diff --git a/test/qlib/test_exceptions_log.py b/test/qlib/test_exceptions_log.py
new file mode 100644
index 00000000..bd7ff21e
--- /dev/null
+++ b/test/qlib/test_exceptions_log.py
@@ -0,0 +1,101 @@
+"""Tests for core/exception and log infrastructure."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import pytest
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+
+# =============================================================================
+# Exception hierarchy
+# =============================================================================
+
+
+class TestExceptionHierarchy:
+    def test_workflow_error_is_exception(self):
+        from rdagent.core.exception import WorkflowError
+        with pytest.raises(WorkflowError):
+            raise WorkflowError("test")
+
+    def test_format_error_is_workflow_error(self):
+        from rdagent.core.exception import FormatError, WorkflowError
+        assert issubclass(FormatError, WorkflowError)
+
+    def test_coder_error_is_workflow_error(self):
+        from rdagent.core.exception import CoderError, WorkflowError
+        assert issubclass(CoderError, WorkflowError)
+
+    def test_code_format_error_is_coder_error(self):
+        from rdagent.core.exception import CodeFormatError, CoderError
+        assert issubclass(CodeFormatError, CoderError)
+
+    def test_custom_runtime_error_is_coder_error(self):
+        from rdagent.core.exception import CustomRuntimeError, CoderError
+        assert issubclass(CustomRuntimeError, CoderError)
+
+    def test_no_output_error_is_coder_error(self):
+        from rdagent.core.exception import NoOutputError, CoderError
+        assert issubclass(NoOutputError, CoderError)
+
+    def test_runner_error_is_exception(self):
+        from rdagent.core.exception import RunnerError
+        with pytest.raises(RunnerError):
+            raise RunnerError("test")
+
+    def test_factor_empty_error_is_coder_error(self):
+        from rdagent.core.exception import FactorEmptyError, CoderError
+        assert FactorEmptyError is CoderError
+
+    def test_model_empty_error_is_coder_error(self):
+        from rdagent.core.exception import ModelEmptyError, CoderError
+        assert ModelEmptyError is CoderError
+
+    def test_llm_unavailable_error_is_runtime_error(self):
+        from rdagent.core.exception import LLMUnavailableError
+        with pytest.raises(LLMUnavailableError):
+            raise LLMUnavailableError("LLM down")
+
+    def test_code_block_parse_error(self):
+        from rdagent.core.exception import CodeBlockParseError
+        e = CodeBlockParseError("msg", "content", "python")
+        assert e.message == "msg"
+        assert e.content == "content"
+        assert e.language == "python"
+        assert isinstance(e, Exception)
+
+    def test_coder_error_caused_by_timeout_default(self):
+        from rdagent.core.exception import CoderError
+        assert CoderError.caused_by_timeout is False
+
+
+# =============================================================================
+# RDAgentLog singleton
+# =============================================================================
+
+
+class TestRDAgentLog:
+    def test_is_singleton(self):
+        from rdagent.log.logger import RDAgentLog
+        a = RDAgentLog()
+        b = RDAgentLog()
+        assert a is b
+
+    def test_has_tag_context(self):
+        from rdagent.log.logger import RDAgentLog
+        assert hasattr(RDAgentLog, "_tag_ctx")
+
+
+# =============================================================================
+# Daily log session
+# =============================================================================
+
+
+class TestDailyLog:
+    def test_session_importable(self):
+        from rdagent.log.daily_log import session
+        assert callable(session)
diff --git a/test/qlib/test_fx_config.py b/test/qlib/test_fx_config.py
new file mode 100644
index 00000000..8ecda728
--- /dev/null
+++ b/test/qlib/test_fx_config.py
@@ -0,0 +1,64 @@
+"""Tests for fx_validator config (no langchain dependency)."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import pytest
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+
+class TestFXConfig:
+    """Test config.py directly (bypasses __init__ which imports langchain)."""
+
+    def test_config_is_dict(self):
+        # Import config module directly, not via package __init__
+        import importlib.util
+        spec = importlib.util.spec_from_file_location(
+            "fx_validator_config",
+            PROJECT_ROOT / "rdagent/scenarios/qlib/fx_validator/config.py",
+        )
+        mod = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(mod)
+        assert isinstance(mod.FX_CONFIG, dict)
+
+    def test_required_keys(self):
+        import importlib.util
+        spec = importlib.util.spec_from_file_location(
+            "fx_validator_config",
+            PROJECT_ROOT / "rdagent/scenarios/qlib/fx_validator/config.py",
+        )
+        mod = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(mod)
+        cfg = mod.FX_CONFIG
+        assert "instrument" in cfg
+        assert "max_debate_rounds" in cfg
+        assert "sessions" in cfg
+        assert "spread_bps" in cfg
+
+    def test_sessions_have_four_zones(self):
+        import importlib.util
+        spec = importlib.util.spec_from_file_location(
+            "fx_validator_config",
+            PROJECT_ROOT / "rdagent/scenarios/qlib/fx_validator/config.py",
+        )
+        mod = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(mod)
+        sessions = mod.FX_CONFIG["sessions"]
+        for zone in ("asian", "london", "ny", "overlap"):
+            start, end = sessions[zone]
+            assert isinstance(start, str)
+            assert isinstance(end, str)
+
+    def test_max_debate_rounds_positive(self):
+        import importlib.util
+        spec = importlib.util.spec_from_file_location(
+            "fx_validator_config",
+            PROJECT_ROOT / "rdagent/scenarios/qlib/fx_validator/config.py",
+        )
+        mod = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(mod)
+        assert mod.FX_CONFIG["max_debate_rounds"] > 0
diff --git a/test/qlib/test_predix_full_eval.py b/test/qlib/test_predix_full_eval.py
new file mode 100644
index 00000000..b6dccaa2
--- /dev/null
+++ b/test/qlib/test_predix_full_eval.py
@@ -0,0 +1,79 @@
+"""Tests for scripts/predix_full_eval.py pure functions and dataclasses."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import pytest
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+
+class TestFactorInfo:
+    def test_construction(self):
+        from scripts.predix_full_eval import FactorInfo
+        fi = FactorInfo(
+            workspace_hash="abc123",
+            factor_name="test_factor",
+            factor_code="x=1",
+        )
+        assert fi.workspace_hash == "abc123"
+        assert fi.factor_name == "test_factor"
+        assert fi.factor_code == "x=1"
+
+
+class TestEvalResult:
+    def test_defaults(self):
+        from scripts.predix_full_eval import EvalResult
+        er = EvalResult(factor_name="f1", workspace_hash="h1")
+        assert er.status == ""
+        assert er.ic is None
+        assert er.error_message is None
+        assert er.non_null_count == 0
+
+    def test_failed_result(self):
+        from scripts.predix_full_eval import EvalResult
+        er = EvalResult(
+            factor_name="f1", workspace_hash="h1",
+            status="failed", error_message="timeout",
+        )
+        assert er.status == "failed"
+        assert er.error_message == "timeout"
+
+    def test_to_dict(self):
+        from scripts.predix_full_eval import EvalResult
+        er = EvalResult(factor_name="f1", workspace_hash="h1", status="success", ic=0.05)
+        d = er.to_dict()
+        assert d["factor_name"] == "f1"
+        assert d["ic"] == 0.05
+        assert d["status"] == "success"
+
+
+class TestExtractFactorDescription:
+    def test_docstring_extracted(self):
+        from scripts.predix_full_eval import _extract_factor_description
+        code = '"""This is a test factor.\nComputes momentum."""\nx=1'
+        desc = _extract_factor_description(code)
+        assert "test factor" in desc
+
+    def test_comment_extraction(self):
+        from scripts.predix_full_eval import _extract_factor_description
+        code = "# Momentum factor\n# Uses 20-bar window\nx=1"
+        desc = _extract_factor_description(code)
+        assert "Momentum factor" in desc
+        assert "20-bar window" in desc
+
+    def test_no_docstring_or_comments(self):
+        from scripts.predix_full_eval import _extract_factor_description
+        code = "x = 1\ny = 2\n"
+        desc = _extract_factor_description(code)
+        assert desc == "No description available"
+
+    def test_shebang_skipped(self):
+        from scripts.predix_full_eval import _extract_factor_description
+        code = "#!/usr/bin/env python\n# Real comment\nx=1"
+        desc = _extract_factor_description(code)
+        assert "Real comment" in desc
+        assert "usr/bin" not in desc
diff --git a/test/qlib/test_utils.py b/test/qlib/test_utils.py
new file mode 100644
index 00000000..69619257
--- /dev/null
+++ b/test/qlib/test_utils.py
@@ -0,0 +1,113 @@
+"""Tests for utils/agent/apply_patch, core/prompts, utils/fmt."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import pytest
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+
+# =============================================================================
+# apply_patch data structures
+# =============================================================================
+
+
+class TestApplyPatchDatastructures:
+    def test_action_type_enum(self):
+        from rdagent.utils.agent.apply_patch import ActionType
+        assert ActionType.ADD.value == "add"
+        assert ActionType.DELETE.value == "delete"
+        assert ActionType.UPDATE.value == "update"
+
+    def test_file_change_dataclass(self):
+        from rdagent.utils.agent.apply_patch import FileChange, ActionType
+        fc = FileChange(type=ActionType.UPDATE, old_content="old", new_content="new")
+        assert fc.type == ActionType.UPDATE
+        assert fc.old_content == "old"
+        assert fc.new_content == "new"
+        assert fc.move_path is None
+
+    def test_file_change_defaults(self):
+        from rdagent.utils.agent.apply_patch import FileChange, ActionType
+        fc = FileChange(type=ActionType.ADD)
+        assert fc.old_content is None
+        assert fc.new_content is None
+
+    def test_commit_defaults(self):
+        from rdagent.utils.agent.apply_patch import Commit
+        c = Commit()
+        assert c.changes == {}
+
+    def test_commit_with_changes(self):
+        from rdagent.utils.agent.apply_patch import Commit, FileChange, ActionType
+        c = Commit(changes={"test.py": FileChange(type=ActionType.UPDATE)})
+        assert "test.py" in c.changes
+
+    def test_diff_error_is_value_error(self):
+        from rdagent.utils.agent.apply_patch import DiffError
+        with pytest.raises(DiffError):
+            raise DiffError("test error")
+
+    def test_chunk_dataclass(self):
+        from rdagent.utils.agent.apply_patch import Chunk
+        c = Chunk(orig_index=5, del_lines=["a"], ins_lines=["b", "c"])
+        assert c.orig_index == 5
+        assert c.del_lines == ["a"]
+        assert c.ins_lines == ["b", "c"]
+
+    def test_patch_action_dataclass(self):
+        from rdagent.utils.agent.apply_patch import PatchAction, ActionType
+        pa = PatchAction(type=ActionType.ADD, new_file="test.py")
+        assert pa.type == ActionType.ADD
+        assert pa.new_file == "test.py"
+
+
+# =============================================================================
+# Prompts (core/prompts.py)
+# =============================================================================
+
+
+class TestPrompts:
+    def test_prompts_loads_yaml(self, tmp_path):
+        from rdagent.core.prompts import Prompts
+        yaml_file = tmp_path / "test.yaml"
+        yaml_file.write_text("key1: value1\nkey2: value2\n")
+        p = Prompts(file_path=yaml_file)
+        assert p["key1"] == "value1"
+        assert p["key2"] == "value2"
+
+    def test_prompts_raises_on_empty(self, tmp_path):
+        from rdagent.core.prompts import Prompts
+        yaml_file = tmp_path / "empty.yaml"
+        yaml_file.write_text("")
+        with pytest.raises(ValueError, match="Failed to load"):
+            Prompts(file_path=yaml_file)
+
+    def test_prompts_is_dict_subclass(self, tmp_path):
+        from rdagent.core.prompts import Prompts
+        yaml_file = tmp_path / "test.yaml"
+        yaml_file.write_text("k: v\n")
+        p = Prompts(file_path=yaml_file)
+        assert isinstance(p, dict)
+        assert len(p) == 1
+
+
+# =============================================================================
+# SingletonBaseClass (core/utils.py)
+# =============================================================================
+
+
+class TestSingletonBaseClass:
+    def test_singleton_returns_same_instance(self):
+        from rdagent.core.utils import SingletonBaseClass
+
+        class MySingleton(SingletonBaseClass):
+            pass
+
+        a = MySingleton()
+        b = MySingleton()
+        assert a is b