diff --git a/tests/instruments/test_cors_instrument.py b/tests/instruments/test_cors_instrument.py
new file mode 100644
index 0000000..7ea6e98
--- /dev/null
+++ b/tests/instruments/test_cors_instrument.py
@@ -0,0 +1,43 @@
+from lite_bootstrap.instruments.cors_instrument import CorsConfig, CorsInstrument
+
+
+def test_cors_instrument_not_ready_without_origins_or_regex() -> None:
+    instrument = CorsInstrument(bootstrap_config=CorsConfig())
+    assert not instrument.is_ready()
+    assert instrument.not_ready_message == "cors_allowed_origins or cors_allowed_origin_regex must be provided"
+
+
+def test_cors_instrument_ready_with_origins() -> None:
+    instrument = CorsInstrument(bootstrap_config=CorsConfig(cors_allowed_origins=["http://test"]))
+    assert instrument.is_ready()
+
+
+def test_cors_instrument_ready_with_regex() -> None:
+    instrument = CorsInstrument(bootstrap_config=CorsConfig(cors_allowed_origin_regex=r"https?://.*"))
+    assert instrument.is_ready()
+
+
+def test_cors_instrument_ready_with_both() -> None:
+    instrument = CorsInstrument(
+        bootstrap_config=CorsConfig(
+            cors_allowed_origins=["http://test"],
+            cors_allowed_origin_regex=r"https?://.*",
+        ),
+    )
+    assert instrument.is_ready()
+
+
+def test_cors_instrument_config_defaults() -> None:
+    config = CorsConfig()
+    assert config.cors_allowed_origins == []
+    assert config.cors_allowed_methods == []
+    assert config.cors_allowed_headers == []
+    assert config.cors_exposed_headers == []
+    assert config.cors_allowed_credentials is False
+    assert config.cors_allowed_origin_regex is None
+    expected_max_age = 600
+    assert config.cors_max_age == expected_max_age
+
+
+def test_cors_check_dependencies() -> None:
+    assert CorsInstrument.check_dependencies() is True
diff --git a/tests/instruments/test_healthchecks_instrument.py b/tests/instruments/test_healthchecks_instrument.py
new file mode 100644
index 0000000..16e07a8
--- /dev/null
+++ b/tests/instruments/test_healthchecks_instrument.py
@@ -0,0 +1,45 @@
+from lite_bootstrap.instruments.healthchecks_instrument import HealthChecksConfig, HealthChecksInstrument
+
+
+def test_healthchecks_instrument_ready_by_default() -> None:
+    instrument = HealthChecksInstrument(bootstrap_config=HealthChecksConfig())
+    assert instrument.is_ready()
+
+
+def test_healthchecks_instrument_not_ready_when_disabled() -> None:
+    instrument = HealthChecksInstrument(bootstrap_config=HealthChecksConfig(health_checks_enabled=False))
+    assert not instrument.is_ready()
+    assert instrument.not_ready_message == "health_checks_enabled is False"
+
+
+def test_healthchecks_render_data_default() -> None:
+    instrument = HealthChecksInstrument(bootstrap_config=HealthChecksConfig())
+    data = instrument.render_health_check_data()
+    assert data == {
+        "service_version": "1.0.0",
+        "service_name": "micro-service",
+        "health_status": True,
+    }
+
+
+def test_healthchecks_render_data_custom() -> None:
+    instrument = HealthChecksInstrument(
+        bootstrap_config=HealthChecksConfig(service_name="my-svc", service_version="2.0.0"),
+    )
+    data = instrument.render_health_check_data()
+    assert data == {
+        "service_version": "2.0.0",
+        "service_name": "my-svc",
+        "health_status": True,
+    }
+
+
+def test_healthchecks_config_defaults() -> None:
+    config = HealthChecksConfig()
+    assert config.health_checks_enabled is True
+    assert config.health_checks_path == "/health/"
+    assert config.health_checks_include_in_schema is False
+
+
+def test_healthchecks_check_dependencies() -> None:
+    assert HealthChecksInstrument.check_dependencies() is True
diff --git a/tests/instruments/test_prometheus_instrument.py b/tests/instruments/test_prometheus_instrument.py
new file mode 100644
index 0000000..a802d3a
--- /dev/null
+++ b/tests/instruments/test_prometheus_instrument.py
@@ -0,0 +1,35 @@
+from lite_bootstrap.instruments.prometheus_instrument import PrometheusConfig, PrometheusInstrument
+
+
+def test_prometheus_instrument_ready_with_default_path() -> None:
+    instrument = PrometheusInstrument(bootstrap_config=PrometheusConfig())
+    assert instrument.is_ready()
+
+
+def test_prometheus_instrument_not_ready_with_empty_path() -> None:
+    instrument = PrometheusInstrument(bootstrap_config=PrometheusConfig(prometheus_metrics_path=""))
+    assert not instrument.is_ready()
+    assert instrument.not_ready_message == "prometheus_metrics_path is empty or not valid"
+
+
+def test_prometheus_instrument_not_ready_with_invalid_path() -> None:
+    # No leading slash → invalid per is_valid_path regex.
+    instrument = PrometheusInstrument(bootstrap_config=PrometheusConfig(prometheus_metrics_path="metrics"))
+    assert not instrument.is_ready()
+
+
+def test_prometheus_instrument_ready_with_custom_valid_path() -> None:
+    instrument = PrometheusInstrument(
+        bootstrap_config=PrometheusConfig(prometheus_metrics_path="/custom-metrics/"),
+    )
+    assert instrument.is_ready()
+
+
+def test_prometheus_config_defaults() -> None:
+    config = PrometheusConfig()
+    assert config.prometheus_metrics_path == "/metrics"
+    assert config.prometheus_metrics_include_in_schema is False
+
+
+def test_prometheus_check_dependencies() -> None:
+    assert PrometheusInstrument.check_dependencies() is True
diff --git a/tests/instruments/test_swagger_instrument.py b/tests/instruments/test_swagger_instrument.py
new file mode 100644
index 0000000..10fee98
--- /dev/null
+++ b/tests/instruments/test_swagger_instrument.py
@@ -0,0 +1,17 @@
+from lite_bootstrap.instruments.swagger_instrument import SwaggerConfig, SwaggerInstrument
+
+
+def test_swagger_instrument_ready_by_default() -> None:
+    instrument = SwaggerInstrument(bootstrap_config=SwaggerConfig())
+    assert instrument.is_ready()
+
+
+def test_swagger_config_defaults() -> None:
+    config = SwaggerConfig()
+    assert config.swagger_static_path == "/static"
+    assert config.swagger_path == "/docs"
+    assert config.swagger_offline_docs is False
+
+
+def test_swagger_check_dependencies() -> None:
+    assert SwaggerInstrument.check_dependencies() is True
diff --git a/tests/test_path.py b/tests/test_path.py
new file mode 100644
index 0000000..8480cfb
--- /dev/null
+++ b/tests/test_path.py
@@ -0,0 +1,38 @@
+import pytest
+
+from lite_bootstrap.helpers.path import is_valid_path
+
+
+@pytest.mark.parametrize(
+    "path",
+    [
+        "/metrics",
+        "/health/",
+        "/api/v1/users",
+        "/foo.bar",
+        "/foo_bar",
+        "/foo-bar",
+        "/a",
+        "/a/",
+    ],
+)
+def test_is_valid_path_accepts_valid(path: str) -> None:
+    assert is_valid_path(path) is True
+
+
+@pytest.mark.parametrize(
+    "path",
+    [
+        "",
+        "foo",
+        "foo/",
+        "/foo bar",
+        "/foo?bar",
+        "/foo#bar",
+        "/",
+        "//foo",
+        "/foo//bar",
+    ],
+)
+def test_is_valid_path_rejects_invalid(path: str) -> None:
+    assert is_valid_path(path) is False