diff --git a/test/integration/mesh.test.ts b/test/integration/mesh.test.ts
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+++ b/test/integration/mesh.test.ts
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+/**
+ * A mesh, raised from nothing, joined by two machines, delivering a credential neither the mesh
+ * nor the broker can read.
+ *
+ * Everything before this proves a part. This proves the parts meet — which is the thing the
+ * project keeps saying cannot be checked any other way (novox/hq ADR 0001: every fault of
+ * 2026-08-22 was found in production because nothing could be stood up locally).
+ *
+ * It needs a host binary and the substrate bundle:
+ *
+ *   MESH_LAB_HOST_BINARY=.../mesh-host
+ *   MESH_LAB_BUNDLE=.../examples/substrate-first-node.lock
+ *
+ * The bundle's image references are rewritten to the ones this scenario's own registry serves.
+ * A digest belongs to whatever registry serves it, so a committed bundle names a registry that is
+ * not this one — rewriting is what makes it applicable rather than a placeholder to tidy away.
+ */
+
+import { test, before, after } from "node:test";
+import assert from "node:assert/strict";
+import { existsSync, readFileSync } from "node:fs";
+import { loadScenario } from "../../src/declaration/parse.ts";
+import { raise } from "../../src/lifecycle/raise.ts";
+import { destroy, exec } from "../../src/lifecycle/operate.ts";
+import { hostBinaryPath, HOST_PATH } from "../../src/lifecycle/place.ts";
+import { labIsUsable, destroyAll } from "./harness.ts";
+
+const capability = await labIsUsable();
+const binary = hostBinaryPath();
+const bundle = process.env["MESH_LAB_BUNDLE"] ?? "";
+
+const skip = !capability.usable
+  ? `lab not usable: ${capability.why}`
+  : !binary || !existsSync(binary)
+    ? "MESH_LAB_HOST_BINARY is not set to a built mesh-host"
+    : !bundle || !existsSync(bundle)
+      ? "MESH_LAB_BUNDLE is not set to a substrate bundle (mesh-host examples/)"
+      : false;
+
+const SCENARIO = "two-nodes";
+let instanceId = "";
+
+function quote(s: string): string {
+  return `'${s.replaceAll("'", `'\\''`)}'`;
+}
+
+async function on(machine: string, command: string): Promise<{ out: string; ok: boolean }> {
+  const { stdout } = await exec(instanceId, machine, [
+    "sh", "-c", `${command} 2>&1; echo "__exit=$?"`,
+  ]);
+  const marker = stdout.lastIndexOf("__exit=");
+  return { out: stdout.slice(0, marker), ok: Number(stdout.slice(marker + 7).trim()) === 0 };
+}
+
+async function must(machine: string, command: string): Promise<string> {
+  const { out, ok } = await on(machine, command);
+  if (!ok) throw new Error(`${machine}: ${command}\n${out}`);
+  return out;
+}
+
+/** The control plane, which runs in a container on the first node. */
+async function mesh(command: string): Promise<string> {
+  return must("anchor", `docker exec mesh-control /mesh-control ${command}`);
+}
+
+/**
+ * The bundle, with every image reference pointed at this scenario's registry.
+ *
+ * Matched by repository rather than by the whole reference, because the address and the digest
+ * both differ from whatever the committed bundle names — and a bundle that names the wrong
+ * registry is not wrong, it is built for a different target.
+ */
+function bundleFor(images: string[]): string {
+  let text = readFileSync(bundle, "utf8");
+  for (const pinned of images) {
+    const repository = pinned.slice(pinned.indexOf("/") + 1, pinned.indexOf("@"));
+    const escaped = repository.replaceAll("/", "\\/").replaceAll(".", "\\.");
+    text = text.replaceAll(
+      new RegExp(`[A-Za-z0-9_.:-]+\\/${escaped}@sha256:[0-9a-f]+`, "g"),
+      pinned,
+    );
+  }
+  return text;
+}
+
+/** Take a token out of what `token issue` printed. It is the one base64url blob on its own line. */
+function tokenFrom(said: string): string {
+  const found = said.split("\n").map((l) => l.trim()).find((l) => l.length > 100 && !l.includes(" "));
+  assert.ok(found, `no token in:\n${said}`);
+  return found;
+}
+
+before(async () => {
+  if (skip) return;
+  const raised = await raise(loadScenario(`scenarios/${SCENARIO}.yml`), {});
+  instanceId = raised.instanceId;
+
+  // The first node raises everything from a file rather than from a bundle built into the binary,
+  // because the digests are this registry's and are not known until it is up.
+  await must("anchor", `cat > /tmp/substrate.lock <<'MESHBUNDLE'\n${bundleFor(raised.images)}\nMESHBUNDLE`);
+  await must("anchor", `${HOST_PATH} apply /tmp/substrate.lock`);
+}, { timeout: 1_800_000 });
+
+after(async () => {
+  if (instanceId) await destroy(instanceId);
+  await destroyAll(`${SCENARIO}-`);
+}, { timeout: 600_000 });
+
+test("a bare machine becomes a mesh", { skip, timeout: 600_000 }, async () => {
+  const running = await must("anchor", `docker ps --format '{{.Names}}'`);
+  for (const container of ["mesh-store", "mesh-broker", "mesh-control"]) {
+    assert.match(running, new RegExp(container), `${container} is not running`);
+  }
+  // Answering, not merely up. A container that is running is not a control plane that replies —
+  // a distinction this project has already paid for once.
+  assert.ok((await mesh("status")).length > 0);
+});
+
+test("both machines join it, and the token is all they need", { skip, timeout: 900_000 }, async () => {
+  for (const [machine, node] of [["anchor", "anchor"], ["laptop", "laptop"]] as const) {
+    await mesh(`node add ${node}`);
+    const token = tokenFrom(await mesh(`token issue --node ${node}`));
+    // No --name. The token says what the mesh calls the machine, which is the fault this walk
+    // found the first time it was run.
+    const said = await must(machine, `${HOST_PATH} enrol --token ${quote(token)}`);
+    assert.match(said, new RegExp(`enrolled as ${node}`), said);
+    assert.match(said, /sealing key/, "no sealing key was generated");
+  }
+
+  const recorded = await must("anchor",
+    `docker exec mesh-store psql -U postgres -d inventory -qAt ` +
+      `-c "select name from node where sealing_key is not null order by name"`);
+  assert.equal(recorded.trim().split("\n").map((l) => l.trim()).sort().join(","), "anchor,laptop",
+    "the mesh did not record a sealing key for both machines");
+});
+
+test("a credential reaches both ends and the mesh holds neither", { skip, timeout: 900_000 }, async () => {
+  // The whole argument, on real machines: the two ends must hold the SAME password, and it must
+  // appear nowhere the mesh or the broker could read it.
+  await must("anchor", `printf %s '{"module":"postgres","version":"1",` +
+    `"provides":[{"name":"database","scope":"mesh"}],"serves":{"database":{"port":5432}},` +
+    `"grants":{"database":"/var/lib/mesh-host/grants"},` +
+    `"receives":{"database":"/var/lib/mesh-host/grants/mesh.json"},"resources":[]}' > /tmp/pg.json`);
+  await must("anchor", `printf %s '{"module":"meshboard","version":"1",` +
+    `"requires":["database"],"contributes":{"database":{"name":"meshboard"}},` +
+    `"binds":{"database":"/etc/meshboard/database.json"},` +
+    `"secrets":{"database":"/etc/meshboard/database.password"},"resources":[]}' > /tmp/app.json`);
+  await must("anchor", `docker cp /tmp/pg.json mesh-control:/pg.json`);
+  await must("anchor", `docker cp /tmp/app.json mesh-control:/app.json`);
+  await mesh("module add /pg.json");
+  await mesh("module add /app.json");
+
+  await mesh("overlay place anchor --hub --endpoint 192.0.2.10:51820 --site lab");
+  await mesh("overlay place laptop --site lab");
+  for (const node of ["anchor", "laptop"]) await mesh(`assign ${node} networking`);
+  await mesh("assign anchor postgres");
+  await mesh("assign laptop meshboard");
+
+  for (const machine of ["anchor", "laptop"]) {
+    await must(machine, `nohup ${HOST_PATH} run > /var/log/mesh-host.log 2>&1 & sleep 3`);
+  }
+  await mesh("push");
+  await new Promise((r) => setTimeout(r, 8000));
+
+  const onConsumer = (await must("laptop", `cat /etc/meshboard/database.password`)).trim();
+  const onProvider = (await must("anchor", `cat /var/lib/mesh-host/grants/laptop.secret`)).trim();
+  assert.ok(onConsumer.length >= 40, `the consumer's credential is ${onConsumer.length} characters`);
+  assert.equal(onConsumer, onProvider,
+    "the two ends hold different passwords, so nothing could ever authenticate");
+
+  // Only the machine it is for may read it.
+  assert.match(await must("laptop", `stat -c %a /etc/meshboard/database.password`), /^600/);
+
+  // And it is nowhere it could have been read on the way. The declaration crossed the broker; the
+  // database is the control plane's; the state is what the node reported back.
+  for (const [machine, where] of [
+    ["laptop", "/var/lib/mesh-host/declared.json"],
+    ["laptop", "/var/lib/mesh-host/state.json"],
+    ["anchor", "/var/lib/mesh-host/declared.json"],
+  ] as const) {
+    const { out } = await on(machine, `grep -c ${quote(onConsumer)} ${where}`);
+    assert.equal(out.trim(), "0", `the password is in ${where} on ${machine}`);
+  }
+  const inTheMesh = await must("anchor",
+    `docker exec mesh-store psql -U postgres -d inventory -qAt ` +
+      `-c "select count(*) from secret where for_consumer like '%${onConsumer}%' ` +
+      `or for_provider like '%${onConsumer}%'"`);
+  assert.equal(inTheMesh.trim(), "0", "the control plane's database holds the password in the clear");
+});
+
+test("the consumer is also told where its database is", { skip, timeout: 300_000 }, async () => {
+  // A password with no address is not a connection. This is the readable half, which stays
+  // readable on purpose — it is the secret half that could not be composed, not this one.
+  const told = JSON.parse(await must("laptop", `cat /etc/meshboard/database.json`));
+  assert.equal(told.from, "anchor");
+  assert.equal(told.at, "anchor.internal");
+  assert.equal(told.serves.port, 5432);
+  // And the name it resolves to was written by the mesh as well, on this machine.
+  assert.match(await must("laptop", `grep anchor.internal /etc/hosts`), /10\.42\.0\.\d+/);
+});