diff --git a/AGENTS.md b/AGENTS.md
index 84dbadfa4..b42f1e50a 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -146,7 +146,8 @@ Run `make help` for the full list.
 ```bash
 # Backend (see backend/AGENTS.md for the full set)
 cd backend && make dev        # Gateway API with reload (port 8001)
-cd backend && make test       # Backend test suite
+cd backend && make test       # Default backend suite; excludes live and blocking-I/O tests
+cd backend && make test-blocking-io  # Strict blocking-I/O suite
 cd backend && make lint       # ruff check
 cd backend && make format     # ruff format
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index acb2a417e..04a36792a 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -335,10 +335,13 @@ before review.
 ## Testing
 
 ```bash
-# Backend tests (offline by default; excludes live external-API tests)
+# Default backend tests (excludes live and blocking-I/O tests)
 cd backend
 make test
 
+# Strict blocking-I/O tests
+make test-blocking-io
+
 # Live DeerFlowClient integration tests (explicit opt-in)
 # Requires a valid root config.yaml and API credentials.
 make test-live
diff --git a/README.md b/README.md
index 01ceac3cc..45df84a8c 100644
--- a/README.md
+++ b/README.md
@@ -1508,12 +1508,12 @@ immediately after starting any deployment that is not loopback-only.
 
 We welcome contributions! Please see [CONTRIBUTING.md](CONTRIBUTING.md) for development setup, workflow, and guidelines.
 
-Backend `make test` is offline by default and excludes live external-API
-coverage. Maintainers can explicitly run the real `DeerFlowClient` integration
-suite with `cd backend && make test-live` after providing a valid root
-`config.yaml` and API credentials; this may incur API costs and create local
-sandboxes, artifacts, or files. Direct pytest runs additionally require
-`DEER_FLOW_RUN_LIVE_TESTS=1`.
+Backend `make test` excludes live external-API and blocking-I/O coverage.
+Run `cd backend && make test-blocking-io` for strict blocking-I/O checks.
+Maintainers can run the real `DeerFlowClient` suite with `cd backend && make test-live`.
+This command requires a valid root `config.yaml` and API credentials.
+It can incur API costs and create local sandboxes, artifacts, or files.
+Direct pytest runs additionally require `DEER_FLOW_RUN_LIVE_TESTS=1`.
 
 Regression coverage includes Docker sandbox mode detection and provisioner kubeconfig-path handling tests in `backend/tests/`.
 Backend blocking-IO diagnostics are available from the repository root with
diff --git a/backend/AGENTS.md b/backend/AGENTS.md
index 4f650c3c6..69724fc99 100644
--- a/backend/AGENTS.md
+++ b/backend/AGENTS.md
@@ -151,7 +151,7 @@ make stop       # Stop all services
 make install            # Install backend dependencies
 make dev                # Run Gateway API with runtime-safe reload (port 8001)
 make gateway            # Run Gateway API only (port 8001)
-make test               # Run offline backend tests (excludes live external-API tests)
+make test               # Run offline backend tests (excludes live and blocking-I/O tests)
 make test-live          # Explicitly run live DeerFlowClient tests with real APIs
 make test-blocking-io   # Run strict Blockbuster runtime gate on tests/blocking_io/
 make lint               # Lint with ruff
@@ -216,15 +216,18 @@ float filters accept integer or real JSON numbers through `json_value_matches`.
 **Every new feature or bug fix MUST be accompanied by unit tests. No exceptions.**
 
 - Write tests in `backend/tests/` following the existing naming convention `test_<feature>.py`
-- Run the full offline suite before and after your change: `make test`
+- Run both offline targets before and after your change: `make test` and `make test-blocking-io`
 - Tests must pass before a feature is considered complete
 - For lightweight config/utility modules, prefer pure unit tests with no external dependencies
 - If a module causes circular import issues in tests, add a `sys.modules` mock in `tests/conftest.py` (see existing example for `deerflow.subagents.executor`)
 
 ```bash
-# Run all offline tests
+# Run default offline tests
 make test
 
+# Run strict blocking-I/O tests
+make test-blocking-io
+
 # Explicit live integration tests (requires config.yaml and credentials;
 # calls real APIs and may create local side effects)
 make test-live
diff --git a/backend/Makefile b/backend/Makefile
index 19aa66d00..4260d6d63 100644
--- a/backend/Makefile
+++ b/backend/Makefile
@@ -20,7 +20,7 @@ gateway:
 	PYTHONPATH=. PYTHONIOENCODING=utf-8 PYTHONUTF8=1 uv run --locked uvicorn app.gateway.app:app --host 0.0.0.0 --port 8001
 
 test:
-	PYTHONPATH=. PYTHONIOENCODING=utf-8 PYTHONUTF8=1 uv run pytest -m "not live" tests/ -v
+	PYTHONPATH=. PYTHONIOENCODING=utf-8 PYTHONUTF8=1 uv run pytest -m "not live" --ignore=tests/blocking_io tests/ -v
 
 test-live:
 	DEER_FLOW_RUN_LIVE_TESTS=1 PYTHONPATH=. PYTHONIOENCODING=utf-8 PYTHONUTF8=1 uv run pytest -m live tests/ -v -s
diff --git a/backend/README.md b/backend/README.md
index 07c260c1d..4b8999877 100644
--- a/backend/README.md
+++ b/backend/README.md
@@ -490,9 +490,12 @@ the only execution path, which keeps operational mistakes off the table. See
 ### Testing
 
 ```bash
-# Offline backend suite (live external-API tests are excluded)
+# Default offline backend suite (live external-API and blocking-I/O tests are excluded)
 make test
 
+# Strict blocking-I/O suite
+make test-blocking-io
+
 # Explicit real-API DeerFlowClient integration suite
 make test-live
 ```
diff --git a/backend/README_zh.md b/backend/README_zh.md
index 14dfa781a..26bcb3791 100644
--- a/backend/README_zh.md
+++ b/backend/README_zh.md
@@ -441,9 +441,12 @@ make migrate-rev MSG="add foo column to runs"
 ### 测试
 
 ```bash
-# 离线后端测试套件（排除调用外部真实 API 的测试）
+# 默认离线后端测试套件（排除调用外部真实 API 和阻塞式 I/O 的测试）
 make test
 
+# 严格的阻塞式 I/O 测试套件
+make test-blocking-io
+
 # 显式运行使用真实 API 的 DeerFlowClient 集成测试套件
 make test-live
 ```
diff --git a/backend/tests/test_client_live_policy.py b/backend/tests/test_client_live_policy.py
index a63db634f..95bc858fb 100644
--- a/backend/tests/test_client_live_policy.py
+++ b/backend/tests/test_client_live_policy.py
@@ -129,6 +129,7 @@ def test_make_targets_keep_default_tests_offline_and_support_live_opt_in() -> No
     live_command = _dry_run_make_target("test-live")
 
     assert 'pytest -m "not live"' in default_command
+    assert "--ignore=tests/blocking_io" in default_command
     assert "tests/" in default_command
     assert LIVE_OPT_IN not in default_command
 
@@ -159,3 +160,11 @@ def test_default_ci_workflow_does_not_opt_in_to_live_tests() -> None:
 
     assert "make test" in workflow
     assert LIVE_OPT_IN not in workflow
+
+
+def test_blocking_io_ci_workflow_owns_dedicated_suite() -> None:
+    command = _dry_run_make_target("test-blocking-io")
+    workflow = (REPO_ROOT / ".github" / "workflows" / "backend-blocking-io-tests.yml").read_text(encoding="utf-8")
+
+    assert "pytest tests/blocking_io" in command
+    assert "make test-blocking-io" in workflow