diff --git a/.changeset/FN-6409-plugin-sdk-dts-inline.md b/.changeset/FN-6409-plugin-sdk-dts-inline.md
new file mode 100644
index 0000000000..0b7cdd850c
--- /dev/null
+++ b/.changeset/FN-6409-plugin-sdk-dts-inline.md
@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Inline the private `@fusion/core` types into the published `@runfusion/fusion/plugin-sdk` declaration entry so standalone external plugins created with `fn plugin new` can typecheck and `pnpm build` cleanly against released Fusion. Human spot-check: `npx @runfusion/fusion@0.42.0 plugin new proof-point-plugin && cd proof-point-plugin && pnpm install && pnpm build`.
diff --git a/packages/cli/src/__tests__/plugin-sdk-export.test.ts b/packages/cli/src/__tests__/plugin-sdk-export.test.ts
index a9ee5891a5..8899323235 100644
--- a/packages/cli/src/__tests__/plugin-sdk-export.test.ts
+++ b/packages/cli/src/__tests__/plugin-sdk-export.test.ts
@@ -51,4 +51,13 @@ describe("plugin-sdk export surface", () => {
     const built = readFileSync(distPath, "utf-8");
     expect(built.includes("@fusion/")).toBe(false);
   });
+
+  it("has no @fusion specifiers in built plugin-sdk declaration artifact when present", () => {
+    const distPath = join(workspaceRoot, "packages", "cli", "dist", "plugin-sdk", "index.d.ts");
+    if (!existsSync(distPath)) {
+      return;
+    }
+    const built = readFileSync(distPath, "utf-8");
+    expect(built.includes("@fusion/")).toBe(false);
+  });
 });
diff --git a/packages/cli/tsup.config.ts b/packages/cli/tsup.config.ts
index 3c608fbcb1..e26827f681 100644
--- a/packages/cli/tsup.config.ts
+++ b/packages/cli/tsup.config.ts
@@ -316,9 +316,18 @@ const pluginSdkBuildConfig = {
   target: "node22",
   tsconfig: join(__dirname, "..", "plugin-sdk", "tsconfig.json"),
   dts: {
-    resolve: true,
+    /*
+     * FNXC:PluginSDK 2026-06-13-12:00:
+     * FN-6409 requires the published @runfusion/fusion/plugin-sdk declaration entry to be self-contained. External plugin authors cannot resolve private @fusion/core types from scaffolded projects, so leaving @fusion/* imports in dist/plugin-sdk/index.d.ts makes tsc fail with TS2307 before ctx parameters can typecheck.
+     */
+    resolve: [/^@fusion\//],
     compilerOptions: {
       rootDir: join(__dirname, ".."),
+      baseUrl: ".",
+      paths: {
+        "@fusion/core": ["../core/src/index.ts"],
+      },
+      removeComments: true,
     },
   },
   noExternal: [/^@fusion\//],