diff --git a/backend/AGENTS.md b/backend/AGENTS.md
index edb2e81977..46f6aa0296 100644
--- a/backend/AGENTS.md
+++ b/backend/AGENTS.md
@@ -43,6 +43,9 @@ vars; `summarize` and pytest are offline. See its README for the protocol.
 Benchmarks in `scripts/benchmark/` must be standalone and reproducible. Import
 production functions; never duplicate them or introduce an alternative runtime.
 
+`scripts/benchmark/context_memory_comparison/` runs an offline Gateway with
+SQLite. Keep original- and fresh-thread results separate.
+
 Sandbox benchmarks reuse production lifecycle. Reject negative/NaN timing values
 before provider creation, export no secrets, and fail on final cleanup errors.
 See the sandbox benchmark README for supported options and tests.
diff --git a/backend/scripts/benchmark/context_memory_comparison/README.md b/backend/scripts/benchmark/context_memory_comparison/README.md
new file mode 100644
index 0000000000..e43b406be1
--- /dev/null
+++ b/backend/scripts/benchmark/context_memory_comparison/README.md
@@ -0,0 +1,34 @@
+# Offline memory and project context comparison
+
+This synthetic benchmark for [#7884](https://github.com/bytedance/deer-flow/issues/7884)
+starts a disposable Gateway in process with SQLite. It creates projects, shelf
+documents, threads and memory through the real API. A fixed model records the
+messages passed to it, and DeerMem receives scripted extraction responses.
+
+Run this command from the backend directory of a Git checkout.
+
+```sh
+uv run python -m scripts.benchmark.context_memory_comparison run-offline --output-dir /tmp/context-memory
+```
+
+The command runs the committed fixtures and writes one `report.json` with
+the source revision, benchmark and fixture hashes, and the observations below.
+
+- Two projects and an unassigned thread must see only their own context and
+  the default memory bucket. A custom agent must see its own memory bucket.
+  The project-only check requires a successful update with exactly one fact
+  rejected for scope (`scope_rejections` in the report). The fact must also be
+  absent from default memory and from the other thread's prompt.
+- Replacement and deletion are observed in the store, in the original thread's
+  next turn, and in a fresh thread. A first-turn canary verifies checkpoint reuse.
+  The fresh thread is a control. If the original thread keeps a memory block
+  from its checkpoint, the report records
+  the stale fact and marks that check failed.
+- Each recorded turn includes character-based token estimates for the
+  `<memory>`, `<project>` and `<documents>` blocks in its actual model request.
+  The default and custom-agent observations identify the memory bucket being
+  measured. These are estimates for the injected blocks.
+
+The exit code is 0 when all behavioral checks pass and 1 when any fail.
+The benchmark uses synthetic data and fixed model responses. Gateway state is
+temporary, and the report contains canary IDs and counts rather than full prompts.
diff --git a/backend/scripts/benchmark/context_memory_comparison/__init__.py b/backend/scripts/benchmark/context_memory_comparison/__init__.py
new file mode 100644
index 0000000000..7ffa98d8f2
--- /dev/null
+++ b/backend/scripts/benchmark/context_memory_comparison/__init__.py
@@ -0,0 +1 @@
+"""DeerFlow Issue #7884 Offline Memory vs Project Context Comparison Benchmark."""
diff --git a/backend/scripts/benchmark/context_memory_comparison/__main__.py b/backend/scripts/benchmark/context_memory_comparison/__main__.py
new file mode 100644
index 0000000000..bfdcd0c115
--- /dev/null
+++ b/backend/scripts/benchmark/context_memory_comparison/__main__.py
@@ -0,0 +1,4 @@
+from .cli import main
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/backend/scripts/benchmark/context_memory_comparison/cli.py b/backend/scripts/benchmark/context_memory_comparison/cli.py
new file mode 100644
index 0000000000..df663d021b
--- /dev/null
+++ b/backend/scripts/benchmark/context_memory_comparison/cli.py
@@ -0,0 +1,27 @@
+from __future__ import annotations
+
+import argparse
+import json
+from collections.abc import Sequence
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+from .runner import run_offline
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description="Compare DeerMem and project context through an offline Gateway.")
+    parser.add_argument("command", choices=["run-offline"])
+    parser.add_argument("--output-dir", type=Path, required=True)
+    args = parser.parse_args(argv)
+
+    report = run_offline()
+    output_dir = args.output_dir
+    output_dir.mkdir(parents=True, exist_ok=True)
+    target = output_dir / "report.json"
+    with TemporaryDirectory(dir=output_dir) as staging:
+        path = Path(staging) / target.name
+        path.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
+        path.replace(target)
+    print(f"Wrote {target}")
+    return 0 if report["passed"] else 1
diff --git a/backend/scripts/benchmark/context_memory_comparison/manifest.json b/backend/scripts/benchmark/context_memory_comparison/manifest.json
new file mode 100644
index 0000000000..84d059e0c9
--- /dev/null
+++ b/backend/scripts/benchmark/context_memory_comparison/manifest.json
@@ -0,0 +1,28 @@
+{
+  "dataset": "context-memory-synthetic-v1",
+  "question": "Which context applies here?",
+  "thread_history_control": "BENCH-THREAD-HISTORY",
+  "default_fact": "BENCH-DEFAULT-PREFERENCE",
+  "agent": "bench-agent",
+  "agent_fact": "BENCH-AGENT-PREFERENCE",
+  "project_only_fact": "BENCH-PROJECT-ONLY-PREFERENCE",
+  "projects": {
+    "alpha": {
+      "instructions": "BENCH-ALPHA-INSTRUCTIONS",
+      "document": "BENCH-ALPHA-DOCUMENT.md"
+    },
+    "beta": {
+      "instructions": "BENCH-BETA-INSTRUCTIONS",
+      "document": "BENCH-BETA-DOCUMENT.md"
+    }
+  },
+  "invalidation": {
+    "replacement": {
+      "old": "BENCH-OLD-REPLACEMENT",
+      "new": "BENCH-NEW-REPLACEMENT"
+    },
+    "deletion": {
+      "old": "BENCH-OLD-DELETION"
+    }
+  }
+}
diff --git a/backend/scripts/benchmark/context_memory_comparison/runner.py b/backend/scripts/benchmark/context_memory_comparison/runner.py
new file mode 100644
index 0000000000..a678108de6
--- /dev/null
+++ b/backend/scripts/benchmark/context_memory_comparison/runner.py
@@ -0,0 +1,305 @@
+"""Run synthetic prompt checks through the local Gateway and real SQLite."""
+
+from __future__ import annotations
+
+import hashlib
+import json
+import os
+import re
+import subprocess
+from contextlib import chdir
+from contextvars import ContextVar
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from typing import Any, ClassVar
+from unittest.mock import patch
+
+from fastapi.testclient import TestClient
+from langchain_core.language_models import BaseChatModel
+from langchain_core.messages import AIMessage, BaseMessage, HumanMessage
+from langchain_core.outputs import ChatGeneration, ChatResult
+
+ROOT = Path(__file__).resolve().parent
+MANIFEST = ROOT / "manifest.json"
+REPLY = "Offline benchmark response."
+DAY = "2026-11-09, Monday"
+_PROJECT_SCOPE_TRACE = "benchmark-project-scope"
+_EMPTY_UPDATE = {"user": {}, "history": {}, "newFacts": [], "factsToRemove": []}
+_SCRIPTED_UPDATE: ContextVar[dict[str, Any] | None] = ContextVar("offline_memory_update", default=None)
+
+
+class OfflineModel(BaseChatModel):
+    """Capture agent requests and return fixed replies for both model roles."""
+
+    model: str
+    temperature: float = 0.0
+    requests: ClassVar[list[list[BaseMessage]]] = []
+
+    @property
+    def _llm_type(self) -> str:
+        return "context-memory-offline"
+
+    def bind_tools(self, tools, **kwargs):
+        return self
+
+    def _generate(self, messages, stop=None, run_manager=None, **kwargs) -> ChatResult:
+        if self.model == "extract":
+            content = json.dumps(_SCRIPTED_UPDATE.get() or _EMPTY_UPDATE)
+        else:
+            self.requests.append(list(messages))
+            content = REPLY
+        return ChatResult(generations=[ChatGeneration(message=AIMessage(content=content))])
+
+
+def _request(client: TestClient, method: str, path: str, **kwargs) -> dict:
+    response = client.request(method, path, **kwargs)
+    response.raise_for_status()
+    return response.json()
+
+
+def _thread(client: TestClient, project_id: str | None = None) -> str:
+    return _request(client, "POST", "/api/threads", json={"project_id": project_id})["thread_id"]
+
+
+def _prompt(client: TestClient, thread_id: str, question: str, assistant_id: str = "lead_agent") -> list[BaseMessage]:
+    OfflineModel.requests.clear()
+    result = _request(
+        client,
+        "POST",
+        f"/api/threads/{thread_id}/runs/wait",
+        json={
+            "assistant_id": assistant_id,
+            "input": {"messages": [{"role": "user", "content": question}]},
+            "config": {"configurable": {"model_name": "record", "thinking_enabled": False}},
+        },
+    )
+    messages = result.get("messages") or []
+    if len(OfflineModel.requests) != 1 or not messages or messages[-1].get("content") != REPLY:
+        raise RuntimeError("Gateway run did not complete with exactly one recorded model request")
+    return OfflineModel.requests.pop()
+
+
+def _present(text: str, canaries: set[str]) -> list[str]:
+    return sorted(canary for canary in canaries if canary in text)
+
+
+def _observe(messages: list[BaseMessage], canaries: set[str], expected: set[str]) -> dict:
+    from deerflow.agents.memory.backends.deermem.deermem.core.prompt import _count_tokens
+    from deerflow.projects.context import is_project_context_message
+
+    present = _present("\n".join(str(message.content) for message in messages), canaries)
+    blocks = {"memory": [], "project": [], "documents": []}
+    for message in messages:
+        if not isinstance(message, HumanMessage) or not isinstance(message.content, str):
+            continue
+        if message.content.startswith("<memory>"):
+            blocks["memory"].append(message.content)
+        if is_project_context_message(message):
+            for tag in ("project", "documents"):
+                blocks[tag].extend(re.findall(rf"<{tag}(?:\s[^>]*)?>.*?</{tag}>", message.content, flags=re.DOTALL))
+    return {
+        "passed": set(present) == expected,
+        "present": present,
+        "context_token_estimate": {name: sum(_count_tokens(block, use_tiktoken=False) for block in values) for name, values in blocks.items()},
+    }
+
+
+def _extract(thread_id: str, instruction: str, *, new_facts: list[dict], removals: list[dict], trace_id: str | None = None) -> bool:
+    from deerflow.agents.memory import get_memory_manager
+    from deerflow.agents.memory.backends.deermem.deermem.core.paths import DEFAULT_AGENT_BUCKET
+    from deerflow.runtime.user_context import DEFAULT_USER_ID
+
+    token = _SCRIPTED_UPDATE.set({**_EMPTY_UPDATE, "newFacts": new_facts, "factsToRemove": removals})
+    try:
+        # Execute the production write synchronously so its outcome precedes
+        # the next Gateway run. Ordinary background extractions are no-ops.
+        return get_memory_manager()._updater.update_memory(
+            [HumanMessage(content=instruction), AIMessage(content="Understood.")],
+            thread_id=thread_id,
+            user_id=DEFAULT_USER_ID,
+            agent_name=DEFAULT_AGENT_BUCKET,
+            trace_id=trace_id,
+            bypass_watermark=True,
+        )
+    finally:
+        _SCRIPTED_UPDATE.reset(token)
+
+
+def _fact(content: str) -> dict:
+    return {"content": content, "category": "preference", "confidence": 0.99}
+
+
+def _extracted_fact(content: str, scope: str) -> dict:
+    return {**_fact(content), "scope": scope, "durability": "durable", "authority": "descriptive"}
+
+
+def _scope_isolation(client: TestClient, fixture: dict, project_extraction_metrics: dict) -> dict:
+    default_fact = fixture["default_fact"]
+    agent = fixture["agent"]
+    agent_fact = fixture["agent_fact"]
+    rejected = fixture["project_only_fact"]
+    _request(client, "POST", "/api/memory/facts", json=_fact(default_fact))
+    _request(client, "POST", "/api/agents", json={"name": agent, "model": "record", "soul": "Synthetic benchmark agent."})
+    _request(client, "POST", "/api/memory/facts", params={"agent_name": agent}, json=_fact(agent_fact))
+
+    threads = {}
+    project_canaries = {}
+    for label, project in fixture["projects"].items():
+        project_id = _request(client, "POST", "/api/projects", json={"name": label, "instructions": project["instructions"]})["id"]
+        document = project["document"]
+        _request(client, "POST", f"/api/projects/{project_id}/documents", files={"file": (document, document.encode("utf-8"), "text/plain")})
+        threads[label] = _thread(client, project_id)
+        project_canaries[label] = {project["instructions"], document}
+
+    canaries = {default_fact, agent_fact, rejected}.union(*project_canaries.values())
+    question = fixture["question"]
+    observations = {label: _observe(_prompt(client, thread, question), canaries, {default_fact, *project_canaries[label]}) for label, thread in threads.items()}
+    observations["unassigned"] = _observe(_prompt(client, _thread(client), question), canaries, {default_fact})
+    observations["custom_agent"] = _observe(_prompt(client, _thread(client), question, agent), canaries, {agent_fact})
+
+    updated = _extract(
+        threads["alpha"],
+        "Apply this preference only in the current project.",
+        new_facts=[_extracted_fact(rejected, "project")],
+        removals=[],
+        trace_id=_PROJECT_SCOPE_TRACE,
+    )
+    project_fact = {"update_succeeded": updated, "passed": False}
+    if updated:
+        scope_rejections = project_extraction_metrics.get("scope_gate_rejections", {}).get("facts", {}).get("scope", 0)
+        stored = bool(_present(json.dumps(_request(client, "GET", "/api/memory")), {rejected}))
+        beta = _observe(_prompt(client, threads["beta"], question), canaries, {default_fact, *project_canaries["beta"]})
+        project_fact.update({"scope_rejections": scope_rejections, "stored": stored, "other_thread": beta, "passed": scope_rejections == 1 and not stored and beta["passed"]})
+
+    return {
+        "passed": all(turn["passed"] for turn in observations.values()) and project_fact["passed"],
+        "threads": observations,
+        "project_only_fact": project_fact,
+    }
+
+
+def _invalidation(client: TestClient, fixture: dict, case: dict) -> dict:
+    from deerflow.agents.memory.backends.deermem.deermem.core.storage import create_empty_memory
+
+    old = case["old"]
+    new = case.get("new")
+    control = fixture["default_fact"]
+    history = fixture["thread_history_control"]
+    canaries = {old, control, history}
+    after = {control}
+    removal = {"id": "superseded-fact", "scope": "user", "reason": "The user invalidated the old preference."}
+    new_facts = []
+    if new is not None:
+        canaries.add(new)
+        after.add(new)
+        removal["replacementFactIndex"] = 0
+        new_facts.append(_extracted_fact(new, "user"))
+
+    seed = create_empty_memory()
+    seed["facts"] = [
+        {**_fact(old), "id": removal["id"], "source": "synthetic"},
+        {**_fact(control), "id": "control-fact", "source": "synthetic"},
+    ]
+    _request(client, "POST", "/api/memory/import", json=seed)
+    original = _thread(client)
+    question = fixture["question"]
+    before = _observe(_prompt(client, original, f"{question} {history}"), canaries, {old, control, history})
+    updated = _extract(original, "Forget the old preference.", new_facts=new_facts, removals=[removal])
+    if not updated:
+        return {"passed": False, "update_succeeded": False, "before": before}
+
+    stored = _present(json.dumps(_request(client, "GET", "/api/memory")), canaries)
+    same = _observe(_prompt(client, original, question), canaries, after | {history})
+    fresh = _observe(_prompt(client, _thread(client), question), canaries, after)
+    return {
+        "passed": before["passed"] and set(stored) == after and same["passed"] and fresh["passed"],
+        "update_succeeded": True,
+        "before": before,
+        "stored": stored,
+        "same_thread": same,
+        "new_thread": fresh,
+    }
+
+
+def _config() -> dict:
+    return {
+        # DeerMem uses the first configured model for extraction. Runs
+        # explicitly select the recording model so these calls stay separate.
+        "models": [{"name": name, "use": f"{__name__}:OfflineModel", "model": name, "temperature": 0, "supports_tool_calling": True} for name in ("extract", "record")],
+        "sandbox": {"use": "deerflow.sandbox.local:LocalSandboxProvider"},
+        "database": {"backend": "sqlite", "sqlite_dir": "db"},
+        "run_events": {"backend": "db"},
+        "log_level": "WARNING",
+        "title": {"enabled": False},
+        "summarization": {"enabled": False},
+        "agents_api": {"enabled": True},
+        "memory": {
+            "backend_config": {
+                "token_counting": "char",
+                "retrieval_adapter": "",
+                "staleness_review_enabled": False,
+                "consolidation_enabled": False,
+            },
+        },
+        "skills": {"path": "skills"},
+    }
+
+
+def run_offline() -> dict:
+    """Use a disposable Gateway config and data directory in a standalone process."""
+    fixture_bytes = MANIFEST.read_bytes()
+    fixture = json.loads(fixture_bytes)
+    canaries = [fixture[key] for key in ("default_fact", "agent_fact", "project_only_fact", "thread_history_control")]
+    canaries.extend(value for project in fixture["projects"].values() for value in project.values())
+    canaries.extend(value for case in fixture["invalidation"].values() for value in case.values())
+    if len(set(canaries)) != len(canaries):
+        raise ValueError("Synthetic canaries must be distinct")
+
+    config_bytes = json.dumps(_config(), sort_keys=True).encode("utf-8")
+    revision = subprocess.check_output(["git", "rev-parse", "HEAD"], cwd=ROOT, text=True).strip()
+    project_extraction_metrics: dict[str, Any] = {}
+
+    def record_project_extraction(payload: dict[str, Any]) -> None:
+        # The explicit project update has its own trace. Ignore background extractions.
+        if payload.get("trace_id") == _PROJECT_SCOPE_TRACE:
+            project_extraction_metrics.update(payload)
+
+    with TemporaryDirectory(prefix="deerflow-context-memory-", ignore_cleanup_errors=True) as directory:
+        root = Path(directory).resolve()
+        (root / "config.yaml").write_bytes(config_bytes)
+        (root / "extensions.json").write_text("{}", encoding="utf-8")
+        (root / "empty.env").touch()
+        env = {key: os.environ[key] for key in ("PATH", "SYSTEMROOT", "WINDIR") if key in os.environ}
+        env.update(
+            DEER_FLOW_AUTH_DISABLED="1",
+            DEER_FLOW_HOME=str(root / "home"),
+            DEER_FLOW_PROJECT_ROOT=str(root),
+            DEER_FLOW_CONFIG_PATH=str(root / "config.yaml"),
+            DEER_FLOW_EXTENSIONS_CONFIG_PATH=str(root / "extensions.json"),
+            DEER_FLOW_ENV_FILE=str(root / "empty.env"),
+        )
+        with patch.dict(os.environ, env, clear=True), chdir(root):
+            from app.gateway.app import app
+
+            with (
+                patch("deerflow.agents.memory.manager._host_default_extraction_callback", new=record_project_extraction),
+                patch("deerflow.agents.middlewares.dynamic_context_middleware._format_current_date", return_value=DAY),
+                TestClient(app) as client,
+            ):
+                scope = _scope_isolation(client, fixture, project_extraction_metrics)
+                invalidation = {name: _invalidation(client, fixture, case) for name, case in fixture["invalidation"].items()}
+
+    return {
+        "source_revision": revision,
+        "runner_sha256": hashlib.sha256(Path(__file__).read_bytes()).hexdigest(),
+        "fixture_sha256": hashlib.sha256(fixture_bytes).hexdigest(),
+        "config_sha256": hashlib.sha256(config_bytes).hexdigest(),
+        "dataset": fixture["dataset"],
+        "prompt_path": "Gateway runs/wait to recording model",
+        "checkpoint_backend": "sqlite",
+        "token_estimate_method": "character estimate of injected blocks",
+        "date": DAY,
+        "passed": scope["passed"] and all(case["passed"] for case in invalidation.values()),
+        "scope_isolation": scope,
+        "invalidation": invalidation,
+    }
diff --git a/backend/tests/test_bench_context_memory_comparison.py b/backend/tests/test_bench_context_memory_comparison.py
new file mode 100644
index 0000000000..a9a1ce4276
--- /dev/null
+++ b/backend/tests/test_bench_context_memory_comparison.py
@@ -0,0 +1,117 @@
+"""Regression checks for the offline benchmark's actual CLI and report."""
+
+import json
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+BACKEND = Path(__file__).resolve().parents[1]
+MODULE = "scripts.benchmark.context_memory_comparison"
+MANIFEST = BACKEND / "scripts/benchmark/context_memory_comparison/manifest.json"
+
+
+def _run(tmp_path: Path, entrypoint: list[str]) -> tuple[int, dict]:
+    # Run the standalone Gateway in a fresh process. In particular, pytest's
+    # global stubs and another test's app config must not leak into this run.
+    env = {
+        **os.environ,
+        "PYTHONPATH": os.pathsep.join(str(BACKEND / path) for path in (".", "packages/harness", "packages/extension-api")),
+    }
+    result = subprocess.run(
+        [sys.executable, *entrypoint, "run-offline", "--output-dir", str(tmp_path)],
+        cwd=BACKEND,
+        env=env,
+        capture_output=True,
+        text=True,
+        timeout=60,
+    )
+    report = tmp_path / "report.json"
+    assert report.is_file(), result.stderr
+    assert {path.name for path in tmp_path.iterdir()} == {"report.json"}
+    return result.returncode, json.loads(report.read_text(encoding="utf-8"))
+
+
+def test_offline_cli_records_real_gateway_context(tmp_path: Path) -> None:
+    fixture = json.loads(MANIFEST.read_text(encoding="utf-8"))
+    code, report = _run(tmp_path, ["-m", MODULE])
+    assert report["checkpoint_backend"] == "sqlite"
+    assert report["dataset"] == fixture["dataset"]
+
+    scope = report["scope_isolation"]
+    assert scope["passed"]
+    control = fixture["default_fact"]
+    for label, project in fixture["projects"].items():
+        turn = scope["threads"][label]
+        assert set(turn["present"]) == {control, project["instructions"], project["document"]}
+        assert all(turn["context_token_estimate"][tag] > 0 for tag in ("memory", "project", "documents"))
+    for label, fact in (("unassigned", control), ("custom_agent", fixture["agent_fact"])):
+        turn = scope["threads"][label]
+        assert turn["present"] == [fact]
+        assert turn["context_token_estimate"]["memory"] > 0
+        assert turn["context_token_estimate"]["project"] == turn["context_token_estimate"]["documents"] == 0
+    rejected = scope["project_only_fact"]
+    assert rejected["update_succeeded"] and rejected["passed"]
+    assert rejected["scope_rejections"] == 1
+    assert not rejected["stored"]
+    assert fixture["project_only_fact"] not in rejected["other_thread"]["present"]
+
+    history = fixture["thread_history_control"]
+    assert set(report["invalidation"]) == {"deletion", "replacement"}
+    for name, case in report["invalidation"].items():
+        data = fixture["invalidation"][name]
+        expected = {control}
+        if "new" in data:
+            expected.add(data["new"])
+        assert case["before"]["present"] == sorted({control, data["old"], history})
+        assert case["update_succeeded"]
+        assert set(case["stored"]) == set(case["new_thread"]["present"]) == expected
+        assert history in case["same_thread"]["present"]
+        # Pin the benchmark's verdict to the captured messages so a future
+        # production invalidation fix can change the observed behavior.
+        assert case["passed"] == (set(case["same_thread"]["present"]) == expected | {history})
+    assert report["passed"] == all(case["passed"] for case in report["invalidation"].values())
+    assert code == (0 if report["passed"] else 1)
+
+
+@pytest.mark.parametrize("failure_mode", ["extraction_error", "no_scope_rejection"])
+def test_scope_isolation_requires_a_scope_rejection(tmp_path: Path, failure_mode: str) -> None:
+    driver = """
+import sys
+
+from scripts.benchmark.context_memory_comparison import runner
+from scripts.benchmark.context_memory_comparison.cli import main
+
+generate = runner.OfflineModel._generate
+failure_mode = sys.argv.pop(1)
+
+def change_project_extraction(self, *args, **kwargs):
+    update = runner._SCRIPTED_UPDATE.get()
+    if self.model == "extract" and update and any(fact["scope"] == "project" for fact in update["newFacts"]):
+        if failure_mode == "extraction_error":
+            raise OSError("Synthetic extraction failure")
+        token = runner._SCRIPTED_UPDATE.set({**update, "newFacts": []})
+        try:
+            return generate(self, *args, **kwargs)
+        finally:
+            runner._SCRIPTED_UPDATE.reset(token)
+    return generate(self, *args, **kwargs)
+
+runner.OfflineModel._generate = change_project_extraction
+raise SystemExit(main())
+"""
+    code, report = _run(tmp_path, ["-c", driver, failure_mode])
+    assert code == 1
+    scope = report["scope_isolation"]
+    assert all(turn["passed"] for turn in scope["threads"].values())
+    project_fact = scope["project_only_fact"]
+    assert not project_fact["passed"]
+    if failure_mode == "extraction_error":
+        assert not project_fact["update_succeeded"]
+    else:
+        assert project_fact["update_succeeded"]
+        assert not project_fact["stored"] and project_fact["other_thread"]["passed"]
+        assert project_fact["scope_rejections"] == 0
+    assert not scope["passed"] and not report["passed"]