diff --git a/dagger-module.toml b/dagger-module.toml
index 3d53cf8..7465738 100644
--- a/dagger-module.toml
+++ b/dagger-module.toml
@@ -1,10 +1,6 @@
 name = "java-sdk"
-engineVersion = "v1.0.0-0"
+engineVersion = "v1.0.0-beta.10"
 
 [runtime]
   source = "dang"
 
-[[dependencies]]
-  name = "polyfill"
-  source = "github.com/dagger/polyfill@main"
-  pin = "e90bbfc4843258a877a3a95b8db1571e7981e65f"
diff --git a/dagger.json b/dagger.json
index e38c38e..95b85ed 100644
--- a/dagger.json
+++ b/dagger.json
@@ -1,14 +1,7 @@
 {
   "name": "java-sdk",
-  "engineVersion": "latest",
+  "engineVersion": "v1.0.0-beta.10",
   "sdk": {
     "source": "dang"
-  },
-  "dependencies": [
-    {
-      "name": "polyfill",
-      "source": "github.com/dagger/polyfill@main",
-      "pin": "e90bbfc4843258a877a3a95b8db1571e7981e65f"
-    }
-  ]
+  }
 }
diff --git a/dagger.lock b/dagger.lock
index f8cfb64..617173c 100644
--- a/dagger.lock
+++ b/dagger.lock
@@ -1,4 +1,3 @@
 [["version","1"]]
 ["","git.head",["https://github.com/dagger/dang-sdk"],"c724eec4270870aae489daa9f3cb8cbacfb44680","float"]
 ["","git.head",["https://github.com/dagger/sdk-sdk"],"8c164424b7a8a37b33a77367ef7547490d5b87b5","float"]
-["","git.ref",["https://github.com/dagger/polyfill","main"],"ec3ea84a2351b4beb06ecece951f2e5ef66509ff","float"]
\ No newline at end of file
diff --git a/main.dang b/main.dang
index 5673c73..0af8b36 100644
--- a/main.dang
+++ b/main.dang
@@ -56,14 +56,8 @@ type JavaSdk {
       rawPath.trimSuffix("/")
     }
 
-    let before = if (modPath == ".") {
-      ws.directory("/", include: ["**"])
-    } else {
-      ws.directory("/", include: [modPath + "/**"])
-    }
-
     let selectedTemplate = if (template == "") { "default" } else { template }
-    before.withDirectory(modPath, renderedTemplate(name, selectedTemplate)).changes(before)
+    ws.fork.withNewDirectory("/" + modPath, renderedTemplate(name, selectedTemplate)).changes
   }
 
   """
@@ -96,14 +90,14 @@ type JavaSdk {
   (currentModule.asSDK.modules). So running from a subdirectory acts on the
   project you're in — and the projects beneath it — not the whole workspace.
 
-  Discovery is the polyfill's cwd-aware findConfigDirs (dagger/dagger#13688);
+  Discovery is the engine's cwd-aware Workspace.findConfigDirs;
   this maps its cwd-relative results to workspace-root-relative paths and keeps
   the ones this SDK manages, whether they use dagger-module.toml or dagger.json.
   """
   pub modules(ws: Workspace!): [Mod!]! {
     let managed = ws.sdk(name: currentModule.name).modules.{{source}}
     let cwd = normalizePath(ws.cwd)
-    polyfill.workspace(ws)
+    ws
       .findConfigDirs(moduleConfigFilenames, exclude: ["**/target/**"])
       .map { dir => moduleRelPath(cwd, dir) }
       .uniq
diff --git a/mod.dang b/mod.dang
index 03102a9..01c3798 100644
--- a/mod.dang
+++ b/mod.dang
@@ -198,13 +198,10 @@ type Mod {
   Stage the vendored SDK + generated entrypoint for one module.
   """
   let generateModule(ws: Workspace!, modPathArg: String!): Changeset! {
-    # Native module-source resolution (Directory.asModuleSource, Query.moduleSource)
-    # fails from module code: SDK and user-defaults loading need the requester's host
-    # session. The polyfill resolves the source from a nested client that has one.
     # Anchor rootPath at "/" so a non-root workspace cwd is not prefixed again.
-    let modSource = polyfill.workspace(ws).moduleSource("/" + modPathArg)
-    let name = modSource.core.moduleName
-    let introspectionJSON = modSource.core.introspectionSchemaJSON
+    let modSource = ws.moduleSource("/" + modPathArg)
+    let name = modSource.moduleName
+    let introspectionJSON = modSource.introspectionSchemaJSON
     let vendored = vendoredSdk(introspectionJSON, name)
 
     # the module as committed, with the whole committed sdk/ dropped (source and
@@ -216,21 +213,18 @@ type Mod {
       .withoutDirectory("src/generated")
     let entrypoint = generatedEntrypoint(baseDir, name)
 
-    let before = if (modPathArg == ".") {
-      ws.directory("/", include: ["**"])
-    } else {
-      ws.directory("/", include: [modPathArg + "/**"])
-    }
-    let staged = before
-      .withDirectory(joinPath(modPathArg, "sdk"), vendored)
-      .withDirectory(joinPath(modPathArg, "src/generated/java"), entrypoint)
+    # Stage through a workspace fork: the changeset comes back measured from
+    # the caller's cwd, the way the client applies it.
+    let staged = ws.fork
+      .withNewDirectory("/" + joinPath(modPathArg, "sdk"), vendored)
+      .withNewDirectory("/" + joinPath(modPathArg, "src/generated/java"), entrypoint)
 
     if (vendorSdkJar) {
       staged
-        .withDirectory(joinPath(modPathArg, "sdk/repo"), vendoredSdkJar(introspectionJSON, name))
-        .changes(before)
+        .withNewDirectory("/" + joinPath(modPathArg, "sdk/repo"), vendoredSdkJar(introspectionJSON, name))
+        .changes
     } else {
-      staged.changes(before)
+      staged.changes
     }
   }