diff --git a/haiku_rag_slim/haiku/rag/agents/rlm/runner.py b/haiku_rag_slim/haiku/rag/agents/rlm/runner.py
index 97e0047a..fe7be056 100644
--- a/haiku_rag_slim/haiku/rag/agents/rlm/runner.py
+++ b/haiku_rag_slim/haiku/rag/agents/rlm/runner.py
@@ -8,7 +8,7 @@ from io import StringIO
 from typing import Any
 
 
-def build_namespace(
+def build_namespace(  # pragma: no cover
     client: Any, config: Any, context: Any, loop: asyncio.AbstractEventLoop
 ) -> dict[str, Any]:
     """Build execution namespace with haiku.rag functions injected."""
@@ -134,7 +134,7 @@ def send_response(result: dict[str, Any]) -> None:
     sys.stdout.flush()
 
 
-async def main() -> None:
+async def main() -> None:  # pragma: no cover
     """Main entry point for container execution.
 
     Runs a loop reading length-prefixed JSON messages and executing code.
diff --git a/haiku_rag_slim/haiku/rag/chat/app.py b/haiku_rag_slim/haiku/rag/chat/app.py
index 7fcef2ec..8a84e05e 100644
--- a/haiku_rag_slim/haiku/rag/chat/app.py
+++ b/haiku_rag_slim/haiku/rag/chat/app.py
@@ -34,7 +34,7 @@ try:
 
     logfire.configure(send_to_logfire="if-token-present", console=False)
     logfire.instrument_pydantic_ai()
-except ImportError:
+except ImportError:  # pragma: no cover
     pass
 
 try:
@@ -47,7 +47,7 @@ try:
     from haiku.rag.chat.widgets.chat_history import ChatHistory, CitationWidget
 
     TEXTUAL_AVAILABLE = True
-except ImportError:
+except ImportError:  # pragma: no cover
     TEXTUAL_AVAILABLE = False
     App = object  # type: ignore
     SystemCommand = object  # type: ignore
diff --git a/haiku_rag_slim/haiku/rag/inspector/app.py b/haiku_rag_slim/haiku/rag/inspector/app.py
index 67c45dda..6fc8d774 100644
--- a/haiku_rag_slim/haiku/rag/inspector/app.py
+++ b/haiku_rag_slim/haiku/rag/inspector/app.py
@@ -21,7 +21,7 @@ try:
     from haiku.rag.inspector.widgets.search_modal import SearchModal
 
     TEXTUAL_AVAILABLE = True
-except ImportError:
+except ImportError:  # pragma: no cover
     TEXTUAL_AVAILABLE = False
     App = object  # type: ignore
 
diff --git a/haiku_rag_slim/haiku/rag/utils.py b/haiku_rag_slim/haiku/rag/utils.py
index b038dde0..79e4f9c6 100644
--- a/haiku_rag_slim/haiku/rag/utils.py
+++ b/haiku_rag_slim/haiku/rag/utils.py
@@ -468,7 +468,7 @@ async def is_up_to_date() -> tuple[bool, Version, Version]:
             response = await client.get("https://pypi.org/pypi/haiku.rag/json")
             data = response.json()
             pypi_version = parse(data["info"]["version"])
-        except Exception:
+        except Exception:  # pragma: no cover
             # If no network connection, do not raise alarms.
             pypi_version = running_version
     return running_version >= pypi_version, running_version, pypi_version
diff --git a/pyproject.toml b/pyproject.toml
index 218ca63f..e2f72850 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -128,3 +128,14 @@ markers = [
 
 # pyproject.toml
 filterwarnings = ["error", "ignore::UserWarning", "ignore::DeprecationWarning"]
+
+[tool.coverage.run]
+source = ["haiku_rag_slim"]
+
+[tool.coverage.report]
+show_missing = true
+exclude_also = [
+    "if TYPE_CHECKING:",
+    "@abstractmethod",
+    "raise NotImplementedError",
+]
diff --git a/tests/agents/rlm/test_runner.py b/tests/agents/rlm/test_runner.py
new file mode 100644
index 00000000..18104917
--- /dev/null
+++ b/tests/agents/rlm/test_runner.py
@@ -0,0 +1,50 @@
+import json
+from io import StringIO
+
+from haiku.rag.agents.rlm.runner import execute_code, send_response
+
+
+def test_execute_code_success():
+    namespace: dict = {}
+    result = execute_code("x = 1 + 1", namespace, max_output_chars=1000)
+    assert result["success"] is True
+    assert result["stderr"] == ""
+
+
+def test_execute_code_stdout_capture():
+    namespace: dict = {}
+    result = execute_code("print('hello')", namespace, max_output_chars=1000)
+    assert result["success"] is True
+    assert "hello" in result["stdout"]
+
+
+def test_execute_code_exception():
+    namespace: dict = {}
+    result = execute_code("raise ValueError('boom')", namespace, max_output_chars=1000)
+    assert result["success"] is False
+    assert "ValueError" in result["stderr"]
+    assert "boom" in result["stderr"]
+
+
+def test_execute_code_output_truncation():
+    namespace: dict = {}
+    code = "print('x' * 100)"
+    result = execute_code(code, namespace, max_output_chars=10)
+    assert result["success"] is True
+    assert "truncated" in result["stdout"]
+    assert len(result["stdout"]) < 100
+
+
+def test_send_response(monkeypatch):
+    buf = StringIO()
+    monkeypatch.setattr("sys.stdout", buf)
+
+    payload = {"success": True, "stdout": "hi", "stderr": ""}
+    send_response(payload)
+
+    output = buf.getvalue()
+    lines = output.split("\n", 1)
+    length = int(lines[0])
+    body = lines[1]
+    assert json.loads(body) == payload
+    assert length == len(json.dumps(payload))
diff --git a/tests/test_logging.py b/tests/test_logging.py
new file mode 100644
index 00000000..325a3ce5
--- /dev/null
+++ b/tests/test_logging.py
@@ -0,0 +1,38 @@
+import logging
+
+from haiku.rag.logging import configure_cli_logging, get_logger
+
+
+def test_get_logger():
+    logger = get_logger()
+    assert logger.name == "haiku.rag"
+    assert logger.level == logging.INFO
+    assert len(logger.handlers) == 1
+    assert logger.propagate is False
+
+
+def test_get_logger_idempotent():
+    logger1 = get_logger()
+    logger2 = get_logger()
+    assert logger1 is logger2
+    assert len(logger2.handlers) == 1
+
+
+def test_configure_cli_logging():
+    logger = configure_cli_logging()
+    assert logger.name == "haiku.rag"
+    assert logger.propagate is False
+
+    root = logging.getLogger()
+    assert root.level == logging.ERROR
+    assert len(root.handlers) == 0
+
+    for name in ("httpx", "httpcore", "docling", "urllib3", "asyncio"):
+        noisy = logging.getLogger(name)
+        assert noisy.level == logging.ERROR
+        assert noisy.propagate is False
+
+
+def test_configure_cli_logging_custom_level():
+    logger = configure_cli_logging(level=logging.DEBUG)
+    assert logger.level == logging.DEBUG
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 8256cf3f..f486d120 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -318,3 +318,285 @@ def test_get_package_versions():
     for key, value in versions.items():
         assert isinstance(value, str)
         assert len(value) > 0
+
+
+# --- parse_datetime tests ---
+
+
+def test_parse_datetime_iso8601():
+    from haiku.rag.utils import parse_datetime
+
+    dt = parse_datetime("2025-01-15T14:30:00")
+    assert dt.year == 2025
+    assert dt.month == 1
+    assert dt.day == 15
+    assert dt.hour == 14
+    assert dt.minute == 30
+
+
+def test_parse_datetime_date_only():
+    from haiku.rag.utils import parse_datetime
+
+    dt = parse_datetime("2025-01-15")
+    assert dt.year == 2025
+    assert dt.month == 1
+    assert dt.day == 15
+
+
+def test_parse_datetime_with_timezone():
+    from haiku.rag.utils import parse_datetime
+
+    dt = parse_datetime("2025-01-15T14:30:00+00:00")
+    assert dt.year == 2025
+    assert dt.tzinfo is not None
+
+
+def test_parse_datetime_invalid():
+    from haiku.rag.utils import parse_datetime
+
+    with pytest.raises(ValueError, match="Could not parse datetime"):
+        parse_datetime("not-a-date")
+
+
+# --- to_utc tests ---
+
+
+def test_to_utc_naive_datetime():
+    from datetime import datetime
+
+    from haiku.rag.utils import to_utc
+
+    naive = datetime(2025, 6, 15, 12, 0, 0)
+    result = to_utc(naive)
+    assert result.tzinfo is not None
+
+
+def test_to_utc_utc_datetime():
+    from datetime import UTC, datetime
+
+    from haiku.rag.utils import to_utc
+
+    utc_dt = datetime(2025, 6, 15, 12, 0, 0, tzinfo=UTC)
+    result = to_utc(utc_dt)
+    assert result is utc_dt
+
+
+def test_to_utc_aware_non_utc():
+    from datetime import UTC, datetime, timedelta, timezone
+
+    from haiku.rag.utils import to_utc
+
+    eastern = timezone(timedelta(hours=-5))
+    aware = datetime(2025, 6, 15, 12, 0, 0, tzinfo=eastern)
+    result = to_utc(aware)
+    assert result.tzinfo == UTC
+    assert result.hour == 17
+
+
+# --- apply_common_settings tests ---
+
+
+def test_apply_common_settings_no_settings():
+    from haiku.rag.config.models import ModelConfig
+    from haiku.rag.utils import apply_common_settings
+
+    mc = ModelConfig(provider="openai", name="gpt-4o")
+    result = apply_common_settings(None, dict, mc)
+    assert result is None
+
+
+def test_apply_common_settings_temperature():
+    from haiku.rag.config.models import ModelConfig
+    from haiku.rag.utils import apply_common_settings
+
+    mc = ModelConfig(provider="openai", name="gpt-4o", temperature=0.7)
+    result = apply_common_settings(None, dict, mc)
+    assert result is not None
+    assert result["temperature"] == 0.7
+
+
+def test_apply_common_settings_max_tokens():
+    from haiku.rag.config.models import ModelConfig
+    from haiku.rag.utils import apply_common_settings
+
+    mc = ModelConfig(provider="openai", name="gpt-4o", max_tokens=500)
+    result = apply_common_settings(None, dict, mc)
+    assert result is not None
+    assert result["max_tokens"] == 500
+
+
+def test_apply_common_settings_existing():
+    from haiku.rag.config.models import ModelConfig
+    from haiku.rag.utils import apply_common_settings
+
+    mc = ModelConfig(provider="openai", name="gpt-4o", temperature=0.5)
+    existing = {"some_key": "value"}
+    result = apply_common_settings(existing, dict, mc)
+    assert result is not None
+    assert result["temperature"] == 0.5
+    assert result["some_key"] == "value"
+
+
+# --- format_bytes tests ---
+
+
+def test_format_bytes():
+    from haiku.rag.utils import format_bytes
+
+    assert format_bytes(0) == "0.0 B"
+    assert format_bytes(512) == "512.0 B"
+    assert format_bytes(1024) == "1.0 KB"
+    assert format_bytes(1048576) == "1.0 MB"
+    assert format_bytes(1073741824) == "1.0 GB"
+    assert format_bytes(1099511627776) == "1.0 TB"
+    assert format_bytes(1125899906842624) == "1.0 PB"
+
+
+# --- format_citations tests ---
+
+
+def test_format_citations_empty():
+    from haiku.rag.utils import format_citations
+
+    assert format_citations([]) == ""
+
+
+def test_format_citations_with_citation():
+    from haiku.rag.agents.research.models import Citation
+    from haiku.rag.utils import format_citations
+
+    citation = Citation(
+        document_id="doc1",
+        chunk_id="chunk1",
+        document_uri="test://doc",
+        document_title="Test Doc",
+        content="Some content",
+        page_numbers=[1],
+        headings=["Intro"],
+    )
+    result = format_citations([citation])
+    assert "[doc1:chunk1]" in result
+    assert "Test Doc" in result
+    assert "p. 1" in result
+    assert "Section: Intro" in result
+    assert "Some content" in result
+
+
+def test_format_citations_multiple_pages():
+    from haiku.rag.agents.research.models import Citation
+    from haiku.rag.utils import format_citations
+
+    citation = Citation(
+        document_id="doc1",
+        chunk_id="chunk1",
+        document_uri="test://doc",
+        content="Content",
+        page_numbers=[1, 2, 3],
+    )
+    result = format_citations([citation])
+    assert "pp. 1-3" in result
+
+
+def test_format_citations_no_title():
+    from haiku.rag.agents.research.models import Citation
+    from haiku.rag.utils import format_citations
+
+    citation = Citation(
+        document_id="doc1",
+        chunk_id="chunk1",
+        document_uri="test://doc",
+        content="Content",
+    )
+    result = format_citations([citation])
+    assert "test://doc" in result
+
+
+# --- format_citations_rich tests ---
+
+
+def test_format_citations_rich_empty():
+    from haiku.rag.utils import format_citations_rich
+
+    assert format_citations_rich([]) == []
+
+
+def test_format_citations_rich_with_citation():
+    from rich.panel import Panel
+    from rich.text import Text
+
+    from haiku.rag.agents.research.models import Citation
+    from haiku.rag.utils import format_citations_rich
+
+    citation = Citation(
+        document_id="doc1",
+        chunk_id="chunk1",
+        document_uri="test://doc",
+        document_title="Test Doc",
+        content="Some content",
+        page_numbers=[1, 2],
+        headings=["Intro"],
+    )
+    result = format_citations_rich([citation])
+    assert len(result) == 2
+    assert isinstance(result[0], Text)
+    assert isinstance(result[1], Panel)
+
+
+# --- get_default_data_dir tests ---
+
+
+def test_get_default_data_dir():
+    from pathlib import Path
+
+    from haiku.rag.utils import get_default_data_dir
+
+    result = get_default_data_dir()
+    assert isinstance(result, Path)
+    assert "haiku.rag" in str(result)
+
+
+# --- build_prompt tests ---
+
+
+def test_build_prompt_without_preamble():
+    from haiku.rag.config.models import AppConfig
+    from haiku.rag.utils import build_prompt
+
+    config = AppConfig()
+    result = build_prompt("Base prompt", config)
+    assert result == "Base prompt"
+
+
+def test_build_prompt_with_preamble():
+    from haiku.rag.config.models import AppConfig, PromptsConfig
+    from haiku.rag.utils import build_prompt
+
+    config = AppConfig(prompts=PromptsConfig(domain_preamble="You are a legal expert."))
+    result = build_prompt("Base prompt", config)
+    assert result == "You are a legal expert.\n\nBase prompt"
+
+
+# --- is_up_to_date tests ---
+
+
+@pytest.mark.asyncio
+async def test_is_up_to_date(monkeypatch):
+    from unittest.mock import AsyncMock, MagicMock
+
+    import httpx
+
+    from haiku.rag.utils import is_up_to_date
+
+    mock_response = MagicMock()
+    mock_response.json.return_value = {"info": {"version": "0.0.1"}}
+
+    mock_client = AsyncMock()
+    mock_client.get = AsyncMock(return_value=mock_response)
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    monkeypatch.setattr(httpx, "AsyncClient", lambda: mock_client)
+
+    is_current, running, latest = await is_up_to_date()
+    assert is_current is True
+    assert running >= latest
diff --git a/tests/tools/test_prompts.py b/tests/tools/test_prompts.py
new file mode 100644
index 00000000..ac82c28d
--- /dev/null
+++ b/tests/tools/test_prompts.py
@@ -0,0 +1,53 @@
+from haiku.rag.tools.prompts import build_tools_prompt
+
+
+def test_empty_features():
+    result = build_tools_prompt([])
+    assert result == ""
+
+
+def test_single_feature_search():
+    result = build_tools_prompt(["search"])
+    assert "search" in result
+    assert "document_name" in result.lower()
+
+
+def test_single_feature_documents():
+    result = build_tools_prompt(["documents"])
+    assert "list_documents" in result
+    assert "summarize_document" in result
+    assert "get_document" in result
+
+
+def test_single_feature_qa():
+    result = build_tools_prompt(["qa"])
+    assert "ask" in result
+    assert "document_name" in result.lower()
+
+
+def test_single_feature_analysis():
+    result = build_tools_prompt(["analysis"])
+    assert "analyze" in result
+
+
+def test_multiple_features():
+    result = build_tools_prompt(["search", "qa", "documents"])
+    assert "search" in result
+    assert "ask" in result
+    assert "list_documents" in result
+
+
+def test_search_and_qa_both_add_document_name_examples():
+    result = build_tools_prompt(["search", "qa"])
+    assert "search for embeddings" in result.lower() or "embeddings" in result
+    assert "what does the ML paper say" in result or "ML paper" in result
+
+
+def test_unknown_features_ignored():
+    result = build_tools_prompt(["nonexistent", "also_fake"])
+    assert result == ""
+
+
+def test_unknown_mixed_with_known():
+    result = build_tools_prompt(["nonexistent", "search"])
+    assert "search" in result