Bound initial computer home uploads and exclude runtime state

Stream initial personal files through bounded chunks into private staging and atomically publish without replacing an existing home. Keep the home-level runtime directory out of instruction enumeration and seeding while preserving nested user content.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/modules/computers/application/service.test.ts

@@ -545,6 +545,32 @@ with open(output,'wb') as out,open(error,'wb') as err:
       rmSync(temp, { recursive: true, force: true });
     }
   });
+  it("bounds initial seed requests and aborts a failed upload without publishing", async () => {
+    const f = fixture();
+    await f.attach();
+    const files = await f.service.files({ ...f.scope, agentId: "agent" });
+    vi.mocked(f.backend.remote).mockImplementation(async (_record, input) => {
+      if (input.action === "seed-begin") return { started: true };
+      if (input.action === "seed-commit") return { seeded: true };
+      return {};
+    });
+    await expect(files.seedBytes({ "large.bin": Buffer.alloc(2 * 1024 * 1024 + 1) })).resolves.toEqual({ seeded: true });
+    const chunks = vi.mocked(f.backend.remote).mock.calls.map(([, input]) => input).filter(input => input.action === "seed-chunk");
+    expect(chunks).toHaveLength(3);
+    expect(chunks.map(input => input.offset)).toEqual([0, 1024 * 1024, 2 * 1024 * 1024]);
+    expect(chunks.every(input => Buffer.from(input.base64 as string, "base64").length <= 1024 * 1024)).toBe(true);
+    vi.mocked(f.backend.remote).mockClear();
+    await expect(files.seedFiles((async function* () {
+      yield { path: "first", offset: 0, bytes: Buffer.from("first") };
+      throw new Error("source disappeared");
+    })())).rejects.toThrow("source disappeared");
+    const actions = vi.mocked(f.backend.remote).mock.calls.map(([, input]) => input.action);
+    expect(actions).toEqual(["seed-begin", "seed-chunk", "seed-abort"]);
+    vi.mocked(f.backend.remote).mockResolvedValue({ started: false });
+    let read = false;
+    await expect(files.seedFiles((async function* () { read = true; yield { path: "unused", offset: 0, bytes: Buffer.alloc(0) }; })())).resolves.toEqual({ seeded: false });
+    expect(read).toBe(false);
+  });
   it("realizes probe cwd before readiness without consuming the initial personal-home seed", async () => {
     const f = fixture();
     const temp = realpathSync(mkdtempSync(join(tmpdir(), "computer-probe-")));

server/src/modules/computers/application/service.ts

@@ -687,9 +687,33 @@ finally:
         base64: bytes.toString("base64"),
         expectedSha256,
       });
+    const seedFiles = async (chunks: AsyncIterable<{ path: string; offset: number; bytes: Buffer }>): Promise<{ seeded: boolean }> => {
+      const seedId = randomUUID();
+      const started = await remote({ action: "seed-begin", seedId });
+      if (!started.started) return { seeded: false };
+      try {
+        for await (const chunk of chunks) {
+          if (chunk.bytes.length > 1024 * 1024) throw new ComputerError("invalid", "Initial home chunk exceeds its size limit");
+          await remote({ action: "seed-chunk", seedId, path: chunk.path, offset: chunk.offset, base64: chunk.bytes.toString("base64") });
+        }
+        return await remote({ action: "seed-commit", seedId });
+      } catch (error) {
+        await remote({ action: "seed-abort", seedId }).catch(() => undefined);
+        throw error;
+      }
+    };
+    const seedBytes = async (files: Record<string, Buffer>): Promise<{ seeded: boolean }> => seedFiles((async function* () {
+      for (const [path, bytes] of Object.entries(files)) {
+        for (let offset = 0; offset < Math.max(1, bytes.length); offset += 1024 * 1024) {
+          yield { path, offset, bytes: bytes.subarray(offset, offset + 1024 * 1024) };
+        }
+      }
+    })());
     return {
       root,
       readBytes,
+      seedFiles,
+      seedBytes,
       writeBytes,
       async read(path: string) {
         const value = await readBytes(path);
@@ -729,29 +753,8 @@ finally:
       ): Promise<{ sha256: string }> {
         return remote({ action: "move", path: from, to, expectedSha256 });
       },
-      async seedBytes(
-        files: Record<string, Buffer>,
-      ): Promise<{ seeded: boolean }> {
-        return remote({
-          action: "seed",
-          files: Object.fromEntries(
-            Object.entries(files).map(([key, value]) => [
-              key,
-              value.toString("base64"),
-            ]),
-          ),
-        });
-      },
       async seed(files: Record<string, string>): Promise<{ seeded: boolean }> {
-        return remote({
-          action: "seed",
-          files: Object.fromEntries(
-            Object.entries(files).map(([key, value]) => [
-              key,
-              Buffer.from(value).toString("base64"),
-            ]),
-          ),
-        });
+        return seedBytes(Object.fromEntries(Object.entries(files).map(([path, content]) => [path, Buffer.from(content)])));
       },
     };
   }