diff --git a/vinci/test/402-escalation-no-downgrade.mjs b/vinci/test/402-escalation-no-downgrade.mjs
index 25e227be0..e5d2aa8e8 100644
--- a/vinci/test/402-escalation-no-downgrade.mjs
+++ b/vinci/test/402-escalation-no-downgrade.mjs
@@ -1,37 +1,180 @@
 import assert from "node:assert/strict";
 import { dirname, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
+import {
+	createAssistantMessageEventStream,
+	fauxAssistantMessage,
+	registerApiProvider,
+	unregisterApiProviders,
+} from "@earendil-works/pi-ai/compat";
 import { createJiti } from "jiti/static";
 
 const here = dirname(fileURLToPath(import.meta.url));
 const loader = createJiti(import.meta.url, { moduleCache: false, tryNative: false });
-const provenance = await loader.import(resolve(here, "../extensions/vinci-model-provenance.ts"), { default: false });
+const advisorExtension = await loader.import(resolve(here, "../extensions/vinci-advisor.ts"), { default: false });
+const { runCouncil } = await loader.import(resolve(here, "../extensions/vinci-council.ts"), { default: false });
+const { judgeScope } = await loader.import(resolve(here, "../extensions/vinci-scope.ts"), { default: false });
+const { getUnstuck } = await loader.import(resolve(here, "../extensions/vinci-loopbreak.ts"), { default: false });
 
-const { classifyVinciModelError } = provenance;
+const BILLING_ERRORS = [
+	["in-flight", "in_flight_budget_exhausted"],
+	["affordability", "You requested up to 131072 tokens, but can only afford 23014"],
+];
 
-const IN_FLIGHT_402 = Object.assign(new Error("in_flight_budget_exhausted"), { status: 402 });
-const AFFORDABILITY_402 = Object.assign(new Error("You requested up to 131072 tokens, but can only afford 23014"), { status: 402 });
+function model(api, id) {
+	return {
+		id,
+		name: `Vinci ${id}`,
+		api,
+		provider: "vinci",
+		baseUrl: "http://localhost:0",
+		reasoning: false,
+		input: ["text"],
+		cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+		contextWindow: 128000,
+		maxTokens: 16384,
+	};
+}
 
-// ASSERTION 1 & 2: Classifier must return "account" for marked 402s
-const inFlightKind = classifyVinciModelError(IN_FLIGHT_402);
-assert.equal(inFlightKind, "account", "in-flight 402 must classify as account");
+function successStream(text, requestModel) {
+	const stream = createAssistantMessageEventStream();
+	const message = {
+		...fauxAssistantMessage(text),
+		api: requestModel.api,
+		provider: requestModel.provider,
+		model: requestModel.id,
+	};
+	queueMicrotask(() => stream.push({ type: "done", reason: "stop", message }));
+	return stream;
+}
 
-const affordabilityKind = classifyVinciModelError(AFFORDABILITY_402);
-assert.equal(affordabilityKind, "account", "affordability 402 must classify as account");
+async function assert402StopsEscalation(site, body, run, leadingResponses = []) {
+	const api = `test:402-${site}`;
+	const sourceId = `402-escalation-${site}`;
+	const calls = [];
+	const notices = [];
+	const terminalError = Object.assign(new Error(body), { status: 402 });
+	const steps = [
+		...leadingResponses,
+		{ error: terminalError },
+		{ error: Object.assign(new Error(body), { status: 402 }) },
+		{ text: "CHEAPER FALLBACK MUST NOT RUN" },
+	];
+	const models = {
+		forte: model(api, "forte"),
+		fortissimo: model(api, "fortissimo"),
+	};
+	const stream = (requestModel) => {
+		calls.push(requestModel.id);
+		const step = steps.shift();
+		assert.ok(step, `${site}: no unplanned model call may occur`);
+		if (step.error) throw step.error;
+		return successStream(step.text, requestModel);
+	};
+	registerApiProvider({ api, stream, streamSimple: stream }, sourceId);
 
-// ASSERTION 3: Escalation site logic - no downgrade on marked 402
-const unavailableClasses = [];
-const kind = inFlightKind;
-const attempt = 0;
-const SAME_CLASS_ATTEMPTS = 2;
+	const registry = {
+		find(provider, id) {
+			return provider === "vinci" ? models[id] : undefined;
+		},
+		async getApiKeyAndHeaders() {
+			return { ok: true, apiKey: "test-key" };
+		},
+	};
+	const ctx = {
+		cwd: process.cwd(),
+		hasUI: true,
+		model: models.forte,
+		modelRegistry: registry,
+		sessionManager: { getSessionId: () => `402-${site}` },
+		ui: { notify: (message, level) => notices.push({ message, level }) },
+	};
+	usageSessionStart({}, ctx);
 
-if (kind === "transient" && attempt < SAME_CLASS_ATTEMPTS) {
-  throw new Error("DEFECT: would retry same class");
+	try {
+		await assert.rejects(
+			() => run({ ctx, models, registry, announce: (message, level) => notices.push({ message, level }) }),
+			(error) => {
+				assert.match(error.message, /will not downgrade after an account or terminal error/i);
+				assert.equal(error.cause?.status, 402, `${site}: the terminal error must retain the real HTTP status`);
+				assert.strictEqual(error.cause, terminalError, `${site}: the terminal wrapper must preserve the provider error`);
+				return true;
+			},
+			`${site}: a 402 must throw instead of returning a cheaper-class result`,
+		);
+		assert.deepEqual(
+			calls,
+			[...leadingResponses.map(() => "forte"), "fortissimo"],
+			`${site}: no retry or cheaper class may be attempted after a 402`,
+		);
+		assert.equal(steps.length, 2, `${site}: the same-class retry and cheaper fallback must remain unused`);
+		assert.equal(
+			notices.some(({ level, message }) => level === "warning" || /unavailable|continuing with/i.test(message)),
+			false,
+			`${site}: a 402 must not enter the unavailable-class downgrade path`,
+		);
+	} finally {
+		unregisterApiProviders(sourceId);
+	}
 }
-if (kind === "transient" || kind === "unavailable") {
-  unavailableClasses.push("cheaper");
-  throw new Error("DEFECT: would downgrade");
+
+let advisorTool;
+let usageSessionStart;
+advisorExtension.default({
+	appendEntry() {},
+	on(event, handler) {
+		if (event === "session_start") usageSessionStart = handler;
+	},
+	registerTool(tool) {
+		if (tool.name === "advisor") advisorTool = tool;
+	},
+});
+assert.ok(advisorTool, "advisor tool must register");
+assert.ok(usageSessionStart, "usage accumulator must bind to the active test task");
+
+const consumers = [
+	[
+		"advisor",
+		({ ctx }) => advisorTool.execute("402-advisor", { question: "Review this" }, undefined, undefined, ctx),
+		[],
+	],
+	[
+		"council",
+		({ ctx, registry, announce }) =>
+			runCouncil(
+				ctx.model,
+				{ apiKey: "test-key" },
+				"Choose an approach",
+				registry,
+				ctx.sessionManager.getSessionId(),
+				announce,
+			),
+		[
+			{ text: "optimist take" },
+			{ text: "skeptic take" },
+			{ text: "realist take" },
+			{ text: "strategist take" },
+		],
+	],
+	["scope", ({ ctx }) => judgeScope(ctx, "unrelated.ts"), []],
+	["loopbreak", ({ ctx }) => getUnstuck(ctx, "bash repeated", [], "Fix the loop"), []],
+];
+
+const requestedConsumer = process.env.VINCI_TEST_402_CONSUMER?.trim();
+const selectedConsumers = requestedConsumer
+	? consumers.filter(([site]) => site === requestedConsumer)
+	: consumers;
+assert.ok(
+	selectedConsumers.length > 0,
+	`VINCI_TEST_402_CONSUMER must name one of: ${consumers.map(([site]) => site).join(", ")}`,
+);
+
+for (const [variant, body] of BILLING_ERRORS) {
+	for (const [site, run, leadingResponses] of selectedConsumers) {
+		await assert402StopsEscalation(`${site}-${variant}`, body, run, leadingResponses);
+	}
 }
-assert.deepEqual(unavailableClasses, [], "no downgrade attempted");
 
-console.log("402-escalation-no-downgrade: all assertions passed");
+const consumerSummary = requestedConsumer ?? "all four consumers";
+const consumerVerb = requestedConsumer ? "rejects" : "reject";
+console.log(`402-escalation-no-downgrade: ${consumerSummary} ${consumerVerb} both 402 variants without downgrade`);
diff --git a/vinci/test/run.sh b/vinci/test/run.sh
index 0be60aa8f..a78a554a4 100644
--- a/vinci/test/run.sh
+++ b/vinci/test/run.sh
@@ -273,6 +273,7 @@ run_group ask-checklist-integration node "${ROOT}/vinci/test/ask-checklist-integ
 run_group issue-integration node "${ROOT}/vinci/test/issue-integration.mjs"
 run_group billing-codes-integration node "${ROOT}/vinci/test/billing-codes-integration.mjs"
 run_group 402-classification-integration node "${ROOT}/vinci/test/402-classification-integration.mjs"
+run_group 402-escalation-no-downgrade node "${ROOT}/vinci/test/402-escalation-no-downgrade.mjs"
 run_group no-downgrade-integration node "${ROOT}/vinci/test/no-downgrade-integration.mjs"
 run_group units node "${ROOT}/vinci/test/units.mjs"
 # Worker daemon: every vinci/test/worker-*.mjs runs, discovered by glob so a new file cannot be