diff --git a/docs/status-data-contract.md b/docs/status-data-contract.md
index 568a4f2ca6..22f291deb4 100644
--- a/docs/status-data-contract.md
+++ b/docs/status-data-contract.md
@@ -1833,6 +1833,23 @@ It mirrors the compact run index, but strips local artifact paths. UIs should
 show artifact availability with `json_exists` and `markdown_exists` instead of
 linking directly to local files.
 
+Artifact flags are fresh observations for every returned Run, not facts trusted
+from the persisted index. History collection first reads and deduplicates the
+complete index and computes quota and semantic history; only then does it check
+files for retained recent, latest-status, agent-lane and semantic-evidence rows.
+`--limit 0` does not discard old vision, owner correction or active blocked-retry
+evidence. Creating or deleting an artifact is visible on the next read even when
+the index bytes are unchanged. Full `load_index`/`load_index_snapshot` readers
+still observe every row by default. This is a caller filesystem optimization,
+independent of the Todo authority provider, not an index cache or a limit on
+decision history.
+
+文件存在性是每次读取对返回记录的实时观测，不信任索引中保存的布尔值。先用完整索引
+完成去重、额度和语义历史归约，再检查近期记录、最新状态、Agent 窗口及保留语义证据
+的文件；即使 `--limit 0`，旧愿景、用户纠偏和有效阻塞重试也不会因此丢失。索引不变时，
+文件创建／删除仍在下次读取生效；底层完整索引接口默认保留逐条检查行为。这不改变
+File／SQLite 等 Todo provider 的权威，也不限制决策历史。
+
 On the `status`, `quota should-run`, and `history` read paths, relative
 `common_runtime_root` values, relative `--runtime-root` overrides, and relative
 run-index artifact paths are resolved against the project root that owns the
diff --git a/loopx/control_plane/runtime/run_context_retention.py b/loopx/control_plane/runtime/run_context_retention.py
index 1b0149aa49..a62957fa7b 100644
--- a/loopx/control_plane/runtime/run_context_retention.py
+++ b/loopx/control_plane/runtime/run_context_retention.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from collections.abc import Callable
+from collections.abc import Callable, Iterator
 from typing import Any
 
 from ..quota.blocked_retry import active_turn_retry_for_run
@@ -232,6 +232,23 @@ def goal_semantic_history_from_runs(
     return semantic_history
 
 
+def iter_goal_semantic_history_runs(value: dict[str, Any]) -> Iterator[dict[str, Any]]:
+    """Enumerate retained Run references without reselecting or limiting history.
+
+    The filesystem adapter uses this shape-owned traversal to observe artifacts
+    after semantic reduction, including evidence outside the recent-run window.
+    """
+    for context in value.get("agents", []):
+        for field in SEMANTIC_CONTEXT_RUN_FIELDS:
+            run = context.get(field)
+            if isinstance(run, dict):
+                yield run
+    yield from value.get("active_blocked_retry_runs", [])
+    correction = value.get("latest_owner_correction_run")
+    if isinstance(correction, dict):
+        yield correction
+
+
 def compact_goal_semantic_history(
     value: Any,
     *,
diff --git a/loopx/history.py b/loopx/history.py
index 7c44802ab5..6dba847635 100644
--- a/loopx/history.py
+++ b/loopx/history.py
@@ -3,10 +3,10 @@
 import hashlib
 import json
 from contextlib import nullcontext
-from collections.abc import Callable
+from collections.abc import Callable, Iterable
 from dataclasses import dataclass
 from heapq import merge
-from itertools import islice
+from itertools import chain, islice
 from pathlib import Path
 from typing import Any
 
@@ -35,6 +35,7 @@
 )
 from .control_plane.runtime.run_context_retention import (
     goal_semantic_history_from_runs,
+    iter_goal_semantic_history_runs,
     latest_runs_with_agent_context,
 )
 from .control_plane.runtime.run_index_duplicates import (
@@ -229,11 +230,30 @@ def _indexed_artifact_exists(value: Any, *, artifact_root: Path | None) -> bool:
     return path.exists()
 
 
+def _observe_run_artifacts(
+    records: Iterable[dict[str, Any]], *, artifact_root: Path | None,
+) -> None:
+    """Fresh request-local observations, shared by full and selected reads."""
+    observed: dict[str, bool] = {}
+    for record in records:
+        for source, target in (("json_path", "json_exists"), ("markdown_path", "markdown_exists")):
+            path = str(record.get(source) or "").strip()
+            if path not in observed:
+                observed[path] = _indexed_artifact_exists(path, artifact_root=artifact_root)
+            record[target] = observed[path]
+
+
 def load_index_snapshot(
     path: Path,
     *,
     artifact_root: Path | None = None,
+    include_artifact_status: bool = True,
 ) -> RunIndexSnapshot:
+    """Decode the complete index; derived artifact status is optional internally.
+
+    Full readers keep fresh status by default. History collection defers only
+    filesystem observation until its complete semantic selection is known.
+    """
     try:
         stream = path.open("rb")
     except FileNotFoundError:
@@ -241,20 +261,9 @@ def load_index_snapshot(
 
     records: list[dict[str, Any]] = []
     positions: dict[tuple[str, str, str], int] = {}
-    artifact_exists: dict[tuple[str, str], bool] = {}
     raw_count = 0
     digest = hashlib.sha256()
 
-    def artifact_is_present(value: Any) -> bool:
-        text = str(value or "").strip()
-        cache_key = (text, str(artifact_root or ""))
-        if cache_key not in artifact_exists:
-            artifact_exists[cache_key] = _indexed_artifact_exists(
-                value,
-                artifact_root=artifact_root,
-            )
-        return artifact_exists[cache_key]
-
     with stream:
         for encoded_line in stream:
             digest.update(encoded_line)
@@ -275,13 +284,16 @@ def artifact_is_present(value: Any) -> bool:
                 str(item.get("markdown_path") or ""),
             )
             item = dict(item)
-            item["json_exists"] = artifact_is_present(item.get("json_path"))
-            item["markdown_exists"] = artifact_is_present(item.get("markdown_path"))
+            # These are observations, never persisted index authority.
+            item.pop("json_exists", None)
+            item.pop("markdown_exists", None)
             if key in positions:
                 records[positions[key]].update(item)
             else:
                 positions[key] = len(records)
                 records.append(item)
+    if include_artifact_status:
+        _observe_run_artifacts(records, artifact_root=artifact_root)
     return RunIndexSnapshot(
         records=records,
         raw_count=raw_count,
@@ -365,7 +377,7 @@ def collect_history(
         index_path = runtime_root / "goals" / current_goal_id / "runs" / "index.jsonl"
         index_snapshot = load_index_snapshot(
             index_path,
-            artifact_root=registry_project_root(registry_path),
+            include_artifact_status=False,
         )
         runs = index_snapshot.records
         raw_count = index_snapshot.raw_count
@@ -433,6 +445,18 @@ def collect_history(
             ),
             "semantic_history": goal_semantic_history_from_runs(runs),
         }
+        # Reduce the full index first. Old semantic evidence and lane windows
+        # may survive outside --limit; every returned Run still needs fresh
+        # flags. These references also cover the global recent_runs window.
+        status_run = goal_record["latest_status_run"]
+        _observe_run_artifacts(
+            chain(
+                goal_record["latest_runs"],
+                [status_run] if status_run is not None else [],
+                iter_goal_semantic_history_runs(goal_record["semantic_history"]),
+            ),
+            artifact_root=registry_project_root(registry_path),
+        )
         if registry_member:
             for field in REGISTRY_STATUS_FIELDS:
                 if meta.get(field):
diff --git a/loopx/semantics/project_registry_io_manifest_v1.json b/loopx/semantics/project_registry_io_manifest_v1.json
index 09c271ee70..346264a947 100644
--- a/loopx/semantics/project_registry_io_manifest_v1.json
+++ b/loopx/semantics/project_registry_io_manifest_v1.json
@@ -1735,7 +1735,7 @@
     },
     {
       "site": "loopx/history.py::<module>.collect_history::codec_read:load_registry#1",
-      "line": 329,
+      "line": 341,
       "column": 20,
       "kind": "codec_read",
       "api": "load_registry",
@@ -1743,7 +1743,7 @@
     },
     {
       "site": "loopx/history.py::<module>.inspect_index_duplicates::codec_read:load_registry#1",
-      "line": 573,
+      "line": 597,
       "column": 16,
       "kind": "codec_read",
       "api": "load_registry",
@@ -1751,7 +1751,7 @@
     },
     {
       "site": "loopx/history.py::<module>.rebuild_index_artifact_collisions::codec_read:load_registry#1",
-      "line": 787,
+      "line": 811,
       "column": 16,
       "kind": "codec_read",
       "api": "load_registry",
@@ -1759,7 +1759,7 @@
     },
     {
       "site": "loopx/history.py::<module>.repair_index_duplicates::codec_read:load_registry#1",
-      "line": 677,
+      "line": 701,
       "column": 16,
       "kind": "codec_read",
       "api": "load_registry",
diff --git a/tests/test_history_artifact_observation.py b/tests/test_history_artifact_observation.py
new file mode 100644
index 0000000000..4f67c8d6d3
--- /dev/null
+++ b/tests/test_history_artifact_observation.py
@@ -0,0 +1,179 @@
+"""History retains control evidence without probing every discarded artifact."""
+from __future__ import annotations
+
+import hashlib
+import json
+import subprocess
+import sys
+from datetime import datetime, timedelta, timezone
+
+import pytest
+
+import loopx.history as history_module
+from loopx.history import collect_history, load_index_snapshot
+
+
+@pytest.fixture
+def history_case(tmp_path, monkeypatch):
+    registry = tmp_path / "registry.json"
+    registry.write_text("{}\n")
+    runtime = tmp_path / "runtime"
+    index = runtime / "goals" / "example" / "runs" / "index.jsonl"
+    index.parent.mkdir(parents=True)
+    artifacts = tmp_path / "artifacts"
+    artifacts.mkdir()
+    start = datetime(2026, 9, 1, tzinfo=timezone.utc)
+    now = start + timedelta(seconds=1001)
+    monkeypatch.setattr(
+        "loopx.control_plane.runtime.run_context_retention.now_utc_iso",
+        lambda: now.isoformat(),
+    )
+    rows = []
+    for n in range(1000):
+        rows.append({
+            "generated_at": (start + timedelta(seconds=n)).isoformat(),
+            "run_id": f"run-{n}", "classification": "progress",
+            "agent_id": "worker", "json_path": f"artifacts/{n}.json",
+            "markdown_path": f"artifacts/{n}.md",
+            # Persisted booleans are deliberately wrong: each read observes files.
+            "json_exists": True, "markdown_exists": True,
+        })
+    rows[0]["agent_vision"] = {"agent_id": "worker", "revision": "retained"}
+    rows[1]["human_reward"] = {"decision": "revise", "reason_summary": "Keep evidence"}
+    rows[990].update({
+        "todo_id": "todo_blocked_work", "turn_instance_id": "turn-1",
+        "delivery_outcome": "outcome_gap",
+        "progress_observation": {"result_class": "blocked"},
+        "blocked_retry": {
+            "schema_version": "quota_blocked_retry_v0", "source": "turn_settlement",
+            "todo_id": "todo_blocked_work", "observed_at": rows[990]["generated_at"],
+            "due_at": (start + timedelta(seconds=1290)).isoformat(),
+            "resume_when": f"resume_at:{(start + timedelta(seconds=1290)).isoformat()}",
+        },
+    })
+    rows[995]["agent_id"] = "quiet-worker"
+    # Recent neutral records must not hide the latest status-relevant run.
+    rows[999]["classification"] = "quota_slot_spent"
+    rows[998]["classification"] = "quota_slot_spent"
+    # Last duplicate replaces only supplied fields, without another unique Run.
+    duplicate = {**rows[0], "annotation": "merged duplicate"}
+    index.write_text("\n".join(json.dumps(row) for row in [*rows, duplicate]) + "\nnot-json\n[]\n\n")
+    for n in (0, 1, 990, 995, 997, 999):
+        (artifacts / f"{n}.json").write_text("{}\n")
+    return registry, runtime, index, artifacts
+
+
+def _collect(case, *, limit=1, agent_lane_id=None):
+    registry, runtime, _, _ = case
+    return collect_history(registry_path=registry, runtime_root=runtime,
+                           goal_id="example", limit=limit, agent_lane_id=agent_lane_id)
+
+
+@pytest.mark.parametrize("limit", [0, 1, 3])
+def test_history_observes_retained_evidence_after_full_reduction(history_case, monkeypatch, limit):
+    _, _, index, _ = history_case
+    calls = []
+    original = history_module._indexed_artifact_exists
+
+    def observe(value, *, artifact_root):
+        calls.append(value)
+        return original(value, artifact_root=artifact_root)
+
+    monkeypatch.setattr(history_module, "_indexed_artifact_exists", observe)
+    result = _collect(history_case, limit=limit)
+    goal = result["goals"][0]
+    assert result["run_count"] == goal["unique_runs"] == 1000
+    assert goal["raw_index_records"] == 1003
+    assert goal["index_digest"] == f"sha256:{hashlib.sha256(index.read_bytes()).hexdigest()}"
+    assert len(result["runs"]) == len(goal["latest_runs"]) == limit
+    semantic = goal["semantic_history"]
+    vision = semantic["agents"][0]["latest_agent_vision_run"]
+    correction = semantic["latest_owner_correction_run"]
+    retry = semantic["active_blocked_retry_runs"][0]
+    assert vision["run_id"] == "run-0"
+    assert vision["annotation"] == "merged duplicate"
+    assert correction["run_id"] == "run-1"
+    assert retry["run_id"] == "run-990"
+    assert goal["latest_status_run"]["run_id"] == "run-997"
+    for row in [vision, correction, retry, goal["latest_status_run"]]:
+        assert row["json_exists"] is True
+        assert row["markdown_exists"] is False
+    # Counts depend on retained output, never the 1,000-row historical population.
+    expected = {0, 1, 990, 997, *range(1000 - limit, 1000)}
+    assert set(calls) == {f"artifacts/{n}.{ext}" for n in expected for ext in ("json", "md")}
+    assert len(calls) == len(set(calls))
+
+
+def test_lane_window_artifacts_remain_observed(history_case):
+    result = _collect(history_case, agent_lane_id="quiet-worker")
+    runs = result["goals"][0]["latest_runs"]
+    assert [run["run_id"] for run in runs] == ["run-999", "run-995"]
+    assert all(run["json_exists"] and not run["markdown_exists"] for run in runs)
+
+
+def test_unchanged_index_does_not_cache_artifact_existence(history_case):
+    _, _, index, artifacts = history_case
+    before = index.read_bytes()
+    initial = _collect(history_case)
+    assert initial["runs"][0]["json_exists"] is True
+    assert initial["runs"][0]["markdown_exists"] is False
+    (artifacts / "999.json").unlink()
+    (artifacts / "999.md").write_text("# Delivered\n")
+    (artifacts / "0.json").unlink()
+    reread = _collect(history_case)
+    assert reread["runs"][0]["json_exists"] is False
+    assert reread["runs"][0]["markdown_exists"] is True
+    assert reread["goals"][0]["semantic_history"]["agents"][0]["latest_agent_vision_run"]["json_exists"] is False
+    assert index.read_bytes() == before
+    assert reread["goals"][0]["index_digest"] == initial["goals"][0]["index_digest"]
+
+
+def test_full_index_reader_still_observes_every_row(history_case):
+    registry, _, index, artifacts = history_case
+    (artifacts / "500.md").write_text("# Older artifact\n")
+    (artifacts / "501.json").symlink_to(artifacts / "absent.json")
+    snapshot = load_index_snapshot(index, artifact_root=registry.parent)
+    assert len(snapshot.records) == 1000
+    assert snapshot.records[500]["markdown_exists"] is True
+    assert snapshot.records[501]["json_exists"] is False
+    assert snapshot.records[502]["json_exists"] is False
+
+
+@pytest.mark.parametrize("provider", ["file", "sqlite"])
+def test_public_history_and_status_keep_artifacts_with_canonical_todos(history_case, monkeypatch, tmp_path, provider):
+    from tests.control_plane.canonical_authority_fixture import (
+        initialize_canonical_authority, isolate_sqlite_runtime,
+    )
+    from loopx.control_plane.coordination.runtime_shadow import build_todo_runtime_shadow_projection
+    from loopx.control_plane.effect_runtime import restart_effect_runtime
+    from loopx.control_plane.testing.canary_harness import write_fixture_registry
+
+    isolate_sqlite_runtime(tmp_path, monkeypatch)
+    registry, runtime, _, _ = history_case
+    state = tmp_path / "state.md"
+    state.write_text("---\nstatus: active\n---\n# Example\n\n## Agent Todo\n")
+    write_fixture_registry(project=tmp_path, registry_path=registry, runtime_root=runtime,
+                           goal_id="example", domain="engineering", state_file=str(state),
+                           adapter_kind="generic_project_goal_v0")
+    initialize_canonical_authority(
+        runtime, "example", build_todo_runtime_shadow_projection(goal_id="example", todos=[]),
+        state_path=state, provider=provider,
+    )
+    try:
+        for command in ("history", "status"):
+            result = subprocess.run(
+                [sys.executable, "-m", "loopx.entrypoint", "--registry", str(registry),
+                 "--runtime-root", str(runtime), "--format", "json", command,
+                 "--goal-id", "example", "--limit", "1"],
+                capture_output=True, text=True, timeout=60,
+            )
+            assert result.returncode == 0, result.stdout + result.stderr
+            payload = json.loads(result.stdout)
+            history = payload if command == "history" else payload["run_history"]
+            goal = history["goals"][0]
+            assert goal["unique_runs"] == 1000
+            assert goal["latest_status_run"]["run_id"] == "run-997"
+            assert goal["latest_status_run"]["json_exists"] is True
+            assert goal["latest_status_run"]["markdown_exists"] is False
+    finally:
+        restart_effect_runtime()