diff --git a/pyproject.toml b/pyproject.toml
index b3e39cc..880ded3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -43,6 +43,10 @@ decnet = "decnet.cli:app"
 
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
+addopts = "-m 'not fuzz' -v -q -x -n logical"
+markers = [
+    "fuzz: hypothesis-based fuzz tests (slow, run with -m fuzz or -m '' for all)",
+]
 filterwarnings = [
     "ignore::pytest.PytestUnhandledThreadExceptionWarning",
     "ignore::DeprecationWarning",
diff --git a/tests/api/auth/test_change_pass.py b/tests/api/auth/test_change_pass.py
index 0940410..efda0f4 100644
--- a/tests/api/auth/test_change_pass.py
+++ b/tests/api/auth/test_change_pass.py
@@ -36,6 +36,7 @@ async def test_change_password(client: httpx.AsyncClient) -> None:
     assert resp4.status_code == 200
     assert resp4.json()["must_change_password"] is False
 
+@pytest.mark.fuzz
 @pytest.mark.anyio
 @settings(**_FUZZ_SETTINGS)
 @given(
diff --git a/tests/api/auth/test_login.py b/tests/api/auth/test_login.py
index a5a512c..1e04b78 100644
--- a/tests/api/auth/test_login.py
+++ b/tests/api/auth/test_login.py
@@ -34,14 +34,14 @@ async def test_login_failure(client: httpx.AsyncClient) -> None:
     )
     assert response.status_code == 401
 
+@pytest.mark.anyio
+@pytest.mark.fuzz
 @pytest.mark.anyio
 @settings(**_FUZZ_SETTINGS)
 @given(
     username=st.text(min_size=0, max_size=2048),
     password=st.text(min_size=0, max_size=2048)
 )
-
-@pytest.mark.anyio
 async def test_fuzz_login(client: httpx.AsyncClient, username: str, password: str) -> None:
     """Fuzz the login endpoint with random strings (including non-ASCII)."""
     _payload: dict[str, str] = {"username": username, "password": password}
diff --git a/tests/api/bounty/test_get_bounties.py b/tests/api/bounty/test_get_bounties.py
index 0c21c4a..92196dd 100644
--- a/tests/api/bounty/test_get_bounties.py
+++ b/tests/api/bounty/test_get_bounties.py
@@ -1,5 +1,7 @@
 import pytest
 import httpx
+from hypothesis import given, settings, strategies as st
+from ..conftest import _FUZZ_SETTINGS
 
 @pytest.mark.anyio
 async def test_add_and_get_bounty(client: httpx.AsyncClient, auth_token: str):
@@ -17,3 +19,24 @@ async def test_bounty_pagination(client: httpx.AsyncClient, auth_token: str):
     resp = await client.get("/api/v1/bounty?limit=1&offset=0", headers={"Authorization": f"Bearer {auth_token}"})
     assert resp.status_code == 200
     assert resp.json()["limit"] == 1
+
+@pytest.mark.fuzz
+@pytest.mark.anyio
+@settings(**_FUZZ_SETTINGS)
+@given(
+    limit=st.integers(min_value=-2000, max_value=5000),
+    offset=st.integers(min_value=-2000, max_value=5000),
+    bounty_type=st.one_of(st.none(), st.text(max_size=256)),
+    search=st.one_of(st.none(), st.text(max_size=2048)),
+)
+async def test_fuzz_bounty_query(client: httpx.AsyncClient, auth_token: str, limit: int, offset: int, bounty_type, search) -> None:
+    params = {"limit": limit, "offset": offset}
+    if bounty_type is not None:
+        params["bounty_type"] = bounty_type
+    if search is not None:
+        params["search"] = search
+    try:
+        resp = await client.get("/api/v1/bounty", params=params, headers={"Authorization": f"Bearer {auth_token}"})
+        assert resp.status_code in (200, 422)
+    except (UnicodeEncodeError,):
+        pass
diff --git a/tests/api/conftest.py b/tests/api/conftest.py
index 38ee02c..51b716e 100644
--- a/tests/api/conftest.py
+++ b/tests/api/conftest.py
@@ -1,47 +1,57 @@
 import os
 import json
+import uuid as _uuid
 import pytest
-from typing import Generator, Any, AsyncGenerator
+from typing import Any, AsyncGenerator
 from pathlib import Path
+from sqlmodel import SQLModel
 import httpx
 from hypothesis import HealthCheck
-from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+from sqlalchemy.pool import StaticPool
 
-# Ensure required env vars are set to non-bad values for tests before anything imports decnet.env
+# Must be set before any decnet import touches decnet.env
 os.environ["DECNET_JWT_SECRET"] = "test-secret-key-at-least-32-chars-long!!"
 os.environ["DECNET_ADMIN_PASSWORD"] = "test-password-123"
 
 from decnet.web.api import app
 from decnet.web.dependencies import repo
-from decnet.web.db.sqlite.database import get_async_engine
+from decnet.web.db.models import User
+from decnet.web.auth import get_password_hash
 from decnet.env import DECNET_ADMIN_USER, DECNET_ADMIN_PASSWORD
 import decnet.config
 
-TEST_STATE_FILE = Path("test-decnet-state.json")
 
 @pytest.fixture(scope="function", autouse=True)
-async def setup_db(worker_id, monkeypatch) -> AsyncGenerator[None, None]:
-    import uuid
-    # Use worker-specific in-memory DB with shared cache for maximum speed
-    unique_id = uuid.uuid4().hex
-    db_path = f"file:memdb_{worker_id}_{unique_id}?mode=memory&cache=shared"
-    
-    # Patch the global repo singleton
-    monkeypatch.setattr(repo, "db_path", db_path)
-    
-    engine = get_async_engine(db_path)
-    session_factory = async_sessionmaker(
-        engine, class_=AsyncSession, expire_on_commit=False
-    )
-    
+async def setup_db(monkeypatch) -> AsyncGenerator[None, None]:
+    # Unique in-memory DB per test — no file I/O, no WAL/SHM side-cars
+    db_url = f"sqlite+aiosqlite:///file:testdb_{_uuid.uuid4().hex}?mode=memory&cache=shared"
+    engine = create_async_engine(db_url, connect_args={"uri": True}, poolclass=StaticPool)
+    session_factory = async_sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)
+
+    # Patch BOTH — session_factory is what all queries actually use
     monkeypatch.setattr(repo, "engine", engine)
     monkeypatch.setattr(repo, "session_factory", session_factory)
-    
-    # Initialize the in-memory DB (tables + admin)
-    repo.reinitialize()
-    
+
+    # Create schema
+    async with engine.begin() as conn:
+        await conn.run_sync(SQLModel.metadata.create_all)
+
+    # Seed admin user
+    async with session_factory() as session:
+        if not (await session.execute(select(User).where(User.username == DECNET_ADMIN_USER))).scalar_one_or_none():
+            session.add(User(
+                uuid=str(_uuid.uuid4()),
+                username=DECNET_ADMIN_USER,
+                password_hash=get_password_hash(DECNET_ADMIN_PASSWORD),
+                role="admin",
+                must_change_password=True,
+            ))
+            await session.commit()
+
     yield
-    
+
     await engine.dispose()
 
 @pytest.fixture
@@ -55,11 +65,13 @@ async def auth_token(client: httpx.AsyncClient) -> str:
     return resp.json()["access_token"]
 
 @pytest.fixture(autouse=True)
-def patch_state_file(monkeypatch):
-    monkeypatch.setattr(decnet.config, "STATE_FILE", TEST_STATE_FILE)
+def patch_state_file(monkeypatch, tmp_path) -> Path:
+    state_file = tmp_path / "decnet-state.json"
+    monkeypatch.setattr(decnet.config, "STATE_FILE", state_file)
+    return state_file
 
 @pytest.fixture
-def mock_state_file():
+def mock_state_file(patch_state_file: Path):
     _test_state = {
         "config": {
             "mode": "unihost",
@@ -103,14 +115,15 @@ def mock_state_file():
         },
         "compose_path": "test-compose.yml"
     }
-    TEST_STATE_FILE.write_text(json.dumps(_test_state))
+    patch_state_file.write_text(json.dumps(_test_state))
     yield _test_state
-    if TEST_STATE_FILE.exists():
-        TEST_STATE_FILE.unlink()
 
 # Share fuzz settings across API tests
+# FUZZ_EXAMPLES: keep low for dev speed; bump via HYPOTHESIS_MAX_EXAMPLES env var in CI
+import os as _os
+_FUZZ_EXAMPLES = int(_os.environ.get("HYPOTHESIS_MAX_EXAMPLES", "10"))
 _FUZZ_SETTINGS: dict[str, Any] = {
-    "max_examples": 50,
+    "max_examples": _FUZZ_EXAMPLES,
     "deadline": None,
-    "suppress_health_check": [HealthCheck.function_scoped_fixture]
+    "suppress_health_check": [HealthCheck.function_scoped_fixture],
 }
diff --git a/tests/api/fleet/test_get_deckies.py b/tests/api/fleet/test_get_deckies.py
index 036a9fc..93cdcb4 100644
--- a/tests/api/fleet/test_get_deckies.py
+++ b/tests/api/fleet/test_get_deckies.py
@@ -1,6 +1,8 @@
 import pytest
 import httpx
+from hypothesis import given, settings, strategies as st
 from decnet.env import DECNET_ADMIN_USER, DECNET_ADMIN_PASSWORD
+from ..conftest import _FUZZ_SETTINGS
 
 @pytest.mark.anyio
 async def test_get_deckies_endpoint(mock_state_file, client: httpx.AsyncClient, auth_token: str):
@@ -10,3 +12,15 @@ async def test_get_deckies_endpoint(mock_state_file, client: httpx.AsyncClient,
     assert len(_data) == 2
     assert _data[0]["name"] == "test-decky-1"
     assert _data[0]["service_config"]["ssh"]["banner"] == "SSH-2.0-OpenSSH_8.9"
+
+@pytest.mark.fuzz
+@pytest.mark.anyio
+@settings(**_FUZZ_SETTINGS)
+@given(token=st.text(min_size=0, max_size=4096))
+async def test_fuzz_deckies_auth(client: httpx.AsyncClient, token: str) -> None:
+    """Fuzz the Authorization header on the deckies endpoint."""
+    try:
+        resp = await client.get("/api/v1/deckies", headers={"Authorization": f"Bearer {token}"})
+        assert resp.status_code in (200, 401, 422)
+    except (UnicodeEncodeError,):
+        pass
diff --git a/tests/api/logs/test_get_logs.py b/tests/api/logs/test_get_logs.py
index 4952b19..edca28c 100644
--- a/tests/api/logs/test_get_logs.py
+++ b/tests/api/logs/test_get_logs.py
@@ -22,6 +22,7 @@ async def test_get_logs_success(client: httpx.AsyncClient, auth_token: str) -> N
     assert data["total"] >= 0
     assert isinstance(data["data"], list)
 
+@pytest.mark.fuzz
 @pytest.mark.anyio
 @settings(**_FUZZ_SETTINGS)
 @given(
diff --git a/tests/api/logs/test_histogram.py b/tests/api/logs/test_histogram.py
index ae8a984..0c03b52 100644
--- a/tests/api/logs/test_histogram.py
+++ b/tests/api/logs/test_histogram.py
@@ -9,7 +9,9 @@ import json
 import pytest
 from datetime import datetime, timedelta
 from freezegun import freeze_time
+from hypothesis import given, settings, strategies as st
 from decnet.web.db.sqlite.repository import SQLiteRepository
+from ..conftest import _FUZZ_SETTINGS
 
 
 @pytest.fixture
@@ -98,3 +100,18 @@ async def test_histogram_search_filter(repo):
     result = await repo.get_log_histogram(search="service:ssh", interval_minutes=15)
     total = sum(r["count"] for r in result)
     assert total == 1
+
+
+@pytest.mark.fuzz
+@pytest.mark.anyio
+@settings(**_FUZZ_SETTINGS)
+@given(
+    search=st.one_of(st.none(), st.text(max_size=512)),
+    interval_minutes=st.integers(min_value=1, max_value=10000),
+)
+async def test_fuzz_histogram(repo, search: str | None, interval_minutes: int) -> None:
+    """Fuzz histogram params — must never raise uncaught exceptions."""
+    try:
+        await repo.get_log_histogram(search=search, interval_minutes=interval_minutes)
+    except Exception as exc:
+        pytest.fail(f"get_log_histogram raised unexpectedly: {exc}")
diff --git a/tests/api/stats/test_get_stats.py b/tests/api/stats/test_get_stats.py
index de39644..0438e5c 100644
--- a/tests/api/stats/test_get_stats.py
+++ b/tests/api/stats/test_get_stats.py
@@ -30,6 +30,7 @@ async def test_stats_includes_deployed_count(mock_state_file, client: httpx.Asyn
     assert "deployed_deckies" in _data
     assert _data["deployed_deckies"] == 2
 
+@pytest.mark.fuzz
 @pytest.mark.anyio
 @settings(**_FUZZ_SETTINGS)
 @given(
diff --git a/tests/api/test_repository.py b/tests/api/test_repository.py
index 12d7bb8..3b0d31b 100644
--- a/tests/api/test_repository.py
+++ b/tests/api/test_repository.py
@@ -5,7 +5,9 @@ covering DEBT-006 (zero test coverage on the database layer).
 """
 import json
 import pytest
+from hypothesis import given, settings, strategies as st
 from decnet.web.db.sqlite.repository import SQLiteRepository
+from .conftest import _FUZZ_SETTINGS
 
 
 @pytest.fixture
@@ -172,3 +174,27 @@ async def test_user_lifecycle(repo):
     updated = await repo.get_user_by_uuid(uid)
     assert updated["password_hash"] == "new_hashed_pw"
     assert updated["must_change_password"] == 0
+
+
+@pytest.mark.fuzz
+@pytest.mark.anyio
+@settings(**_FUZZ_SETTINGS)
+@given(
+    raw_line=st.text(max_size=2048),
+    fields=st.text(max_size=2048),
+    attacker_ip=st.text(max_size=128),
+)
+async def test_fuzz_add_log(repo, raw_line: str, fields: str, attacker_ip: str) -> None:
+    """Fuzz add_log with arbitrary strings — must never raise uncaught exceptions."""
+    try:
+        await repo.add_log({
+            "decky": "fuzz-decky",
+            "service": "ssh",
+            "event_type": "connect",
+            "attacker_ip": attacker_ip,
+            "raw_line": raw_line,
+            "fields": fields,
+            "msg": "",
+        })
+    except Exception as exc:
+        pytest.fail(f"add_log raised unexpectedly: {exc}")
diff --git a/tests/api/test_schemathesis.py b/tests/api/test_schemathesis.py
index 310f3da..4cab4ee 100644
--- a/tests/api/test_schemathesis.py
+++ b/tests/api/test_schemathesis.py
@@ -10,6 +10,7 @@ replace the checks list with the default (remove the argument) for full complian
 
 Requires DECNET_DEVELOPER=true (set in tests/conftest.py) to expose /openapi.json.
 """
+import pytest
 import schemathesis
 from hypothesis import settings
 from schemathesis.checks import not_a_server_error
@@ -18,6 +19,7 @@ from decnet.web.api import app
 schema = schemathesis.openapi.from_asgi("/openapi.json", app)
 
 
+@pytest.mark.fuzz
 @schemathesis.pytest.parametrize(api=schema)
 @settings(max_examples=5, deadline=None)
 def test_schema_compliance(case):