diff --git a/.changeset/wide-snails-feel.md b/.changeset/wide-snails-feel.md
new file mode 100644
index 000000000..a845151cc
--- /dev/null
+++ b/.changeset/wide-snails-feel.md
@@ -0,0 +1,2 @@
+---
+---
diff --git a/.dependency-cruiser.cjs b/.dependency-cruiser.cjs
index 186f65780..91d26ddd3 100644
--- a/.dependency-cruiser.cjs
+++ b/.dependency-cruiser.cjs
@@ -82,6 +82,17 @@ module.exports = {
         pathNot: "^packages/(hunk-git|hunk-vcs)/src/|^packages/hunk/src/extension-api/",
       },
     },
+    {
+      name: "hunk-jj-stays-on-vcs-contract",
+      comment:
+        "@hunk/jj owns the Jujutsu provider and may reach only its local modules, the public extension contract, and explicit dependency-bottom @hunk/vcs leaves.",
+      severity: "error",
+      from: { path: "^packages/hunk-jj/src/" },
+      to: {
+        path: "^packages/",
+        pathNot: "^packages/(hunk-jj|hunk-vcs)/src/|^packages/hunk/src/extension-api/",
+      },
+    },
     {
       name: "lib-is-a-leaf",
       comment:
@@ -192,7 +203,7 @@ module.exports = {
       severity: "error",
       from: {
         path: "^packages/(?!hunk/)",
-        pathNot: "^packages/hunk-git/",
+        pathNot: "^packages/hunk-(git|jj)/",
       },
       to: { path: "^packages/hunk/src/" },
     },
diff --git a/bun.lock b/bun.lock
index d3e7e8a38..17be3509e 100644
--- a/bun.lock
+++ b/bun.lock
@@ -7,6 +7,7 @@
       "devDependencies": {
         "@changesets/changelog-github": "^0.7.0",
         "@hunk/git": "workspace:*",
+        "@hunk/jj": "workspace:*",
         "@hunk/session-broker": "workspace:*",
         "@hunk/session-broker-bun": "workspace:*",
         "@hunk/session-broker-core": "workspace:*",
@@ -79,6 +80,14 @@
         "hunkdiff": "workspace:*",
       },
     },
+    "packages/hunk-jj": {
+      "name": "@hunk/jj",
+      "version": "0.0.0",
+      "dependencies": {
+        "@hunk/vcs": "workspace:*",
+        "hunkdiff": "workspace:*",
+      },
+    },
     "packages/hunk-vcs": {
       "name": "@hunk/vcs",
       "version": "0.0.0",
@@ -140,6 +149,8 @@
 
     "@hunk/git": ["@hunk/git@workspace:packages/hunk-git"],
 
+    "@hunk/jj": ["@hunk/jj@workspace:packages/hunk-jj"],
+
     "@hunk/session-broker": ["@hunk/session-broker@workspace:packages/session-broker"],
 
     "@hunk/session-broker-bun": ["@hunk/session-broker-bun@workspace:packages/session-broker-bun"],
diff --git a/knip.json b/knip.json
index 7e1dde9f4..d9c76b24c 100644
--- a/knip.json
+++ b/knip.json
@@ -42,6 +42,11 @@
       "entry": ["src/**/*.test.ts"],
       "project": ["src/**/*.ts"]
     },
+    "packages/hunk-jj": {
+      "entry": ["src/**/*.test.ts"],
+      "project": ["src/**/*.ts"],
+      "ignoreExportsUsedInFile": true
+    },
     "packages/hunk-vcs": {
       "entry": ["src/**/*.test.ts"],
       "project": ["src/**/*.ts"]
diff --git a/nix/bun.lock.nix b/nix/bun.lock.nix
index 0a4348a83..f154ef058 100644
--- a/nix/bun.lock.nix
+++ b/nix/bun.lock.nix
@@ -54,6 +54,7 @@
     hash = "sha512-vo/MwCnpJAVHBkGzWjCJ28wF45fYHAfbPZcH2rodZODHtch2GHA94KtMfusmVycTUtsLAsaNsHhtY6P8X3RQsA==";
   };
   "@hunk/git" = copyPathToStore ../packages/hunk-git;
+  "@hunk/jj" = copyPathToStore ../packages/hunk-jj;
   "@hunk/session-broker" = copyPathToStore ../packages/session-broker;
   "@hunk/session-broker-bun" = copyPathToStore ../packages/session-broker-bun;
   "@hunk/session-broker-core" = copyPathToStore ../packages/session-broker-core;
diff --git a/package.json b/package.json
index 0f946bde7..096ad3984 100644
--- a/package.json
+++ b/package.json
@@ -78,6 +78,7 @@
   "devDependencies": {
     "@changesets/changelog-github": "^0.7.0",
     "@hunk/git": "workspace:*",
+    "@hunk/jj": "workspace:*",
     "@hunk/session-broker": "workspace:*",
     "@hunk/session-broker-bun": "workspace:*",
     "@hunk/session-broker-core": "workspace:*",
diff --git a/packages/hunk-jj/package.json b/packages/hunk-jj/package.json
new file mode 100644
index 000000000..8c0e540d5
--- /dev/null
+++ b/packages/hunk-jj/package.json
@@ -0,0 +1,26 @@
+{
+  "name": "@hunk/jj",
+  "version": "0.0.0",
+  "private": true,
+  "description": "Private statically bundled Jujutsu provider for Hunk.",
+  "license": "MIT",
+  "files": [
+    "src"
+  ],
+  "type": "module",
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "types": "./src/index.ts",
+      "import": "./src/index.ts"
+    }
+  },
+  "dependencies": {
+    "@hunk/vcs": "workspace:*",
+    "hunkdiff": "workspace:*"
+  },
+  "engines": {
+    "bun": ">=1.3.14",
+    "node": ">=22"
+  }
+}
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/commands.test.ts b/packages/hunk-jj/src/commands.test.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/commands.test.ts
rename to packages/hunk-jj/src/commands.test.ts
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/commands.ts b/packages/hunk-jj/src/commands.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/commands.ts
rename to packages/hunk-jj/src/commands.ts
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/history.test.ts b/packages/hunk-jj/src/history.test.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/history.test.ts
rename to packages/hunk-jj/src/history.test.ts
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/history.ts b/packages/hunk-jj/src/history.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/history.ts
rename to packages/hunk-jj/src/history.ts
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/index.test.ts b/packages/hunk-jj/src/index.test.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/index.test.ts
rename to packages/hunk-jj/src/index.test.ts
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/index.ts b/packages/hunk-jj/src/index.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/index.ts
rename to packages/hunk-jj/src/index.ts
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/source.test.ts b/packages/hunk-jj/src/source.test.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/source.test.ts
rename to packages/hunk-jj/src/source.test.ts
diff --git a/packages/hunk/src/extensions/default/vcs/jujutsu/source.ts b/packages/hunk-jj/src/source.ts
similarity index 100%
rename from packages/hunk/src/extensions/default/vcs/jujutsu/source.ts
rename to packages/hunk-jj/src/source.ts
diff --git a/packages/hunk/src/extensions/default/vcs/index.ts b/packages/hunk/src/extensions/default/vcs/index.ts
index 494032ca6..e213e6968 100644
--- a/packages/hunk/src/extensions/default/vcs/index.ts
+++ b/packages/hunk/src/extensions/default/vcs/index.ts
@@ -1,5 +1,5 @@
 import gitExtension from "@hunk/git";
-import jjExtension from "./jujutsu";
+import jjExtension from "@hunk/jj";
 import slExtension from "./sapling";
 import { runExtensionFactory } from "../../runExtension";
 import {
diff --git a/scripts/hunk-jj-package.test.ts b/scripts/hunk-jj-package.test.ts
new file mode 100644
index 000000000..3f4d6bfc9
--- /dev/null
+++ b/scripts/hunk-jj-package.test.ts
@@ -0,0 +1,54 @@
+import { describe, expect, test } from "bun:test";
+import jjExtension, { JjVcsAdapter } from "@hunk/jj";
+import { readFileSync } from "node:fs";
+import { join, resolve } from "node:path";
+
+const REPO_ROOT = resolve(import.meta.dir, "..");
+const PACKAGE_ROOT = join(REPO_ROOT, "packages", "hunk-jj");
+
+describe("@hunk/jj package boundary", () => {
+  test("exports only the explicit Jujutsu provider entry", () => {
+    const manifest = JSON.parse(readFileSync(join(PACKAGE_ROOT, "package.json"), "utf8")) as {
+      name: string;
+      private: boolean;
+      files: string[];
+      exports: Record<string, unknown>;
+      dependencies: Record<string, string>;
+    };
+
+    expect(manifest.name).toBe("@hunk/jj");
+    expect(manifest.private).toBe(true);
+    expect(manifest.files).toEqual(["src"]);
+    expect(manifest.exports).toEqual({
+      ".": {
+        types: "./src/index.ts",
+        import: "./src/index.ts",
+      },
+    });
+    expect(manifest.dependencies).toEqual({
+      "@hunk/vcs": "workspace:*",
+      hunkdiff: "workspace:*",
+    });
+  });
+
+  test("registers the private workspace without leaking it into hunkdiff", () => {
+    const rootManifest = JSON.parse(readFileSync(join(REPO_ROOT, "package.json"), "utf8")) as {
+      devDependencies: Record<string, string>;
+    };
+    const hunkManifest = readFileSync(join(REPO_ROOT, "packages", "hunk", "package.json"), "utf8");
+    const bunLock = readFileSync(join(REPO_ROOT, "bun.lock"), "utf8");
+    const nixLock = readFileSync(join(REPO_ROOT, "nix", "bun.lock.nix"), "utf8");
+
+    expect(rootManifest.devDependencies["@hunk/jj"]).toBe("workspace:*");
+    expect(hunkManifest).not.toContain("@hunk/jj");
+    expect(hunkManifest).not.toContain("workspace:");
+    expect(bunLock).toContain('"packages/hunk-jj": {');
+    expect(bunLock).toContain('"@hunk/jj@workspace:packages/hunk-jj"');
+    expect(nixLock).toContain('"@hunk/jj" = copyPathToStore ../packages/hunk-jj;');
+  });
+
+  test("loads its provider entrypoint through the workspace", () => {
+    expect(typeof jjExtension).toBe("function");
+    expect(JjVcsAdapter.id).toBe("jj");
+  });
+});
diff --git a/scripts/source-boundaries.test.ts b/scripts/source-boundaries.test.ts
index 64ba69643..bb82c1751 100644
--- a/scripts/source-boundaries.test.ts
+++ b/scripts/source-boundaries.test.ts
@@ -8,6 +8,7 @@ const CORE_ROOT = join(SRC_ROOT, "core");
 const EXTENSIONS_ROOT = join(SRC_ROOT, "extensions");
 const BUNDLED_PROVIDER_ROOT = join(EXTENSIONS_ROOT, "default", "vcs");
 const GIT_PACKAGE_ROOT = join(REPO_ROOT, "packages", "hunk-git", "src");
+const JJ_PACKAGE_ROOT = join(REPO_ROOT, "packages", "hunk-jj", "src");
 const VCS_PACKAGE_ROOT = join(REPO_ROOT, "packages", "hunk-vcs", "src");
 const REVIEW_MODEL_ROOT = join(CORE_ROOT, "review");
 // The published extension contract, which the review model may name for the annotation shapes
@@ -167,7 +168,7 @@ function unexpectedProviderImports() {
     "@hunk/vcs/path",
     "@hunk/vcs/source",
   ]);
-  return [BUNDLED_PROVIDER_ROOT, GIT_PACKAGE_ROOT].flatMap((providerRoot) =>
+  return [BUNDLED_PROVIDER_ROOT, GIT_PACKAGE_ROOT, JJ_PACKAGE_ROOT].flatMap((providerRoot) =>
     sourceFiles(providerRoot).flatMap((path) =>
       importSpecifiers(path)
         // The lightweight scanner can match prose ending in `from "…"`; module specifiers
@@ -182,7 +183,10 @@ function unexpectedProviderImports() {
           ) {
             return false;
           }
-          return !(path === join(BUNDLED_PROVIDER_ROOT, "index.ts") && specifier === "@hunk/git");
+          return !(
+            path === join(BUNDLED_PROVIDER_ROOT, "index.ts") &&
+            (specifier === "@hunk/git" || specifier === "@hunk/jj")
+          );
         })
         .map((specifier) => `${repoPath(path)} -> ${specifier}`),
     ),
@@ -312,6 +316,7 @@ describe("source architecture boundaries", () => {
   test("keeps bundled providers on the public contract and explicit VCS helper leaves", () => {
     expect(forbiddenImports(BUNDLED_PROVIDER_ROOT, CORE_ROOT)).toEqual([]);
     expect(escapingImports(GIT_PACKAGE_ROOT, [GIT_PACKAGE_ROOT])).toEqual([]);
+    expect(escapingImports(JJ_PACKAGE_ROOT, [JJ_PACKAGE_ROOT])).toEqual([]);
     expect(unexpectedProviderImports()).toEqual([]);
   });
 
diff --git a/tsconfig.json b/tsconfig.json
index f6abe2bba..d39e36a65 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -15,6 +15,7 @@
     "baseUrl": ".",
     "paths": {
       "@hunk/git": ["packages/hunk-git/src/index.ts"],
+      "@hunk/jj": ["packages/hunk-jj/src/index.ts"],
       "@hunk/session-broker": ["packages/session-broker/src/index.ts"],
       "@hunk/session-broker-bun": ["packages/session-broker-bun/src/index.ts"],
       "@hunk/session-broker-core": ["packages/session-broker-core/src/index.ts"],