diff --git a/doc/evals.md b/doc/evals.md
index 499d29278ce..0ba2b13d203 100644
--- a/doc/evals.md
+++ b/doc/evals.md
@@ -60,6 +60,11 @@ harness are under `tests/runner-e2e`; the package scripts are `test:e2e:runner`,
 the server and embedded database, creates the company/agent/task through the
 real APIs, drives Chromium, and invokes the selected local or Daytona runner.
 
+The explicit-only `daytona-journal-continuity` Product E2E cell exercises
+continuation after ordinary tool output grows the durable control-plane journal
+past two MiB. Its size oracle is read-only and retains only byte counts; see the
+[Product E2E fixture](../tests/runner-e2e/README.md).
+
 The explicit-only `agent-chat-hardening` Product E2E suite covers native chat
 recovery, hiring, status evidence, and review handoff on local and selected warm
 Daytona paths. Its [fixture contract](../tests/runner-e2e/README.md) distinguishes
diff --git a/tests/runner-e2e/README.md b/tests/runner-e2e/README.md
index 893e4b3a8a5..9e7168dda25 100644
--- a/tests/runner-e2e/README.md
+++ b/tests/runner-e2e/README.md
@@ -83,7 +83,7 @@ pnpm test:e2e:runner -- --suite daytona-warm-continuity
 pnpm test:e2e:runner -- --all
 ```
 
-The catalog contains thirteen suites, including the explicit-only everyday and
+The catalog contains fourteen suites, including the explicit-only everyday and
 [lifecycle baseline](LIFECYCLE-BASELINE.md) suites. The latter adds 46 real-provider
 cells pairing narrative variants and exercising durable lifecycle boundaries;
 it is excluded from `--all`. `core-compatibility` (**Core Runner
@@ -134,6 +134,16 @@ runner instance, PID, and process-start identity. Each turn is bounded to ten
 minutes, the cell to thirty minutes, and cleanup explicitly deletes the
 sandbox rather than waiting for Daytona's idle timeout.
 
+`daytona-journal-continuity` is one explicit-only native Codex cell. Select
+`daytona-journal-continuity.runner-codex.daytona.large-journal-three-turn`.
+It reuses the three-turn warm workflow after streaming four MiB of synthetic
+command output through the real provider. Before the first browser follow-up,
+a read-only controller journal oracle requires the exact completed run's journal
+to exceed two MiB. Only byte counts enter evidence. No runner state or database
+is injected or modified. The usual workspace, sandbox, provider, process,
+three-run, screenshot, timeout, billing, and cleanup assertions remain required;
+`--all` excludes this stress case.
+
 `agent-chat` (**Persistent Agent Chat**) has eight workflows on `legacy-codex`,
 `legacy-claude`, `runner-codex`, and `runner-acpx-claude`: **28 local cells**.
 They cover continuity across server restart, fresh context after `/new`,
diff --git a/tests/runner-e2e/catalog.test.ts b/tests/runner-e2e/catalog.test.ts
index 6d3504082e8..a3bad4bdf87 100644
--- a/tests/runner-e2e/catalog.test.ts
+++ b/tests/runner-e2e/catalog.test.ts
@@ -13,6 +13,7 @@ import {
   runnerSuites,
   runnerTasks,
   daytonaWarmContinuityTask,
+  daytonaLargeJournalTask,
   daytonaWarmEnvironment,
   isImmutableDaytonaImage,
   suiteDefinitionHash,
@@ -71,10 +72,10 @@ describe("runner E2E catalog", () => {
     expect(localIntegrityTasks).toHaveLength(2);
     expect(openRouterBreadthTasks).toHaveLength(3);
     expect(runnerSuites.map((suite) => suite.expectedMatrixSize)).toEqual([
-      8, 46, 23, 47, 52, 28, 18, 6, 6, 42, 14, 10, 2,
+      8, 46, 23, 47, 52, 28, 18, 6, 6, 42, 14, 10, 2, 1,
     ]);
-    expect(validateRunnerCatalog()).toHaveLength(302);
-    expect(new Set(runnerMatrix.map((entry) => entry.id)).size).toBe(302);
+    expect(validateRunnerCatalog()).toHaveLength(303);
+    expect(new Set(runnerMatrix.map((entry) => entry.id)).size).toBe(303);
     expect(
       runnerMatrix.filter((entry) => entry.suite.id === "core-compatibility"),
     ).toHaveLength(42);
@@ -186,6 +187,18 @@ describe("runner E2E catalog", () => {
     ).not.toBe(suiteDefinitionHash(suite));
   });
 
+  it("keeps large-journal stress explicit-only and uses the ordinary warm workflow", () => {
+    const suite = runnerSuites.find((candidate) => candidate.id === "daytona-journal-continuity")!;
+    expect(suite.manualOnly).toBe(true);
+    expect(suite.expectedMatrixSize).toBe(1);
+    expect(suite.profiles.map((profile) => profile.id)).toEqual(["runner-codex"]);
+    expect(daytonaLargeJournalTask.flow).toBe("warm_three_turn");
+    expect(daytonaLargeJournalTask.buildPrompt("nonce")).toContain("range(64)");
+    expect(daytonaLargeJournalTask.buildFollowupMessages!("nonce")).toEqual(daytonaWarmContinuityTask.buildFollowupMessages!("nonce"));
+    expect(selectRunnerExecutions(parseRunnerSelectors(["--all"]))
+      .some((cell) => cell.suite.id === suite.id)).toBe(false);
+  });
+
   it("derives the qualified local native OpenCode profiles from the ranked snapshot", () => {
     expect(openRouterBreadthExcludedModelIds).toEqual(["xiaomi/mimo-v2.5"]);
     expect(openRouterBreadthExcludedExecutionIds).toEqual([
diff --git a/tests/runner-e2e/catalog.ts b/tests/runner-e2e/catalog.ts
index f22fd9b8bf2..e64ca6ec0dc 100644
--- a/tests/runner-e2e/catalog.ts
+++ b/tests/runner-e2e/catalog.ts
@@ -874,6 +874,18 @@ export const daytonaWarmContinuityTask: RunnerTaskFixture = {
   },
 };
 
+export const daytonaLargeJournalTask: RunnerTaskFixture = {
+  ...daytonaWarmContinuityTask,
+  id: "large-journal-three-turn",
+  label: "Large journal three-turn workspace continuity",
+  buildTitle: (nonce) => `Runner E2E large journal continuity ${nonce}`,
+  buildPrompt: (nonce) => [
+    "First exercise ordinary command-output streaming with this bounded diagnostic. Execute this Python command exactly once, allowing it to print all 64 chunks. Do not redirect, suppress, pipe, or summarize its stdout; the transport must receive the output. The repeated text is synthetic fixture data and needs no analysis. Wait for the command to exit successfully before continuing.",
+    `python3 -c 'import sys,time; [(sys.stdout.write("journal-continuity-" + "x" * 65500 + "\\n"), sys.stdout.flush(), time.sleep(0.05)) for _ in range(64)]'`,
+    warmTurnInstructions(1, nonce),
+  ].join("\n"),
+};
+
 const codexContinuityProfiles = runnerProfiles.filter((profile) =>
   ["legacy-codex", "runner-codex"].includes(profile.id),
 );
@@ -1053,6 +1065,18 @@ export const runnerSuites: readonly RunnerSuiteFixture[] = [
     tasks: [daytonaWarmContinuityTask],
     expectedMatrixSize: 2,
   },
+  {
+    id: "daytona-journal-continuity",
+    label: "Daytona Large Journal Continuity",
+    manualOnly: true,
+    description: "Continue the same native session after real tool output grows its durable journal beyond 2 MiB.",
+    groups: ["daytona", "warm"],
+    profiles: codexContinuityProfiles.filter((profile) => profile.id === "runner-codex"),
+    environments: [daytonaWarmEnvironment],
+    tasks: [daytonaLargeJournalTask],
+    expectedMatrixSize: 1,
+    definitionMetadata: { version: 1, journalMinimumBytes: 2 * 1024 * 1024, outputChunks: 64, scheduling: "explicit-only" },
+  },
 ] as const;
 
 export function suiteDefinitionHash(suite: RunnerSuiteFixture) {
@@ -1169,6 +1193,7 @@ export function validateRunnerCatalog(): MatrixExecution[] {
     ...localIntegrityTasks,
     ...openRouterBreadthTasks,
     daytonaWarmContinuityTask,
+    daytonaLargeJournalTask,
   ];
   for (const [label, values] of [
     ["suite", runnerSuites],
diff --git a/tests/runner-e2e/journal-evidence.test.ts b/tests/runner-e2e/journal-evidence.test.ts
new file mode 100644
index 00000000000..38e56f85d18
--- /dev/null
+++ b/tests/runner-e2e/journal-evidence.test.ts
@@ -0,0 +1,26 @@
+import { mkdtemp, mkdir, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+import { largeJournalEvidence } from "./journal-evidence.js";
+
+describe("large journal boundary evidence", () => {
+  it("requires one correctly owned journal over the boundary and returns only sizes", async () => {
+    const root = await mkdtemp(path.join(tmpdir(), "journal-evidence-"));
+    const directory = path.join(root, "a".repeat(64), "control-plane");
+    await mkdir(directory, { recursive: true });
+    const filename = path.join(directory, "control-plane-state.json");
+    const state = { schema: "paperclip.runner.durable.control-plane-state.v1", identity: { runId: "expected-run" }, commands: [] };
+    try {
+      await writeFile(filename, JSON.stringify(state));
+      await expect(largeJournalEvidence({ stateRoot: root, runId: "expected-run", minimumBytes: 1024 })).rejects.toThrow("boundary not reached");
+      await writeFile(filename, JSON.stringify({ ...state, commands: [{ payload: "x".repeat(2048) }] }));
+      const evidence = await largeJournalEvidence({ stateRoot: root, runId: "expected-run", minimumBytes: 1024 });
+      expect(Object.keys(evidence)).toEqual(["journalBytes", "minimumBytes"]);
+      expect(evidence.journalBytes).toBeGreaterThan(2048);
+      await expect(largeJournalEvidence({ stateRoot: root, runId: "another-run", minimumBytes: 1024 })).rejects.toThrow("boundary not reached");
+    } finally {
+      await rm(root, { recursive: true, force: true });
+    }
+  });
+});
diff --git a/tests/runner-e2e/journal-evidence.ts b/tests/runner-e2e/journal-evidence.ts
new file mode 100644
index 00000000000..770045489a0
--- /dev/null
+++ b/tests/runner-e2e/journal-evidence.ts
@@ -0,0 +1,30 @@
+import { lstat, readdir, readFile } from "node:fs/promises";
+import path from "node:path";
+// The fixture reads bounded private evidence independently of production admission.
+const MAX_JOURNAL_EVIDENCE_BYTES = 192 * 1024 * 1024;
+
+/** Read-only size oracle; retained journal contents never enter public evidence. */
+export async function largeJournalEvidence(input: {
+  stateRoot: string;
+  runId: string;
+  minimumBytes: number;
+}): Promise<{ journalBytes: number; minimumBytes: number }> {
+  const matches: number[] = [];
+  for (const entry of await readdir(input.stateRoot, { withFileTypes: true })) {
+    if (!entry.isDirectory() || !/^[a-f0-9]{64}$/.test(entry.name)) continue;
+    const filename = path.join(input.stateRoot, entry.name, "control-plane", "control-plane-state.json");
+    const metadata = await lstat(filename).catch(() => null);
+    if (!metadata?.isFile() || metadata.size > MAX_JOURNAL_EVIDENCE_BYTES) continue;
+    const state = JSON.parse(await readFile(filename, "utf8")) as {
+      schema?: string;
+      identity?: { runId?: string };
+    };
+    if (state.schema === "paperclip.runner.durable.control-plane-state.v1" && state.identity?.runId === input.runId) {
+      matches.push(metadata.size);
+    }
+  }
+  if (matches.length !== 1 || matches[0]! <= input.minimumBytes) {
+    throw new Error(`Large-journal boundary not reached: expected one matching journal above ${input.minimumBytes} bytes; observed ${JSON.stringify(matches)}`);
+  }
+  return { journalBytes: matches[0]!, minimumBytes: input.minimumBytes };
+}
diff --git a/tests/runner-e2e/runner.spec.ts b/tests/runner-e2e/runner.spec.ts
index 19923ae6f3a..1a6179e1666 100644
--- a/tests/runner-e2e/runner.spec.ts
+++ b/tests/runner-e2e/runner.spec.ts
@@ -1,3 +1,4 @@
+import { largeJournalEvidence } from "./journal-evidence.js";
 import { observeBrowserBootstrap } from "./browser-bootstrap-diagnostics.js";
 import { runAccountingFlow } from "./accounting-flow.js";
 import type { Issue } from "../../packages/shared/src/types/issue.js";
@@ -1545,7 +1546,18 @@ for (const execution of executions) {
               `Warm turn ${completedTurn} replaced its Daytona sandbox`,
             );
           }
+          const journalEvidence = execution.suite.id === "daytona-journal-continuity" && completedTurn === 1
+            ? await largeJournalEvidence({
+                stateRoot: path.join(process.env.PAPERCLIP_HOME!, "instances", process.env.PAPERCLIP_INSTANCE_ID!, "runtime", "paperclip-runner", "durable-sessions"),
+                runId: chronologicalRuns.at(-1)!.id,
+                minimumBytes: 2 * 1024 * 1024,
+              })
+            : undefined;
+          if (journalEvidence) {
+            await writeSanitizedJson(snapshotsDir, "large-journal-boundary.json", journalEvidence, secrets);
+          }
           turnEvidence.push({
+            ...(journalEvidence ? { journalEvidence } : {}),
             turn: completedTurn,
             issue: waitingState.currentIssue,
             run: chronologicalRuns.at(-1),