, as marketplace install registers it', when: 'install' },
 ] as const;
 
+// [#23181] Pay each shape's first boot at module scope, never in a hook: vitest
+// clocks a hook as it clocks a test, and each shape's first boot was the slow
+// one (276 and 163 ms against 45 to 131 ms for the rest, isolated). The throwaway kernel is
+// the first describe's own fixture, booted and shut down before any hook runs,
+// so it leaves nothing behind that a later boot does not already inherit.
+for (const { environmentId } of SHAPES) await shutdown(await bootKernel(environmentId, 'boot', packageOf('qa_pkg')));
+
 for (const { shape, environmentId } of SHAPES) {
     for (const { label, when } of REGISTRATIONS) {
         describe(`[#25120] the /mcp bridge and a package's objects — ${shape}, ${label}`, () => {
 
@@ -484,6 +484,24 @@ function bootRest(callerName: CallerName, opts: Boot = {}) {
     return { read, protocol };
 }
 
+/**
+ * [#23181] The census blocks (row A, the item read, the layered route, the book
+ * tree) read every cell through ONE booted pair per caller, booted on its first
+ * cell and reused after. They booted a fresh pair per caller per cell, about
+ * 3,100 boots, and `bootRest`'s `registerRoutes()` was half the file's time.
+ * Reuse changes no answer: neither transport keeps one between two GET reads
+ * (`RestServer`'s per-request memo is keyed on the request object, and the
+ * dispatcher's membership cache on an environment no read here names), and
+ * every protocol-double read clones its fixture. The blocks that assert on a
+ * double's calls, or boot with options, still boot their own.
+ */
+const censusPairs = new Map<CallerName, { dispatcher: ReturnType<typeof bootDispatcher>; rest: ReturnType<typeof bootRest> }>();
+function censusPair(who: CallerName) {
+    let pair = censusPairs.get(who);
+    if (!pair) censusPairs.set(who, (pair = { dispatcher: bootDispatcher(who), rest: bootRest(who) }));
+    return pair;
+}
+
 const text = (a: Answer): string => JSON.stringify(a.body ?? null);
 const names = (items: any[] | undefined): string[] => (items ?? []).map((i: any) => i?.name);
 const brief = (a: Answer) => ({
@@ -636,8 +654,8 @@ describe('[#20320] row A: the dispatcher lists what RestServer lists — every t
             it(`GET /meta/${type} ${probe.label}`, async () => {
                 const mismatches: unknown[] = [];
                 for (const who of LIST_CALLERS) {
-                    const dispatcher = await bootDispatcher(who).read(`/meta/${type}`, probe.query, probe.headers);
-                    const rest = await bootRest(who).read(`/meta/${type}`, probe.query, probe.headers);
+                    const dispatcher = await censusPair(who).dispatcher.read(`/meta/${type}`, probe.query, probe.headers);
+                    const rest = await censusPair(who).rest.read(`/meta/${type}`, probe.query, probe.headers);
                     const same = dispatcher.status === rest.status
                         && dispatcher.code === rest.code
                         && JSON.stringify(dispatcher.items) === JSON.stringify(rest.items)
@@ -996,8 +1014,8 @@ describe('[#20408] the item read: the dispatcher answers what RestServer answers
             it(`GET ${path} ${probe.label}`, async () => {
                 const mismatches: unknown[] = [];
                 for (const who of ITEM_CALLERS) {
-                    const dispatcher = await bootDispatcher(who).read(path, probe.query, probe.headers);
-                    const rest = await bootRest(who).read(path, probe.query, probe.headers);
+                    const dispatcher = await censusPair(who).dispatcher.read(path, probe.query, probe.headers);
+                    const rest = await censusPair(who).rest.read(path, probe.query, probe.headers);
                     if (!sameAnswer(dispatcher, rest)) mismatches.push(mismatchOf(who, dispatcher, rest));
                 }
                 expect(mismatches).toEqual([]);
@@ -1059,8 +1077,8 @@ describe('[#20478] GET /meta/:type/:name/layers: the dispatcher serves the route
             it(`GET ${path}/layers ${probe.label}`, async () => {
                 const mismatches: unknown[] = [];
                 for (const who of ITEM_CALLERS) {
-                    const dispatcher = await bootDispatcher(who).read(`${path}/layers`, probe.query, probe.headers);
-                    const rest = await bootRest(who).read(`${path}/layers`, probe.query, probe.headers);
+                    const dispatcher = await censusPair(who).dispatcher.read(`${path}/layers`, probe.query, probe.headers);
+                    const rest = await censusPair(who).rest.read(`${path}/layers`, probe.query, probe.headers);
                     if (!sameAnswer(dispatcher, rest)) mismatches.push(mismatchOf(who, dispatcher, rest));
                 }
                 expect(mismatches).toEqual([]);
@@ -1226,8 +1244,8 @@ describe('[#20408] GET /meta/book/:name/tree: the dispatcher serves the route Re
             it(`GET /meta/book/${book}/tree ${probe.label}`, async () => {
                 const mismatches: unknown[] = [];
                 for (const who of TREE_CALLERS) {
-                    const dispatcher = await bootDispatcher(who).read(`/meta/book/${book}/tree`, probe.query, probe.headers);
-                    const rest = await bootRest(who).read(`/meta/book/${book}/tree`, probe.query, probe.headers);
+                    const dispatcher = await censusPair(who).dispatcher.read(`/meta/book/${book}/tree`, probe.query, probe.headers);
+                    const rest = await censusPair(who).rest.read(`/meta/book/${book}/tree`, probe.query, probe.headers);
                     if (!sameAnswer(dispatcher, rest)) mismatches.push(mismatchOf(who, dispatcher, rest));
                 }
                 expect(mismatches).toEqual([]);
 
@@ -1,4 +1,5 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+// test-budget: 30 — spawns the real producer once per single-cause fixture: one in-process boot of the real stack, then a sandboxed body or host handler run through the real doors per reader context, verb and caller; slowest CI reading 16.31 s (run 40200279306, refresh PR #25960's window (hourly runs 40200279306 to 40272142430)) x 1.25, rounded up; the first loads already paid at module scope
 
 /**
  * The in-process reader contexts over the stored-metadata-body family
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,5 @@`
`1`	`1`	`// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.`
	`2`	`+// test-budget: 30 — spawns the real producer once per single-cause fixture: one in-process boot of the real stack, then a sandboxed body or host handler run through the real doors per reader context, verb and caller; slowest CI reading 16.31 s (run 40200279306, refresh PR #25960's window (hourly runs 40200279306 to 40272142430)) x 1.25, rounded up; the first loads already paid at module scope`
`2`	`3`
`3`	`4`	`/**`
`4`	`5`	`* The in-process reader contexts over the stored-metadata-body family`