diff --git a/server/src/modules/computers/application/service.test.ts b/server/src/modules/computers/application/service.test.ts
index c438ae50643..b61bb3ea461 100644
--- a/server/src/modules/computers/application/service.test.ts
+++ b/server/src/modules/computers/application/service.test.ts
@@ -1,4 +1,15 @@
 import { describe, it, expect, vi } from "vitest";
+import {
+  existsSync,
+  mkdtempSync,
+  readFileSync,
+  realpathSync,
+  rmSync,
+} from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { spawnSync } from "node:child_process";
+import { remoteProgram } from "../adapters/remote-program.js";
 import { createComputerService } from "./service.js";
 import type { ComputerBackend, ComputerRepository } from "./ports.js";
 import { ComputerError, type ComputerRecord } from "../domain/ledger.js";
@@ -329,6 +340,56 @@ describe("computer ownership", () => {
     await f.service.reconcile();
     expect(f.backend.stop).toHaveBeenCalledOnce();
   });
+  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-")));
+    const local = (value: string) =>
+      value.replace("/home/user/paperclip/", `${temp}/`);
+    vi.mocked(f.backend.remote).mockImplementation(async (_record, input) => {
+      const result = spawnSync(
+        "python3",
+        ["-c", remoteProgram.replaceAll("/home/user/paperclip/", `${temp}/`)],
+        {
+          input: JSON.stringify({
+            ...input,
+            root: local(input.root as string),
+          }),
+          encoding: "utf8",
+        },
+      );
+      if (result.status !== 0) throw new Error(result.stderr);
+      return JSON.parse(result.stdout);
+    });
+    try {
+      await f.attach();
+      const probe = await f.service.admitProbe({
+        ...f.scope,
+        agentId: "agent",
+        probeId: "probe",
+        idleTimeoutMs: 60_000,
+      });
+      expect(probe.remoteCwd).not.toBe(probe.agentHome);
+      const ready = spawnSync("sh", ["-c", "pwd"], {
+        cwd: local(probe.remoteCwd),
+        encoding: "utf8",
+      });
+      expect(ready.status).toBe(0);
+      expect(ready.stdout.trim()).toBe(local(probe.remoteCwd));
+      expect(existsSync(local(probe.agentHome))).toBe(false);
+      const run = await f.admit();
+      expect(run.remoteCwd).toBe(probe.agentHome);
+      expect(existsSync(local(run.agentHome))).toBe(false);
+      const files = await f.service.files({ ...f.scope, agentId: "agent" });
+      await expect(
+        files.seed({ "AGENTS.md": "initial managed instructions" }),
+      ).resolves.toEqual({ seeded: true });
+      expect(
+        readFileSync(join(local(run.agentHome), "AGENTS.md"), "utf8"),
+      ).toBe("initial managed instructions");
+    } finally {
+      rmSync(temp, { recursive: true, force: true });
+    }
+  });
   it("gives harness probes a finite owner without fabricating a heartbeat run", async () => {
     const f = fixture();
     await f.attach();
diff --git a/server/src/modules/computers/application/service.ts b/server/src/modules/computers/application/service.ts
index 70a59657f0b..65aaf69dbc9 100644
--- a/server/src/modules/computers/application/service.ts
+++ b/server/src/modules/computers/application/service.ts
@@ -372,7 +372,9 @@ sys.stdout.write(output);sys.stderr.write(error);sys.exit(child.returncode)
       record.ledger.placements[input.sessionKey] ??= {
         id: randomUUID(),
         root: `${base(record)}/agents/${input.agentId}`,
-        cwd: `${base(record)}/agents/${input.agentId}`,
+        cwd: input.probeId
+          ? `${base(record)}/probes/${input.probeId}`
+          : `${base(record)}/agents/${input.agentId}`,
       };
       return { record: structuredClone(record), owner: structuredClone(owner) };
     });
@@ -380,6 +382,16 @@ sys.stdout.write(output);sys.stderr.write(error);sys.exit(child.returncode)
     await backend.claim(result.record);
     await backend.advance(result.record, result.owner);
     await backend.renew(result.record);
+    if (input.probeId) {
+      // Readiness commands run before managed-home preparation. Give them an
+      // existing workspace without creating the personal home: an absent home
+      // must remain eligible for the first atomic managed-file seed.
+      await backend.remote(result.record, {
+        action: "seed",
+        root: result.record.ledger.placements[input.sessionKey]!.cwd,
+        files: {},
+      });
+    }
     const active = await repository.update(input, (record) => {
       const owner = exactOwner(record, ref(result.record, result.owner));
       if (owner.phase !== "starting")