diff --git a/.quixos-subtree-source.json b/.quixos-subtree-source.json
index b3a52cb..85521d9 100644
--- a/.quixos-subtree-source.json
+++ b/.quixos-subtree-source.json
@@ -1,7 +1,7 @@
 {
   "version": 1,
   "sourceRepo": "https://gitea-external.egads.tutti.syntaxblitz.net/quixos/quixos",
-  "sourceCommit": "abc91ab1cbbd61ffd7f0a49dbc5768598ac8745c",
+  "sourceCommit": "932fe7714761fb8b5db4bd6401357cdff762a428",
   "sourcePath": "quixos-protocol",
   "exportName": "quixos-protocol",
   "mirrorRemote": "https://gitea-external.egads.tutti.syntaxblitz.net/quixos/quixos-protocol.git"
diff --git a/src/execution-world/artifacts.ts b/src/execution-world/artifacts.ts
index e5fbcea..85f05f1 100644
--- a/src/execution-world/artifacts.ts
+++ b/src/execution-world/artifacts.ts
@@ -11,7 +11,7 @@ export interface ArtifactFile {
 export interface ArtifactImplementation {
   id: string;
   target: string;
-  compatibility: "quixos-service-v1" | "quixos-js-module-v1";
+  compatibility: "quixos-service-v1" | "quixos-js-module-v1" | "quixos-restricted-module-v1";
   path: string;
   ports: "quixos-transaction-ports-v1";
   registryExport?: string;
@@ -225,7 +225,11 @@ export function parseArtifactGroup(value: unknown): ArtifactGroup {
         ["registryExport"],
         path,
       );
-      if (entry.compatibility !== "quixos-service-v1" && entry.compatibility !== "quixos-js-module-v1")
+      if (
+        !["quixos-service-v1", "quixos-js-module-v1", "quixos-restricted-module-v1"].includes(
+          String(entry.compatibility),
+        )
+      )
         fail(path, "Unsupported artifact ABI");
       if (entry.ports !== "quixos-transaction-ports-v1") fail(path, "Unsupported transaction port ABI");
       if (
@@ -233,7 +237,9 @@ export function parseArtifactGroup(value: unknown): ArtifactGroup {
         (entry.target !== "server" || entry.registryExport !== undefined)
       )
         fail(path, "Service must target server and has no JS registry export");
-      if (entry.compatibility === "quixos-js-module-v1") text(entry.registryExport, `${path}.registryExport`);
+      if (entry.compatibility !== "quixos-service-v1") text(entry.registryExport, `${path}.registryExport`);
+      if (entry.compatibility === "quixos-restricted-module-v1" && entry.target !== "server")
+        fail(path, "Restricted modules must target server");
       const exports = array(entry.exports, `${path}.exports`).map((value) => text(value, `${path}.exports`));
       unique(exports, `${path}.exports`);
       const files = parseArtifactFiles(entry.files, `${path}.files`);
@@ -300,6 +306,11 @@ export function checkPackageCoverage(
     for (const id of implementation.exports) {
       const entry = expected.exports.find((e) => e.id === id);
       if (!entry) fail(implementation.id, `Unknown export ${id}`);
+      if (
+        implementation.compatibility === "quixos-restricted-module-v1" &&
+        (entry!.execution.kind === "remote" || !entry!.execution.targets.includes("server"))
+      )
+        fail(implementation.id, `Export ${id} does not promise restricted server computation`);
       if (
         implementation.target !== "server" &&
         (!entry?.execution ||
diff --git a/src/execution-world/installation.ts b/src/execution-world/installation.ts
index 3c9d26d..a6eafc3 100644
--- a/src/execution-world/installation.ts
+++ b/src/execution-world/installation.ts
@@ -113,6 +113,8 @@ export interface ExecutionInstallation {
     readonly root: string;
     readonly service?: ArtifactImplementation;
     readonly module?: ArtifactImplementation;
+    /** Checked candidate only; the qualified host verifies its import surface and SDK. */
+    readonly restricted?: ArtifactImplementation;
     readonly browserImplementation?: ArtifactImplementation;
     readonly browserURL?: string;
     readonly browserRegistry?: string;
@@ -251,6 +253,11 @@ function assembleExecutionInstallation(
           exports: exports.map((entry) => entry.id),
         })
       : undefined;
+    const restrictedCandidates = manifest.implementations.filter(
+      (entry) => entry.compatibility === "quixos-restricted-module-v1",
+    );
+    if (restrictedCandidates.length > 1) fail(revision, "Ambiguous restricted module candidates");
+    const restricted = restrictedCandidates[0];
     const browserExports = exports.filter(
       (entry) =>
         entry.execution.kind !== "remote" &&
@@ -258,7 +265,13 @@ function assembleExecutionInstallation(
     );
     if (!browserExports.length) {
       if (selection.browser) fail(revision, "Package has no browser exports to select");
-      packages.push({ revision, root, ...(service ? { service } : {}), ...(module ? { module } : {}) });
+      packages.push({
+        revision,
+        root,
+        ...(service ? { service } : {}),
+        ...(module ? { module } : {}),
+        ...(restricted ? { restricted } : {}),
+      });
       continue;
     }
     const browser = selectArtifactImplementation(manifest, {
@@ -289,6 +302,7 @@ function assembleExecutionInstallation(
       root,
       ...(service ? { service } : {}),
       ...(module ? { module } : {}),
+      ...(restricted ? { restricted } : {}),
       browserImplementation: browser,
       browserURL: contentArtifactUrl(entry),
       browserRegistry: browser.registryExport,
diff --git a/src/execution-world/placement.ts b/src/execution-world/placement.ts
index 1b8fe01..5d19bdb 100644
--- a/src/execution-world/placement.ts
+++ b/src/execution-world/placement.ts
@@ -23,6 +23,39 @@ export interface ImportFinding {
   readonly detail: string;
   readonly line: number | null;
 }
+export const restrictedSDKSpecifier = "quixos:restricted-sdk/v1";
+export const restrictedSDKPath = "share/quixos/restricted/core.mjs";
+
+/** Mechanical candidate checks, not authorization or an engine-safety proof.
+ * The caller must first verify the manifest and all declared file digests. */
+export async function inspectRestrictedImplementation(
+  revision: string,
+  implementation: ArtifactImplementation,
+  read: ArtifactReader,
+  qualifiedSDKDigest?: string,
+): Promise<ImportFinding[]> {
+  const entry = implementation.files.find((file) => file.path === implementation.path);
+  const sdk = implementation.files.find((file) => file.path === restrictedSDKPath);
+  if (
+    implementation.compatibility !== "quixos-restricted-module-v1" ||
+    implementation.target !== "server" ||
+    implementation.files.length !== 2 ||
+    !entry ||
+    !sdk ||
+    entry === sdk ||
+    entry.mediaType !== "text/javascript" ||
+    sdk.mediaType !== "text/javascript" ||
+    !/^[$A-Z_a-z][$\w]*$/.test(implementation.registryExport ?? "")
+  )
+    return [{ code: "RESTRICTED_CLOSURE", detail: "Expected one closed module and the restricted SDK", line: null }];
+  if (qualifiedSDKDigest && sdk.digest !== qualifiedSDKDigest)
+    return [{ code: "RESTRICTED_SDK_UNSUPPORTED", detail: "SDK differs from the qualified host profile", line: null }];
+  if (entry.bytes > 1024 * 1024 || sdk.bytes > 2 * 1024 * 1024)
+    return [{ code: "ANALYSIS_LIMIT", detail: "Restricted closure exceeds the source budget", line: null }];
+  return inspectJavaScriptSurface(Buffer.from(await read(revision, entry.path, entry.bytes)).toString("utf8"), [
+    restrictedSDKSpecifier,
+  ]);
+}
 const nativeImports = new Set(builtinModules.flatMap((name) => [name, name.replace(/^node:/, "")]));
 const ambient = new Set([
   "process",
@@ -136,10 +169,8 @@ export function inspectJavaScriptSurface(source: string, checkedSDKImports: read
   return findings;
 }
 
-/** Derived metadata only. Browser/server portability and available targets say
- * nothing about sandbox eligibility. Build reports have no platform approval
- * catalog, so they conservatively require VM placement. A host can override
- * placement only for independently reviewed, exact restricted-code approvals. */
+/** Derived metadata only. A build report can describe a closed candidate but
+ * cannot qualify the host's engine, SDK, OS sandbox or resource controller. */
 export async function reportExecutionPlacement(
   plan: ExecutionPlan,
   installation: ExecutionInstallation,
@@ -156,11 +187,13 @@ export async function reportExecutionPlacement(
   const packages = await Promise.all(
     installation.packages.map(async (pkg) => {
       const implementations: { id: string; digest: string; compatibility: string; findings: ImportFinding[] }[] = [];
-      for (const implementation of [pkg.service, pkg.module].filter(
+      for (const implementation of [pkg.service, pkg.module, pkg.restricted].filter(
         (entry): entry is ArtifactImplementation => !!entry,
       )) {
         let findings: ImportFinding[];
-        if (implementation.compatibility === "quixos-js-module-v1") {
+        if (implementation.compatibility === "quixos-restricted-module-v1")
+          findings = await inspectRestrictedImplementation(pkg.revision, implementation, read);
+        else if (implementation.compatibility === "quixos-js-module-v1") {
           const file = implementation.files.find((file) => file.path === implementation.path)!;
           if (!file || file.bytes > 1024 * 1024)
             findings = [
@@ -192,7 +225,14 @@ export async function reportExecutionPlacement(
         revision: pkg.revision,
         requiresVM: implementations.length > 0,
         restrictedEligible: false as const,
-        reason: "NO_QUALIFIED_RESTRICTED_RUNTIME",
+        reason: pkg.restricted ? "HOST_PROFILE_QUALIFICATION_REQUIRED" : "NO_RESTRICTED_IMPLEMENTATION",
+        restrictedCandidate: pkg.restricted
+          ? {
+              digest: pkg.restricted.contentDigest,
+              exports: pkg.restricted.exports,
+              compatible: implementations.find((entry) => entry.id === pkg.restricted!.id)!.findings.length === 0,
+            }
+          : null,
         implementations,
       };
     }),