diff --git a/server/src/modules/computers/application/service.test.ts b/server/src/modules/computers/application/service.test.ts
index ac41da391d4..3a908f9fdcd 100644
--- a/server/src/modules/computers/application/service.test.ts
+++ b/server/src/modules/computers/application/service.test.ts
@@ -621,6 +621,35 @@ with open(output,'wb') as out,open(error,'wb') as err:
       rmSync(temp, { recursive: true, force: true });
     }
   });
+  it("admits an unsaved-agent probe in a bounded company-scoped temporary home", async () => {
+    const f = fixture();
+    await f.attach();
+    const probe = await f.service.admitProbe({ ...f.scope, probeId: "unsaved", idleTimeoutMs: 60_000 });
+    const record = await f.repository.get(f.scope);
+    const owner = record.ledger.owners.find((entry) => entry.id === probe.owner.ownerId)!;
+    expect(owner.agentId).toBeUndefined();
+    expect(owner.runId).toBeUndefined();
+    expect(owner.probeId).toBe("unsaved");
+    expect(probe.remoteCwd).toBe(`/home/user/paperclip/${f.scope.companyId}/probes/unsaved`);
+    expect(probe.agentHome).toBe(probe.remoteCwd);
+    expect(Object.keys(record.ledger.placements)).toEqual(["probe-unsaved"]);
+    await expect(f.service.realizeWorkspace({ ...f.scope, owner: probe.owner, mode: "shared" }))
+      .resolves.toMatchObject({ remoteCwd: probe.remoteCwd, agentHome: probe.agentHome });
+    await expect(f.service.realizeWorkspace({ ...f.scope, owner: probe.owner, mode: "shared", projectId: "project" }))
+      .rejects.toMatchObject({ code: "conflict" });
+    await expect(f.service.admitProbe({ ...f.scope, companyId: "foreign", probeId: "other", idleTimeoutMs: 60_000 }))
+      .rejects.toMatchObject({ code: "not_found" });
+    f.advance(60_001);
+    await f.service.reconcile();
+    expect(f.repository.runState).not.toHaveBeenCalled();
+    expect(f.backend.retire).toHaveBeenCalledOnce();
+  });
+  it("still requires an agent for a real heartbeat admission", async () => {
+    const f = fixture();
+    await f.attach();
+    await expect(f.service.admit({ ...f.scope, runId: "run", sessionKey: "session", idleTimeoutMs: 60_000 }))
+      .rejects.toMatchObject({ code: "invalid" });
+  });
   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 6ef886c7f5b..1ea48de01a7 100644
--- a/server/src/modules/computers/application/service.ts
+++ b/server/src/modules/computers/application/service.ts
@@ -358,14 +358,16 @@ finally:
   }
   async function admit(
     input: Scope & {
-      agentId: string;
+      agentId?: string;
       runId?: string;
       probeId?: string;
       sessionKey: string;
       idleTimeoutMs: number;
     },
   ) {
-    segment(input.agentId);
+    if (input.agentId) segment(input.agentId);
+    if (!input.agentId && !input.probeId)
+      throw new ComputerError("invalid", "A computer run requires an agent");
     if ((!input.runId && !input.probeId) || (input.runId && input.probeId))
       throw new ComputerError(
         "invalid",
@@ -414,17 +416,22 @@ finally:
         };
         record.ledger.owners.push(owner);
       }
-      record.ledger.placements[input.agentId] ??= {
-        id: randomUUID(),
-        root: `${base(record)}/agents/${input.agentId}`,
-        cwd: `${base(record)}/agents/${input.agentId}`,
-      };
+      const agentHome = input.agentId
+        ? `${base(record)}/agents/${input.agentId}`
+        : `${base(record)}/probes/${input.probeId}`;
+      if (input.agentId) {
+        record.ledger.placements[input.agentId] ??= {
+          id: randomUUID(),
+          root: agentHome,
+          cwd: agentHome,
+        };
+      }
       record.ledger.placements[input.sessionKey] ??= {
         id: randomUUID(),
-        root: `${base(record)}/agents/${input.agentId}`,
+        root: agentHome,
         cwd: input.probeId
           ? `${base(record)}/probes/${input.probeId}`
-          : `${base(record)}/agents/${input.agentId}`,
+          : agentHome,
       };
       return { record: structuredClone(record), owner: structuredClone(owner) };
     });
@@ -795,7 +802,7 @@ finally:
     },
   ) {
     const { record, owner } = await scoped(input);
-    if (!owner.agentId || owner.phase !== "active")
+    if (owner.phase !== "active" || (!owner.agentId && input.projectId))
       throw new ComputerError("conflict", "Workspace owner is not active");
     const placement = record.ledger.placements[owner.sessionKey!]!;
     if (!input.projectId)
@@ -976,7 +983,7 @@ finally:
     admit,
     admitProbe(
       input: Scope & {
-        agentId: string;
+        agentId?: string;
         probeId: string;
         idleTimeoutMs: number;
       },
diff --git a/server/src/services/computer-environment-driver.ts b/server/src/services/computer-environment-driver.ts
index 9a65627e29f..fd1e0ef8dcd 100644
--- a/server/src/services/computer-environment-driver.ts
+++ b/server/src/services/computer-environment-driver.ts
@@ -45,13 +45,13 @@ export function createComputerEnvironmentDriver(db: Db): EnvironmentRuntimeDrive
     driver: "computer",
     async acquireRunLease(input) {
       if (!(await instanceSettingsService(db).getExperimental()).enableBoatEnvironments) throw new Error("boat_environments_disabled");
-      if (!input.agentId) throw new Error("computer_agent_required");
+      if (input.heartbeatRunId && !input.agentId) throw new Error("computer_agent_required");
       const idleTimeoutMs = resolvePaperclipRunnerIdleTimeoutMs(input.environment.config.runnerIdleTimeoutMs);
       const binding = input.heartbeatRunId ? await computers.admit({ companyId: input.companyId, environmentId: input.environment.id,
-        agentId: input.agentId, runId: input.heartbeatRunId, idleTimeoutMs,
+        agentId: input.agentId ?? undefined, runId: input.heartbeatRunId, idleTimeoutMs,
         sessionKey: createHash("sha256").update(JSON.stringify([input.agentId, input.executionWorkspaceId ?? input.issueId, input.adapterType, input.executionConfigurationKey])).digest("hex") })
         : await computers.admitProbe({ companyId: input.companyId, environmentId: input.environment.id,
-          agentId: input.agentId, probeId: randomUUID(), idleTimeoutMs });
+          agentId: input.agentId ?? undefined, probeId: randomUUID(), idleTimeoutMs });
       try {
         // The durable owner advanced generation; prior retained bookkeeping no
         // longer owns the process and must not be reaped as an allocation.