diff --git a/docs/DEVELOPMENT.md b/docs/DEVELOPMENT.md
index 8a628c406..f9ec4cc93 100644
--- a/docs/DEVELOPMENT.md
+++ b/docs/DEVELOPMENT.md
@@ -875,7 +875,7 @@ wrong_citation 且 forbid_citations=true 的源码拒绝还会检查答案正文
 
 本次有界真实验收使用 `services/agent/e2e_guarded_boundary_evaluation.py`，CLI 身份参数与既有入口相同。它要求同一周期 active 和 clean checkout，并将共享增量 guard 注入 loop/judge 两个适配器，付费负探针复用 judge。增量日志固定在该周期 accounting 目录的 `dav58-increment-<identity>.json`；已存在即拒绝重放，不重置。入口将 guard 与自身的源码 hash 加入 artifact provenance。
 
-增量 guard 按已核验的 DeepSeek Flash 高峰费率，在每次 HTTP 前持久化完整模型上限包络（保守取 1,048,576 输入和 393,216 输出 tokens），不依赖本地 framing 估计。只有完整、相互一致的 usage 才将独立包络结算为高峰费用；原 ModelBudget 预留从不退款。未知 usage、异常模型/思考输出、网络或落盘失败停止全部后续调用。已核验费用加完整包络须不超过本次 USD1；可能提前停止，不能保证完整矩阵必能完成。transport 无重试，周期与 purpose 门禁同时生效。
+增量 guard 按已核验的 DeepSeek Flash 高峰费率，在每次 HTTP 前持久化完整模型上限包络（保守取 1,048,576 输入和 393,216 输出 tokens），不依赖本地 framing 估计。只有完整、相互一致的 usage 才将独立包络结算为高峰费用；原 ModelBudget 预留从不退款。未知 usage、异常模型/思考输出、网络或落盘失败停止全部后续调用。网络或读取失败回执记录 `network_error_class`：HTTPX 原生连接/读取错误与超时仅记录类型名，其他异常归为 `transport_failure`，不记录异常消息、URL 或请求内容。已核验费用加完整包络须不超过本次 USD1；可能提前停止，不能保证完整矩阵必能完成。transport 无重试，周期与 purpose 门禁同时生效。
 
 
 
@@ -956,6 +956,9 @@ This mode is recovery preparation, not formal model/Java acceptance.
 For offline preparation, `validate_recovery_sources` checks bounded source
 snapshots against an explicit attempt-to-request-body-hash crosswalk; SQL attempt
 IDs do not supply that crosswalk. Missing original mappings must not be synthesized.
+Optional guard receipt `network_error_class` accepts only `ConnectError`, `ReadError`,
+`ConnectTimeout`, `ReadTimeout` or `transport_failure`; legacy receipts may omit it.
+Other values and unknown fields are rejected; this diagnostic never settles unknown usage.
 `compile_recovery_plan` derives conditional costs from explicit approval, pricing
 and lane caps using `A + U + R - cmin + E` for a single in-flight request. Its result
 has `paid_authorized=False` and `runtime_applied=False`: caller-declared caps are
diff --git a/services/agent/data/repository_corpus_manifest.json b/services/agent/data/repository_corpus_manifest.json
index d24502ccd..a94d112e9 100644
--- a/services/agent/data/repository_corpus_manifest.json
+++ b/services/agent/data/repository_corpus_manifest.json
@@ -29,8 +29,8 @@
   },
   {
     "doc_id": "repository-development",
-    "version": "sha256-fc51f51a59ce466ed4c08135164f0f8bb914e13bad0c20e333eb85e402b92908",
-    "chunk_id": "repository-development:sha256-fc51f51a59ce466ed4c08135164f0f8bb914e13bad0c20e333eb85e402b92908:1",
+    "version": "sha256-17b79d66eafe8b4e8b3a3d9cc7a4e675ee39f7dbe4bb375f010d31bad11e6d5e",
+    "chunk_id": "repository-development:sha256-17b79d66eafe8b4e8b3a3d9cc7a4e675ee39f7dbe4bb375f010d31bad11e6d5e:1",
     "source_path": "docs/DEVELOPMENT.md",
     "access_scope": "repository-public",
     "sample_kind": "real",
diff --git a/services/agent/src/budget_binding_migration.py b/services/agent/src/budget_binding_migration.py
index c7442bb2e..83d05b7ce 100644
--- a/services/agent/src/budget_binding_migration.py
+++ b/services/agent/src/budget_binding_migration.py
@@ -460,7 +460,7 @@ def rehearse_audit_recovery(source, destination):
 _GUARD_STATE_KEYS = ("config_sha256", "continuation_run", "halted", "limit_micro_usd",
                      "pending_micro_usd", "period_identity", "policy", "receipts",
                      "settled_peak_micro_usd")
-_GUARD_RECEIPT_KEYS = ("completion_token_cap", "completion_tokens", "finished_at_utc", "lane",
+_GUARD_RECEIPT_KEYS = ("completion_token_cap", "completion_tokens", "finished_at_utc", "lane", "network_error_class",
                        "peak_micro_usd", "prompt_token_cap", "prompt_tokens", "reason",
                        "request_bytes", "request_model", "request_sha256", "reserved_micro_usd",
                        "response_model", "started_at_utc", "status", "total_tokens")
@@ -625,6 +625,11 @@ def validate_recovery_sources(sources, guard, unknown_match):
         if (not isinstance(receipt, dict) or not set(receipt) <= set(_GUARD_RECEIPT_KEYS)
                 or not isinstance(receipt.get("lane"), str)
                 or not 1 <= len(receipt["lane"]) <= _MAX_LANE_TEXT
+                or ("network_error_class" in receipt and (
+                    type(receipt["network_error_class"]) is not str
+                    or receipt["network_error_class"] not in (
+                        "ConnectError", "ReadError", "ConnectTimeout", "ReadTimeout", "transport_failure"
+                    )))
                 or (peak_micro_usd is not None and not _bounded_count(peak_micro_usd))
                 or any(not _bounded_scalar(value) for value in receipt.values())):
             raise ValueError("guard receipt declares missing or unbounded fields")
diff --git a/services/agent/src/dav58_live_guard.py b/services/agent/src/dav58_live_guard.py
index d90bf04b9..fc062feb1 100644
--- a/services/agent/src/dav58_live_guard.py
+++ b/services/agent/src/dav58_live_guard.py
@@ -311,7 +311,12 @@ async def handle_async_request(self, request):
         try:
             response = await self.inner.handle_async_request(request)
             await response.aread()
-        except BaseException:
+        except BaseException as error:
+            receipt["network_error_class"] = (
+                type(error).__name__ if type(error) in (
+                    httpx.ConnectError, httpx.ReadError, httpx.ConnectTimeout, httpx.ReadTimeout
+                ) else "transport_failure"
+            )
             self.guard.halt(receipt, "network_or_read_failure")
             raise ModelBudgetExceeded("incremental guard stopped after network failure") from None
         self.guard.finish(receipt, response)
diff --git a/services/agent/tests/test_budget_binding_migration.py b/services/agent/tests/test_budget_binding_migration.py
index 4f56fe871..572eedecc 100644
--- a/services/agent/tests/test_budget_binding_migration.py
+++ b/services/agent/tests/test_budget_binding_migration.py
@@ -463,6 +463,33 @@ def test_recovery_source_snapshot_preserves_exact_47_rows_and_unknown_guard_prov
         evidence.source_provenance_by_ledger[ids[0]]["recorded_ledger"][0] = 59
 
 
+@pytest.mark.parametrize("diagnostic", [
+    "ConnectError", "ReadError", "ConnectTimeout", "ReadTimeout", "transport_failure",
+])
+def test_recovery_source_accepts_safe_network_diagnostic_without_releasing_unknown(diagnostic):
+    sources, guard, unknown_match = _synthetic_recovery_inputs()
+    guard["state"]["receipts"][-1]["network_error_class"] = diagnostic
+    guard["source_sha256"] = _recovery_digest(guard["state"])
+
+    evidence = migration.validate_recovery_sources(sources, guard, unknown_match)
+
+    assert evidence.unknown_attempts == 1
+    assert evidence.pending_micro_usd == 786432
+    assert evidence.guard_source_sha256 == guard["source_sha256"]
+
+
+@pytest.mark.parametrize("diagnostic", [
+    "", "RuntimeError", "ReadError: secret", None, True, 1, [], {},
+])
+def test_recovery_source_rejects_invalid_network_diagnostic(diagnostic):
+    sources, guard, unknown_match = _synthetic_recovery_inputs()
+    guard["state"]["receipts"][-1]["network_error_class"] = diagnostic
+    guard["source_sha256"] = _recovery_digest(guard["state"])
+
+    with pytest.raises(ValueError, match="guard receipt"):
+        migration.validate_recovery_sources(sources, guard, unknown_match)
+
+
 def test_recovery_source_evidence_holds_no_mutable_alias_of_its_inputs():
     ids = ("a" * 32, "b" * 32)
     sources, guard, unknown_match = _synthetic_recovery_inputs()
diff --git a/services/agent/tests/test_dav58_live_guard.py b/services/agent/tests/test_dav58_live_guard.py
index 52f0b8b25..cda214a56 100644
--- a/services/agent/tests/test_dav58_live_guard.py
+++ b/services/agent/tests/test_dav58_live_guard.py
@@ -127,6 +127,38 @@ async def run():
     assert guard.state["pending_micro_usd"] == 786432
 
 
+@pytest.mark.parametrize("error,expected", [
+    (httpx.ConnectError("private-token private-request"), "ConnectError"),
+    (httpx.ReadTimeout("private-token private-request"), "ReadTimeout"),
+    (RuntimeError("private-token private-request"), "transport_failure"),
+    (type("private_token", (httpx.ConnectError,), {})("private-token private-request"), "transport_failure"),
+])
+def test_network_failure_records_safe_type_without_message_or_retry(tmp_path, error, expected):
+    requests = []
+    def handler(request):
+        requests.append(request)
+        raise error
+    guard, loop, judge = models(tmp_path, handler)
+    try:
+        async def run():
+            for model in (loop, judge):
+                with pytest.raises(ModelBudgetExceeded) as failure:
+                    await model.decide([{"role": "user", "content": "case"}])
+                assert "private-token" not in str(failure.value)
+        asyncio.run(run())
+        saved = json.loads(guard.path.read_text())
+        assert len(requests) == len(saved["receipts"]) == 1
+        assert saved["receipts"][0]["network_error_class"] == expected
+        assert saved["receipts"][0]["reason"] == "network_or_read_failure"
+        assert saved["receipts"][0]["status"] == "unknown_or_unsafe"
+        assert saved["halted"] is True
+        assert saved["pending_micro_usd"] == ENVELOPE_MICRO_USD
+        assert "private-token" not in guard.path.read_text()
+        assert "private-request" not in guard.path.read_text()
+    finally:
+        guard.close()
+
+
 def test_total_increment_ceiling_checks_before_transport(tmp_path):
     requests = []
     guard, loop, judge = models(tmp_path, lambda request: requests.append(request) or httpx.Response(200, json=receipt()))