Expanded integration coverage and enforced test categories.

tests/integration/cli/__init__.py

@@ -0,0 +1,15 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""CLI integration tests for Crabstero."""

tests/integration/cli/test_systemd_notify.py

@@ -0,0 +1,89 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Integration tests for systemd notification socket behavior."""
+
+import logging
+import os
+import socket
+import sys
+from typing import TYPE_CHECKING
+
+import pytest
+
+from crabstero.cli import _sd_notify
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+pytestmark = pytest.mark.skipif(
+    os.name != "posix" or not hasattr(socket, "AF_UNIX"),
+    reason="systemd notification sockets require Unix-domain socket support",
+)
+
+
+class TestSystemdNotifySocket:
+    """Systemd notification helper behavior against real Unix-domain sockets."""
+
+    def test_sd_notify_sends_datagram(
+        self,
+        tmp_path: Path,
+        monkeypatch: pytest.MonkeyPatch,
+    ) -> None:
+        """_sd_notify sends the payload to NOTIFY_SOCKET."""
+        socket_path = tmp_path / "notify.sock"
+
+        with socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM) as server:
+            server.bind(str(socket_path))
+            server.settimeout(1)
+            monkeypatch.setenv("NOTIFY_SOCKET", str(socket_path))
+
+            _sd_notify("READY=1")
+
+            assert server.recv(1024) == b"READY=1"
+
+    def test_sd_notify_ignores_socket_errors(
+        self,
+        tmp_path: Path,
+        monkeypatch: pytest.MonkeyPatch,
+        caplog: pytest.LogCaptureFixture,
+    ) -> None:
+        """_sd_notify logs and suppresses notification socket send failures."""
+        monkeypatch.setenv("NOTIFY_SOCKET", str(tmp_path / "missing.sock"))
+
+        with caplog.at_level(logging.DEBUG, logger="crabstero"):
+            _sd_notify("READY=1")
+
+        assert "Could not send systemd notification" in caplog.text
+
+    @pytest.mark.skipif(
+        sys.platform != "linux",
+        reason="abstract Unix sockets are Linux-specific",
+    )
+    def test_sd_notify_sends_to_abstract_socket(
+        self,
+        monkeypatch: pytest.MonkeyPatch,
+    ) -> None:
+        """@-prefixed NOTIFY_SOCKET values target Linux abstract sockets."""
+        socket_name = f"crabstero-notify-{os.getpid()}"
+
+        with socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM) as server:
+            server.bind(f"\0{socket_name}")
+            server.settimeout(1)
+            monkeypatch.setenv("NOTIFY_SOCKET", f"@{socket_name}")
+
+            _sd_notify("READY=1")
+
+            assert server.recv(1024) == b"READY=1"

tests/integration/database/__init__.py

@@ -0,0 +1,15 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Database integration tests for Crabstero."""

tests/integration/database/conftest.py

@@ -0,0 +1,35 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Fixtures used only by database-bound integration tests."""
+
+from typing import TYPE_CHECKING
+
+import pytest
+
+from crabstero.database import Database
+
+if TYPE_CHECKING:
+    from collections.abc import AsyncGenerator
+    from pathlib import Path
+
+
+@pytest.fixture
+async def db(tmp_path: Path) -> AsyncGenerator[Database]:
+    """Yield an isolated file-backed database for SQLite integration tests."""
+    database = await Database.connect(str(tmp_path / "crabstero.db"))
+    try:
+        yield database
+    finally:
+        await database.close()

tests/integration/database/test_database.py

@@ -0,0 +1,645 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Integration tests for the Database class.
+
+Tests cover Database.connect (pragmas, schema), markov start word and
+transition CRUD, image storage, flag CRUD, and channel ingestion tracking.
+"""
+
+from typing import TYPE_CHECKING
+
+import pytest
+
+from crabstero.database import ChannelImage, Database, StartWord, Transition
+from crabstero.flags import EntityType, Flag
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+class TestConnect:
+    """Database.connect creates a configured SQLite database."""
+
+    async def test_synchronous_normal(self, db: Database) -> None:
+        """Synchronous mode is set to NORMAL."""
+        async with db._connection.execute("PRAGMA synchronous") as cursor:
+            row = await cursor.fetchone()
+        assert row is not None
+        assert row[0] == 1
+
+    async def test_schema_creates_tables(self, db: Database) -> None:
+        """All expected tables exist after connect."""
+        async with db._connection.execute(
+            "SELECT name FROM sqlite_master WHERE type = 'table' ORDER BY name",
+        ) as cursor:
+            tables = [row[0] for row in await cursor.fetchall()]
+        assert tables == [
+            "channel_images",
+            "flags",
+            "ingested_channels",
+            "markov_start_words",
+            "markov_transitions",
+        ]
+
+
+class TestAddMarkovData:
+    """Markov start word and transition storage via add_markov_data."""
+
+    async def test_stores_start_word(self, db: Database) -> None:
+        """Inserted start word can be retrieved by channel."""
+        await db.add_markov_data([StartWord(1, 100, "Hello")], [])
+        result = await db.get_random_start_word(1)
+        assert result == "Hello"
+
+    async def test_stores_transition(self, db: Database) -> None:
+        """Inserted transition can be retrieved by channel and word."""
+        await db.add_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        result = await db.get_random_next_word(1, "Hello")
+        assert result == "world."
+
+    async def test_stores_both_in_single_call(self, db: Database) -> None:
+        """Start words and transitions are stored in a single call."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Hello")],
+            [Transition(1, 100, "Hello", "world.")],
+        )
+        assert await db.get_random_start_word(1) == "Hello"
+        assert await db.get_random_next_word(1, "Hello") == "world."
+
+    async def test_empty_lists_is_noop(self, db: Database) -> None:
+        """Empty lists do not store any data."""
+        await db.add_markov_data([], [])
+        assert await db.get_random_start_word(1) is None
+
+
+class TestMarkovReadMethods:
+    """Markov read methods return None for out-of-scope or missing data."""
+
+    async def test_returns_none_when_empty(self, db: Database) -> None:
+        """Returns None when no data has been stored."""
+        assert await db.get_random_start_word(1) is None
+        assert await db.get_random_next_word(1, "nonexistent") is None
+        assert await db.get_random_completing_next_word(1, "nonexistent") is None
+
+    async def test_start_word_scoped_to_channel(self, db: Database) -> None:
+        """A start word in one channel is not returned for another channel."""
+        await db.add_markov_data([StartWord(1, 100, "Hello")], [])
+        assert await db.get_random_start_word(2) is None
+
+    async def test_next_word_scoped_to_channel(self, db: Database) -> None:
+        """A transition in one channel is not returned for another channel."""
+        await db.add_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(2, "Hello") is None
+
+    async def test_completing_next_word_scoped_to_channel(self, db: Database) -> None:
+        """Completing transition is not returned for another channel."""
+        await db.add_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_completing_next_word(2, "Hello") is None
+
+    async def test_next_word_scoped_to_word(self, db: Database) -> None:
+        """A transition for one word is not returned when querying a different word."""
+        await db.add_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(1, "Goodbye") is None
+
+    async def test_completing_next_word_scoped_to_word(self, db: Database) -> None:
+        """Completing transition is not returned for a different word."""
+        await db.add_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_completing_next_word(1, "Goodbye") is None
+
+    @pytest.mark.parametrize(
+        "completing_word",
+        [
+            pytest.param("world.", id="period"),
+            pytest.param("world!", id="exclamation"),
+            pytest.param("world?", id="question"),
+            pytest.param("world\u00a7", id="section-sign"),
+        ],
+    )
+    async def test_completing_word_filters_punctuation(
+        self,
+        db: Database,
+        completing_word: str,
+    ) -> None:
+        """get_random_completing_next_word only returns sentence-ending words."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "beautiful"),
+                Transition(1, 100, "Hello", completing_word),
+            ],
+        )
+        for _ in range(100):
+            result = await db.get_random_completing_next_word(1, "Hello")
+            assert result == completing_word
+
+    async def test_completing_returns_none_without_match(self, db: Database) -> None:
+        """Returns None when no transitions end with sentence punctuation."""
+        await db.add_markov_data([], [Transition(1, 100, "Hello", "beautiful")])
+        result = await db.get_random_completing_next_word(1, "Hello")
+        assert result is None
+
+    async def test_start_word_pooled_across_users(self, db: Database) -> None:
+        """Start words from different users are visible in the same channel query."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Hello"), StartWord(1, 200, "Goodbye")],
+            [],
+        )
+        assert await db.get_random_start_word(1) in {"Hello", "Goodbye"}
+
+    async def test_next_word_pooled_across_users(self, db: Database) -> None:
+        """Transitions from different users are visible in the same channel query."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "world."),
+                Transition(1, 200, "Hello", "friend."),
+            ],
+        )
+        assert await db.get_random_next_word(1, "Hello") in {"world.", "friend."}
+
+    async def test_completing_next_word_pooled_across_users(self, db: Database) -> None:
+        """Completing transitions from different users are visible."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "world."),
+                Transition(1, 200, "Hello", "friend."),
+            ],
+        )
+        assert await db.get_random_completing_next_word(1, "Hello") in {
+            "world.",
+            "friend.",
+        }
+
+
+class TestRemoveMarkovData:
+    """Markov data removal via remove_markov_data."""
+
+    async def test_removes_one_start_word(self, db: Database) -> None:
+        """Removes exactly one matching start word row."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Hello"), StartWord(1, 100, "Hello")],
+            [],
+        )
+        await db.remove_markov_data([StartWord(1, 100, "Hello")], [])
+        # One copy should remain.
+        assert await db.get_random_start_word(1) == "Hello"
+
+    async def test_removes_one_transition(self, db: Database) -> None:
+        """Removes exactly one matching transition row."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "world."),
+                Transition(1, 100, "Hello", "world."),
+            ],
+        )
+        await db.remove_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(1, "Hello") == "world."
+
+    async def test_removes_last_start_word(self, db: Database) -> None:
+        """Removing the only start word leaves the table empty for that channel."""
+        await db.add_markov_data([StartWord(1, 100, "Hello")], [])
+        await db.remove_markov_data([StartWord(1, 100, "Hello")], [])
+        assert await db.get_random_start_word(1) is None
+
+    async def test_removes_last_transition(self, db: Database) -> None:
+        """Removing the only transition leaves no next word."""
+        await db.add_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        await db.remove_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(1, "Hello") is None
+
+    async def test_no_match_is_noop(self, db: Database) -> None:
+        """Removing a non-existent row does not raise."""
+        await db.remove_markov_data(
+            [StartWord(1, 100, "nope")],
+            [Transition(1, 100, "nope", "nah")],
+        )
+
+    async def test_start_word_removal_scoped_to_channel(self, db: Database) -> None:
+        """Removing a start word in one channel leaves another channel intact."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Hello"), StartWord(2, 200, "Hello")],
+            [],
+        )
+        await db.remove_markov_data([StartWord(1, 100, "Hello")], [])
+        assert await db.get_random_start_word(1) is None
+        assert await db.get_random_start_word(2) == "Hello"
+
+    async def test_transition_removal_scoped_to_channel(self, db: Database) -> None:
+        """Removing a transition in one channel leaves another channel intact."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "world."),
+                Transition(2, 200, "Hello", "world."),
+            ],
+        )
+        await db.remove_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(1, "Hello") is None
+        assert await db.get_random_next_word(2, "Hello") == "world."
+
+    async def test_start_word_removal_scoped_to_user(self, db: Database) -> None:
+        """Removing a start word for one user leaves another user."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Hello"), StartWord(1, 200, "Hello")],
+            [],
+        )
+        await db.remove_markov_data([StartWord(1, 100, "Hello")], [])
+        assert await db.get_random_start_word(1) == "Hello"
+
+    async def test_transition_removal_scoped_to_user(self, db: Database) -> None:
+        """Removing a transition for one user leaves another user."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "world."),
+                Transition(1, 200, "Hello", "world."),
+            ],
+        )
+        await db.remove_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(1, "Hello") == "world."
+
+    async def test_start_word_removal_scoped_to_word(self, db: Database) -> None:
+        """Removing one start word leaves a different start word."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Hello"), StartWord(1, 100, "World")],
+            [],
+        )
+        await db.remove_markov_data([StartWord(1, 100, "Hello")], [])
+        assert await db.get_random_start_word(1) == "World"
+
+    async def test_transition_removal_scoped_to_word(self, db: Database) -> None:
+        """Removing one word's transition leaves another word's."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "world."),
+                Transition(1, 100, "Goodbye", "world."),
+            ],
+        )
+        await db.remove_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(1, "Hello") is None
+        assert await db.get_random_next_word(1, "Goodbye") == "world."
+
+    async def test_transition_removal_scoped_to_next_word(self, db: Database) -> None:
+        """Removing one next_word leaves a different next_word."""
+        await db.add_markov_data(
+            [],
+            [
+                Transition(1, 100, "Hello", "world."),
+                Transition(1, 100, "Hello", "friend."),
+            ],
+        )
+        await db.remove_markov_data([], [Transition(1, 100, "Hello", "world.")])
+        assert await db.get_random_next_word(1, "Hello") == "friend."
+
+    async def test_empty_lists_is_noop(self, db: Database) -> None:
+        """Empty lists do not error."""
+        await db.remove_markov_data([], [])
+
+
+class TestImages:
+    """Image URL storage and random retrieval."""
+
+    async def test_add_and_retrieve(self, db: Database) -> None:
+        """Inserted image URL can be retrieved by channel."""
+        await db.add_images([ChannelImage(1, 100, "https://example.com/cat.png")])
+        result = await db.get_random_image(1)
+        assert result == "https://example.com/cat.png"
+
+    async def test_returns_none_when_empty(self, db: Database) -> None:
+        """Returns None for a channel with no images."""
+        result = await db.get_random_image(999)
+        assert result is None
+
+    async def test_image_scoped_to_channel(self, db: Database) -> None:
+        """An image in one channel is not returned for another channel."""
+        await db.add_images([ChannelImage(1, 100, "https://example.com/cat.png")])
+        assert await db.get_random_image(2) is None
+
+    async def test_empty_list_is_noop(self, db: Database) -> None:
+        """Empty list does not store any data."""
+        await db.add_images([])
+        assert await db.get_random_image(1) is None
+
+    async def test_image_pooled_across_users(self, db: Database) -> None:
+        """Images from different users are visible in the same channel query."""
+        await db.add_images(
+            [
+                ChannelImage(1, 100, "https://example.com/a.png"),
+                ChannelImage(1, 200, "https://example.com/b.png"),
+            ],
+        )
+        assert await db.get_random_image(1) in {
+            "https://example.com/a.png",
+            "https://example.com/b.png",
+        }
+
+
+class TestRemoveImages:
+    """Image removal via remove_images."""
+
+    async def test_removes_one_image(self, db: Database) -> None:
+        """Removes exactly one matching image row."""
+        await db.add_images(
+            [
+                ChannelImage(1, 100, "https://example.com/a.png"),
+                ChannelImage(1, 100, "https://example.com/a.png"),
+            ],
+        )
+        await db.remove_images([ChannelImage(1, 100, "https://example.com/a.png")])
+        # One copy should remain.
+        assert await db.get_random_image(1) == "https://example.com/a.png"
+
+    async def test_removes_last_image(self, db: Database) -> None:
+        """Removing the only image leaves none for that channel."""
+        await db.add_images([ChannelImage(1, 100, "https://example.com/a.png")])
+        await db.remove_images([ChannelImage(1, 100, "https://example.com/a.png")])
+        assert await db.get_random_image(1) is None
+
+    async def test_image_removal_scoped_to_channel(self, db: Database) -> None:
+        """Removing an image in one channel leaves another channel intact."""
+        await db.add_images(
+            [
+                ChannelImage(1, 100, "https://example.com/a.png"),
+                ChannelImage(2, 200, "https://example.com/a.png"),
+            ],
+        )
+        await db.remove_images([ChannelImage(1, 100, "https://example.com/a.png")])
+        assert await db.get_random_image(1) is None
+        assert await db.get_random_image(2) == "https://example.com/a.png"
+
+    async def test_image_removal_scoped_to_user(self, db: Database) -> None:
+        """Removing an image for one user leaves another user."""
+        await db.add_images(
+            [
+                ChannelImage(1, 100, "https://example.com/a.png"),
+                ChannelImage(1, 200, "https://example.com/a.png"),
+            ],
+        )
+        await db.remove_images([ChannelImage(1, 100, "https://example.com/a.png")])
+        assert await db.get_random_image(1) == "https://example.com/a.png"
+
+    async def test_image_removal_scoped_to_url(self, db: Database) -> None:
+        """Removing one URL leaves a different URL for the same user."""
+        await db.add_images(
+            [
+                ChannelImage(1, 100, "https://example.com/a.png"),
+                ChannelImage(1, 100, "https://example.com/b.png"),
+            ],
+        )
+        await db.remove_images([ChannelImage(1, 100, "https://example.com/a.png")])
+        assert await db.get_random_image(1) == "https://example.com/b.png"
+
+    async def test_no_match_is_noop(self, db: Database) -> None:
+        """Removing a non-existent image does not raise."""
+        await db.remove_images([ChannelImage(1, 100, "https://example.com/nope.png")])
+
+    async def test_empty_list_is_noop(self, db: Database) -> None:
+        """Empty list does not error."""
+        await db.remove_images([])
+
+
+class TestFlags:
+    """Flag CRUD operations on entities."""
+
+    async def test_set_and_check(self, db: Database) -> None:
+        """A set flag is reported as set."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.CHANNEL, "123", Flag.NO_REPLY) is True
+
+    async def test_unset_flag_is_false(self, db: Database) -> None:
+        """An unset flag is reported as not set."""
+        assert await db.is_flag_set(EntityType.CHANNEL, "123", Flag.NO_REPLY) is False
+
+    async def test_clear_flag(self, db: Database) -> None:
+        """A cleared flag is no longer reported as set."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        await db.clear_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.CHANNEL, "123", Flag.NO_REPLY) is False
+
+    async def test_set_idempotent(self, db: Database) -> None:
+        """Setting the same flag twice does not raise."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.CHANNEL, "123", Flag.NO_REPLY) is True
+
+    async def test_scoped_to_entity_id(self, db: Database) -> None:
+        """A flag set on one entity is not visible on another entity."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.CHANNEL, "456", Flag.NO_REPLY) is False
+
+    async def test_scoped_to_entity_type(self, db: Database) -> None:
+        """A flag set on one entity type is not visible on another."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.USER, "123", Flag.NO_REPLY) is False
+
+    async def test_scoped_to_flag_name(self, db: Database) -> None:
+        """A flag set under one name is not visible under a different name."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.CHANNEL, "123", Flag.NO_INGEST) is False
+
+    async def test_clear_scoped_to_flag_name(self, db: Database) -> None:
+        """Clearing one flag leaves other flags on the same entity intact."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_INGEST)
+        await db.clear_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.CHANNEL, "123", Flag.NO_INGEST) is True
+
+    async def test_clear_scoped_to_entity_id(self, db: Database) -> None:
+        """Clearing a flag on one entity leaves another entity."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        await db.set_flag(EntityType.CHANNEL, "456", Flag.NO_REPLY)
+        await db.clear_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.CHANNEL, "456", Flag.NO_REPLY) is True
+
+    async def test_clear_scoped_to_entity_type(self, db: Database) -> None:
+        """Clearing a flag on one entity type leaves another type."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        await db.set_flag(EntityType.USER, "123", Flag.NO_REPLY)
+        await db.clear_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        assert await db.is_flag_set(EntityType.USER, "123", Flag.NO_REPLY) is True
+
+    async def test_clear_unset_flag_is_noop(self, db: Database) -> None:
+        """Clearing a flag that was never set does not raise or affect other flags."""
+        await db.set_flag(EntityType.CHANNEL, "123", Flag.NO_REPLY)
+        await db.clear_flag(EntityType.CHANNEL, "123", Flag.NO_INGEST)
+        assert await db.is_flag_set(EntityType.CHANNEL, "123", Flag.NO_REPLY) is True
+
+
+class TestChannelIngestion:
+    """Channel ingestion tracking."""
+
+    async def test_mark_and_check(self, db: Database) -> None:
+        """A marked channel is reported as ingested."""
+        await db.mark_channel_ingested(42)
+        assert await db.is_channel_ingested(42) is True
+
+    async def test_not_ingested_by_default(self, db: Database) -> None:
+        """Unmarked channels are not reported as ingested."""
+        assert await db.is_channel_ingested(42) is False
+
+    async def test_mark_idempotent(self, db: Database) -> None:
+        """Marking the same channel twice does not raise."""
+        await db.mark_channel_ingested(42)
+        await db.mark_channel_ingested(42)
+        assert await db.is_channel_ingested(42) is True
+
+    async def test_scoped_to_channel(self, db: Database) -> None:
+        """Marking one channel as ingested does not affect another channel."""
+        await db.mark_channel_ingested(42)
+        assert await db.is_channel_ingested(99) is False
+
+
+class TestTransactionRollback:
+    """Transaction rolls back all changes on error."""
+
+    async def test_error_rolls_back_insert(self, db: Database) -> None:
+        """An error during a transaction prevents partial data from persisting."""
+
+        async def insert_and_fail() -> None:
+            async with db._transaction():
+                await db._connection.execute(
+                    "INSERT INTO markov_start_words"
+                    " (channel_id, user_id, word)"
+                    " VALUES (?, ?, ?)",
+                    (1, 100, "should_not_persist"),
+                )
+                msg = "simulated failure"
+                raise RuntimeError(msg)
+
+        with pytest.raises(RuntimeError, match="simulated"):
+            await insert_and_fail()
+        assert await db.get_random_start_word(1) is None
+
+
+class TestForgetUser:
+    """Atomic forget-user transaction across all tables."""
+
+    async def test_deletes_data_and_sets_no_ingest(self, db: Database) -> None:
+        """All user data is removed and noIngest flag is set."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Hello")],
+            [Transition(1, 100, "Hello", "world.")],
+        )
+        await db.add_images([ChannelImage(1, 100, "https://example.com/a.png")])
+        await db.set_flag(EntityType.USER, "100", Flag.ALLOW_PINGS)
+
+        await db.forget_user(100, Flag.NO_INGEST)
+
+        assert await db.get_random_start_word(1) is None
+        assert await db.get_random_next_word(1, "Hello") is None
+        assert await db.get_random_image(1) is None
+        assert await db.is_flag_set(EntityType.USER, "100", Flag.ALLOW_PINGS) is False
+        assert await db.is_flag_set(EntityType.USER, "100", Flag.NO_INGEST) is True
+
+    async def test_preserves_other_users(self, db: Database) -> None:
+        """Data belonging to other users is not affected."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "Gone"), StartWord(1, 200, "Keep")],
+            [
+                Transition(1, 100, "Gone", "away."),
+                Transition(1, 200, "Keep", "this."),
+            ],
+        )
+        await db.add_images(
+            [
+                ChannelImage(1, 100, "https://example.com/gone.png"),
+                ChannelImage(1, 200, "https://example.com/stay.png"),
+            ],
+        )
+        await db.set_flag(EntityType.USER, "200", Flag.ALLOW_PINGS)
+
+        await db.forget_user(100, Flag.NO_INGEST)
+
+        assert await db.get_random_start_word(1) == "Keep"
+        assert await db.get_random_next_word(1, "Keep") == "this."
+        assert await db.get_random_image(1) == "https://example.com/stay.png"
+        assert await db.is_flag_set(EntityType.USER, "200", Flag.ALLOW_PINGS) is True
+
+    async def test_preserves_other_entity_type_flags(self, db: Database) -> None:
+        """Flags on channels with the same entity ID are not affected."""
+        await db.set_flag(EntityType.CHANNEL, "100", Flag.NO_REPLY)
+        await db.set_flag(EntityType.USER, "100", Flag.NO_REPLY)
+
+        await db.forget_user(100, Flag.NO_INGEST)
+
+        assert await db.is_flag_set(EntityType.CHANNEL, "100", Flag.NO_REPLY) is True
+        assert await db.is_flag_set(EntityType.USER, "100", Flag.NO_REPLY) is False
+
+    async def test_clears_existing_flags_except_no_ingest(self, db: Database) -> None:
+        """Existing user flags are cleared but noIngest remains."""
+        await db.set_flag(EntityType.USER, "100", Flag.NO_REPLY)
+        await db.set_flag(EntityType.USER, "100", Flag.ALLOW_PINGS)
+
+        await db.forget_user(100, Flag.NO_INGEST)
+
+        assert await db.is_flag_set(EntityType.USER, "100", Flag.NO_REPLY) is False
+        assert await db.is_flag_set(EntityType.USER, "100", Flag.ALLOW_PINGS) is False
+        assert await db.is_flag_set(EntityType.USER, "100", Flag.NO_INGEST) is True
+
+    async def test_deletes_across_channels(self, db: Database) -> None:
+        """All user data is removed from every channel."""
+        await db.add_markov_data(
+            [StartWord(1, 100, "One"), StartWord(2, 100, "Two")],
+            [
+                Transition(1, 100, "One", "fish."),
+                Transition(2, 100, "Two", "fish."),
+            ],
+        )
+        await db.add_images(
+            [
+                ChannelImage(1, 100, "https://example.com/a.png"),
+                ChannelImage(2, 100, "https://example.com/b.png"),
+            ],
+        )
+
+        await db.forget_user(100, Flag.NO_INGEST)
+
+        assert await db.get_random_start_word(1) is None
+        assert await db.get_random_start_word(2) is None
+        assert await db.get_random_next_word(1, "One") is None
+        assert await db.get_random_next_word(2, "Two") is None
+        assert await db.get_random_image(1) is None
+        assert await db.get_random_image(2) is None
+
+    async def test_noop_for_nonexistent_user(self, db: Database) -> None:
+        """Forgetting a user with no data does not raise."""
+        await db.forget_user(999, Flag.NO_INGEST)
+        assert await db.is_flag_set(EntityType.USER, "999", Flag.NO_INGEST) is True
+
+
+class TestWriteDurability:
+    """Writes persist across close and reopen."""
+
+    async def test_markov_data_survives_reopen(self, tmp_path: Path) -> None:
+        """Data written via add_markov_data is durable after close/reopen."""
+        db_path = str(tmp_path / "durability.db")
+        db = await Database.connect(db_path)
+        try:
+            await db.add_markov_data(
+                [StartWord(1, 100, "Hello")],
+                [Transition(1, 100, "Hello", "world.")],
+            )
+        finally:
+            await db.close()
+
+        db2 = await Database.connect(db_path)
+        try:
+            assert await db2.get_random_start_word(1) == "Hello"
+            assert await db2.get_random_next_word(1, "Hello") == "world."
+        finally:
+            await db2.close()

tests/integration/database/test_ingest_uningest.py

@@ -14,8 +14,10 @@
 
 """Integration tests for the full ingest → uningest cycle."""
 
+from collections.abc import Awaitable, Callable
 from typing import TYPE_CHECKING
 
+import aiosqlite
 import pytest
 
 from crabstero.cache import CachedMessage, IngestCache
@@ -24,18 +26,31 @@ from crabstero.markov import ingest, uningest
 from crabstero.messages import uningest_message
 
 if TYPE_CHECKING:
-    import aiosqlite
-
     from crabstero.database import Database
 
+type SnapshotRows = Callable[["Database"], Awaitable[dict[str, list[aiosqlite.Row]]]]
 
-async def _snapshot(db: Database) -> dict[str, list[aiosqlite.Row]]:
-    """Return sorted rows from all Markov-related tables."""
-    tables: dict[str, list[aiosqlite.Row]] = {}
-    for table in ("markov_start_words", "markov_transitions", "channel_images"):
-        async with db._connection.execute(f"SELECT * FROM {table}") as cursor:  # noqa: S608
-            tables[table] = sorted(await cursor.fetchall())
-    return tables
+
+@pytest.fixture
+def snapshot_rows() -> SnapshotRows:
+    """Return a snapshot reader for Markov and image tables."""
+
+    async def read(db: Database) -> dict[str, list[aiosqlite.Row]]:
+        tables: dict[str, list[aiosqlite.Row]] = {}
+        for table in ("markov_start_words", "markov_transitions", "channel_images"):
+            async with db._connection.execute(
+                f"SELECT * FROM {table}",  # noqa: S608
+            ) as cursor:
+                tables[table] = sorted(await cursor.fetchall())
+        return tables
+
+    return read
+
+
+@pytest.fixture
+def ingest_cache() -> IngestCache:
+    """Return an empty ingest cache for uningest-message tests."""
+    return IngestCache()
 
 
 class TestIngestUningestCycle:
@@ -114,12 +129,17 @@ class TestUningestRestoresState:
             ),
         ],
     )
-    async def test_uningest_restores_empty_db(self, db: Database, text: str) -> None:
+    async def test_uningest_restores_empty_db(
+        self,
+        db: Database,
+        text: str,
+        snapshot_rows: SnapshotRows,
+    ) -> None:
         """Ingest then uningest on an empty database leaves all tables empty."""
-        before = await _snapshot(db)
+        before = await snapshot_rows(db)
         await ingest(db, 1, 100, text)
         await uningest(db, 1, 100, text)
-        after = await _snapshot(db)
+        after = await snapshot_rows(db)
         assert after == before
 
     @pytest.mark.parametrize(
@@ -136,26 +156,26 @@ class TestUningestRestoresState:
         self,
         db: Database,
         text: str,
+        snapshot_rows: SnapshotRows,
     ) -> None:
         """Ingest then uningest preserves unrelated pre-existing data exactly."""
         await ingest(db, 99, 200, "Pre-existing data stays safe.")
         await db.add_images([ChannelImage(99, 200, "https://example.com/existing.png")])
 
-        before = await _snapshot(db)
+        before = await snapshot_rows(db)
         await ingest(db, 1, 100, text)
         await uningest(db, 1, 100, text)
-        after = await _snapshot(db)
+        after = await snapshot_rows(db)
         assert after == before
 
 
 class TestUningestMessage:
     """Orchestrated uningest via cache lookup and database reversal."""
 
-    async def test_content_only(self, db: Database) -> None:
+    async def test_content_only(self, db: Database, ingest_cache: IngestCache) -> None:
         """Uningest reverses a content-only message via the cache."""
         await ingest(db, 1, 100, "Hello beautiful world.")
-        cache = IngestCache()
-        cache.put(
+        ingest_cache.put(
             555,
             CachedMessage(
                 channel_id=1,
@@ -166,17 +186,16 @@ class TestUningestMessage:
             ),
         )
 
-        await uningest_message(db, cache, 555)
+        await uningest_message(db, ingest_cache, 555)
 
         assert await db.get_random_start_word(1) is None
         assert await db.get_random_next_word(1, "Hello") is None
 
-    async def test_embeds_only(self, db: Database) -> None:
+    async def test_embeds_only(self, db: Database, ingest_cache: IngestCache) -> None:
         """Uningest reverses embed text ingestion."""
         await ingest(db, 1, 100, "Embed title here.")
         await ingest(db, 1, 100, "Embed description here.")
-        cache = IngestCache()
-        cache.put(
+        ingest_cache.put(
             556,
             CachedMessage(
                 channel_id=1,
@@ -187,17 +206,20 @@ class TestUningestMessage:
             ),
         )
 
-        await uningest_message(db, cache, 556)
+        await uningest_message(db, ingest_cache, 556)
 
         assert await db.get_random_start_word(1) is None
 
-    async def test_content_with_embeds_and_images(self, db: Database) -> None:
+    async def test_content_with_embeds_and_images(
+        self,
+        db: Database,
+        ingest_cache: IngestCache,
+    ) -> None:
         """Uningest reverses content, embed text, and image data together."""
         await ingest(db, 1, 100, "Body text here.")
         await ingest(db, 1, 100, "Embed title.")
         await db.add_images([ChannelImage(1, 100, "https://example.com/img.png")])
-        cache = IngestCache()
-        cache.put(
+        ingest_cache.put(
             557,
             CachedMessage(
                 channel_id=1,
@@ -208,28 +230,35 @@ class TestUningestMessage:
             ),
         )
 
-        await uningest_message(db, cache, 557)
+        await uningest_message(db, ingest_cache, 557)
 
         assert await db.get_random_start_word(1) is None
         assert await db.get_random_image(1) is None
 
-    async def test_cache_miss_is_noop(self, db: Database) -> None:
+    async def test_cache_miss_is_noop(
+        self,
+        db: Database,
+        ingest_cache: IngestCache,
+        snapshot_rows: SnapshotRows,
+    ) -> None:
         """A message not in the cache leaves the database unchanged."""
         await ingest(db, 1, 100, "Keep this data.")
-        cache = IngestCache()
-        before = await _snapshot(db)
+        before = await snapshot_rows(db)
 
-        await uningest_message(db, cache, 999)
+        await uningest_message(db, ingest_cache, 999)
 
-        after = await _snapshot(db)
+        after = await snapshot_rows(db)
         assert after == before
 
-    async def test_preserves_other_messages(self, db: Database) -> None:
+    async def test_preserves_other_messages(
+        self,
+        db: Database,
+        ingest_cache: IngestCache,
+    ) -> None:
         """Uningesting one message leaves another message's data intact."""
         await ingest(db, 1, 100, "First message.")
         await ingest(db, 1, 100, "Second message.")
-        cache = IngestCache()
-        cache.put(
+        ingest_cache.put(
             601,
             CachedMessage(
                 channel_id=1,
@@ -240,16 +269,19 @@ class TestUningestMessage:
             ),
         )
 
-        await uningest_message(db, cache, 601)
+        await uningest_message(db, ingest_cache, 601)
 
         assert await db.get_random_start_word(1) == "Second"
         assert await db.get_random_next_word(1, "Second") == "message."
 
-    async def test_pops_entry_from_cache(self, db: Database) -> None:
+    async def test_pops_entry_from_cache(
+        self,
+        db: Database,
+        ingest_cache: IngestCache,
+    ) -> None:
         """The cache entry is consumed after uningest."""
         await ingest(db, 1, 100, "Hello world.")
-        cache = IngestCache()
-        cache.put(
+        ingest_cache.put(
             602,
             CachedMessage(
                 channel_id=1,
@@ -260,6 +292,6 @@ class TestUningestMessage:
             ),
         )
 
-        await uningest_message(db, cache, 602)
+        await uningest_message(db, ingest_cache, 602)
 
-        assert cache.pop(602) is None
+        assert ingest_cache.pop(602) is None

tests/integration/discord/__init__.py

@@ -0,0 +1,15 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Discord-boundary integration tests."""

tests/integration/discord/conftest.py

@@ -0,0 +1,129 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Fixtures used only by Simcord-backed Discord integration tests."""
+
+from collections.abc import Awaitable, Callable
+from dataclasses import dataclass
+from typing import TYPE_CHECKING
+
+import pytest
+
+from crabstero.bot import Crabstero
+from crabstero.database import Database
+
+if TYPE_CHECKING:
+    from collections.abc import AsyncGenerator
+    from pathlib import Path
+
+    from simcord import ChannelHandle, Env, GuildHandle, MemberActor
+
+type StartWordsForChannel = Callable[[Database, int], Awaitable[list[str]]]
+type MakeSimcordTextChannel = Callable[["Env"], Awaitable["SimcordTextChannel"]]
+type MakeSimcordMemberChannel = Callable[["Env"], Awaitable["SimcordMemberChannel"]]
+
+
+@dataclass(frozen=True, slots=True)
+class SimcordTextChannel:
+    """Guild and text channel created inside a running Simcord environment."""
+
+    guild: GuildHandle
+    channel: ChannelHandle
+
+
+@dataclass(frozen=True, slots=True)
+class SimcordMemberChannel:
+    """Guild, text channel, and human member for Discord flow tests."""
+
+    guild: GuildHandle
+    member: MemberActor
+    channel: ChannelHandle
+
+
+@pytest.fixture
+async def crabstero_bot(tmp_path: Path) -> AsyncGenerator[Crabstero]:
+    """Yield the Crabstero bot instance inspected by Discord integration tests."""
+    bot = Crabstero(str(tmp_path / "crabstero.db"))
+    try:
+        yield bot
+    finally:
+        bot.ws = None  # type: ignore[assignment]
+        await bot.close()
+
+
+@pytest.fixture
+def simcord_bot(crabstero_bot: Crabstero) -> Crabstero:
+    """Expose Crabstero under the fixture name required by Simcord."""
+    return crabstero_bot
+
+
+@pytest.fixture
+def make_simcord_text_channel() -> MakeSimcordTextChannel:
+    """Return a factory for guild text channels in any Simcord environment."""
+
+    async def make(env: Env) -> SimcordTextChannel:
+        guild = env.create_guild()
+        await env.settle()
+        channel = guild.create_text_channel("general")
+        await env.settle()
+        return SimcordTextChannel(guild, channel)
+
+    return make
+
+
+@pytest.fixture
+async def simcord_text_channel(
+    simcord_env: Env,
+    make_simcord_text_channel: MakeSimcordTextChannel,
+) -> SimcordTextChannel:
+    """Create one guild text channel in the default Simcord environment."""
+    return await make_simcord_text_channel(simcord_env)
+
+
+@pytest.fixture
+def make_simcord_member_channel() -> MakeSimcordMemberChannel:
+    """Return a factory for guild/member/channel triples in any Simcord env."""
+
+    async def make(env: Env) -> SimcordMemberChannel:
+        guild = env.create_guild()
+        await env.settle()
+        channel = guild.create_text_channel("general")
+        member = guild.add_member(env.create_user("Ada"))
+        await env.settle()
+        return SimcordMemberChannel(guild, member, channel)
+
+    return make
+
+
+@pytest.fixture
+async def simcord_member_channel(
+    simcord_env: Env,
+    make_simcord_member_channel: MakeSimcordMemberChannel,
+) -> SimcordMemberChannel:
+    """Create one guild text channel and human member in the default Simcord env."""
+    return await make_simcord_member_channel(simcord_env)
+
+
+@pytest.fixture
+def start_words_for_channel() -> StartWordsForChannel:
+    """Return a reader for persisted Markov start words in one Discord channel."""
+
+    async def read(db: Database, channel_id: int) -> list[str]:
+        async with db._connection.execute(
+            "SELECT word FROM markov_start_words WHERE channel_id = ? ORDER BY word",
+            (channel_id,),
+        ) as cursor:
+            return [str(row[0]) for row in await cursor.fetchall()]
+
+    return read

tests/integration/discord/test_bot_lifecycle.py

@@ -0,0 +1,251 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Simcord integration tests for Crabstero bot lifecycle behavior."""
+
+from typing import TYPE_CHECKING, Any, cast
+
+import discord
+import pytest
+from discord import app_commands
+from simcord import run
+
+from crabstero import metrics
+from crabstero.bot import Crabstero, TrackedModal, TrackedView
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+    from simcord import Env
+
+    from tests.integration.discord.conftest import (
+        MakeSimcordMemberChannel,
+        SimcordMemberChannel,
+    )
+
+
+def _counter_value(counter: Any, **labels: str) -> float:
+    """Return the current value for a labelled Prometheus counter."""
+    return float(counter.labels(**labels)._value.get())
+
+
+class TestSetupHook:
+    """Bot startup wires Discord cogs and slash commands under Simcord."""
+
+    def test_db_before_setup_raises(self, tmp_path: Path) -> None:
+        """The database property is unavailable before setup_hook runs."""
+        bot = Crabstero(str(tmp_path / "not-started.db"))
+
+        with pytest.raises(RuntimeError, match="Database is not initialized"):
+            _ = bot.db
+
+    async def test_loads_cogs_and_syncs_commands(
+        self,
+        simcord_env: Env,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """setup_hook loads expected cogs and syncs app commands."""
+        assert set(crabstero_bot.cogs) == {
+            "InteractionCog",
+            "MessageCog",
+            "ServerEventsCog",
+        }
+
+        commands = simcord_env.backend.commands[None]
+        assert {name for name, _ in commands} == {"forgetme", "pingme"}
+
+        application_id = simcord_env.backend.application_id
+        http_routes = [f"{method} {path}" for method, path, _ in simcord_env.http_log]
+        assert f"GET /applications/{application_id}/commands" in http_routes
+        assert f"PUT /applications/{application_id}/commands" in http_routes
+
+    async def test_metrics_server_lifecycle_starts_and_stops(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """A configured metrics server is started and stopped with the bot."""
+        bot = Crabstero(
+            str(tmp_path / "metrics.db"),
+            metrics_address=metrics.TcpMetricsAddress("127.0.0.1", 0),
+        )
+        try:
+            async with run(bot):
+                assert bot._metrics_server is not None
+                assert bot._metrics_server.port > 0
+        finally:
+            bot.ws = None  # type: ignore[assignment]
+            await bot.close()
+
+
+class TestMetrics:
+    """Bot-level metrics are incremented by lifecycle error paths."""
+
+    def test_dispatch_increments_discord_event_metric(
+        self,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """Dispatch increments the labelled Discord event counter."""
+        event = "codex_lifecycle_metric"
+        before = _counter_value(metrics.DISCORD_EVENTS, event=event)
+
+        crabstero_bot.dispatch(event)
+
+        assert _counter_value(metrics.DISCORD_EVENTS, event=event) == before + 1
+
+    async def test_on_error_increments_event_error_metric(
+        self,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """Unhandled event listener failures are counted by event name."""
+        source = "on_message"
+        before = _counter_value(metrics.ERRORS, source=source)
+
+        await crabstero_bot.on_error(source)
+
+        assert _counter_value(metrics.ERRORS, source=source) == before + 1
+
+    async def test_tracked_view_and_modal_errors_increment_metrics(self) -> None:
+        """Tracked UI error handlers increment their error counters."""
+        view_before = _counter_value(metrics.ERRORS, source="view")
+        modal_before = _counter_value(metrics.ERRORS, source="modal")
+        interaction = cast("discord.Interaction", object())
+        button = cast("discord.ui.Item[TrackedView]", discord.ui.Button(label="Run"))
+
+        await TrackedView().on_error(interaction, RuntimeError("view failed"), button)
+        await TrackedModal(title="Tracked").on_error(
+            interaction,
+            RuntimeError("modal failed"),
+        )
+
+        assert _counter_value(metrics.ERRORS, source="view") == view_before + 1
+        assert _counter_value(metrics.ERRORS, source="modal") == modal_before + 1
+
+
+class TestCommandErrors:
+    """Unhandled app command errors produce an ephemeral fallback response."""
+
+    async def test_app_command_error_sends_ephemeral_fallback(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        monkeypatch: pytest.MonkeyPatch,
+    ) -> None:
+        """A failing slash command is captured and answered by tree.on_error."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+
+        async def raise_on_set_flag(
+            _entity_type: str,
+            _entity_id: str,
+            _flag_name: str,
+        ) -> None:
+            raise RuntimeError("database unavailable")
+
+        monkeypatch.setattr(crabstero_bot.db, "set_flag", raise_on_set_flag)
+        errors_before = _counter_value(metrics.ERRORS, source="command")
+
+        result = await member.slash(channel, "pingme")
+
+        assert result.response is not None
+        assert result.response.ephemeral is True
+        assert result.response.content == (
+            "I encountered an error while processing this command."
+            " Please try again later."
+        )
+        assert _counter_value(metrics.ERRORS, source="command") == errors_before + 1
+
+    async def test_app_command_error_mentions_developer_when_metrics_are_enabled(
+        self,
+        tmp_path: Path,
+        monkeypatch: pytest.MonkeyPatch,
+        make_simcord_member_channel: MakeSimcordMemberChannel,
+    ) -> None:
+        """Configured metrics switch command errors to the notified-developer copy."""
+        bot = Crabstero(
+            str(tmp_path / "metrics-command-errors.db"),
+            metrics_address=metrics.TcpMetricsAddress("127.0.0.1", 0),
+        )
+        try:
+            async with run(bot) as env:
+                context = await make_simcord_member_channel(env)
+                member = context.member
+                channel = context.channel
+
+                async def raise_on_set_flag(
+                    _entity_type: str,
+                    _entity_id: str,
+                    _flag_name: str,
+                ) -> None:
+                    raise RuntimeError("database unavailable")
+
+                monkeypatch.setattr(bot.db, "set_flag", raise_on_set_flag)
+                errors_before = _counter_value(metrics.ERRORS, source="command")
+
+                result = await member.slash(channel, "pingme")
+
+                assert result.response is not None
+                assert result.response.ephemeral is True
+                assert result.response.content == (
+                    "I encountered an error while processing this command."
+                    " The developer has been notified,"
+                    " please try again later."
+                )
+                assert (
+                    _counter_value(metrics.ERRORS, source="command")
+                    == errors_before + 1
+                )
+        finally:
+            bot.ws = None  # type: ignore[assignment]
+            await bot.close()
+
+    async def test_app_command_error_after_defer_sends_ephemeral_followup(
+        self,
+        tmp_path: Path,
+        make_simcord_member_channel: MakeSimcordMemberChannel,
+    ) -> None:
+        """A command that has already acknowledged uses a followup fallback."""
+        bot = Crabstero(str(tmp_path / "deferred-command-errors.db"))
+
+        @app_commands.command(
+            name="deferboom",
+            description="Fail after acknowledging the interaction.",
+        )
+        async def deferboom(interaction: discord.Interaction) -> None:
+            await interaction.response.defer(ephemeral=True)
+            raise RuntimeError("deferred command failed")
+
+        bot.tree.add_command(deferboom)
+        try:
+            async with run(bot) as env:
+                context = await make_simcord_member_channel(env)
+                errors_before = _counter_value(metrics.ERRORS, source="command")
+
+                result = await context.member.slash(context.channel, "deferboom")
+
+                assert result.deferred is True
+                assert result.response is None
+                assert len(result.followups) == 1
+                followup = result.followups[0]
+                assert followup.ephemeral is True
+                assert followup.content == (
+                    "I encountered an error while processing this command."
+                    " Please try again later."
+                )
+                assert (
+                    _counter_value(metrics.ERRORS, source="command")
+                    == errors_before + 1
+                )
+        finally:
+            bot.ws = None  # type: ignore[assignment]
+            await bot.close()

tests/integration/discord/test_interactions.py

@@ -0,0 +1,276 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Simcord integration tests for Crabstero slash commands."""
+
+from collections.abc import Awaitable, Callable
+from typing import TYPE_CHECKING
+
+import pytest
+
+from crabstero.database import ChannelImage, StartWord, Transition
+from crabstero.flags import Flag
+
+if TYPE_CHECKING:
+    from simcord import Env
+
+    from crabstero.bot import Crabstero
+    from crabstero.database import Database
+    from tests.integration.discord.conftest import SimcordMemberChannel
+
+type SeedForgetmeData = Callable[["Database", int], Awaitable[None]]
+type ForgetmeRowsForUser = Callable[["Database", int], Awaitable[tuple[int, int, int]]]
+
+
+@pytest.fixture
+def seed_forgetme_data() -> SeedForgetmeData:
+    """Return a seeder for user-owned and unrelated /forgetme database rows."""
+
+    async def seed(db: Database, user_id: int) -> None:
+        await db.add_markov_data(
+            [
+                StartWord(10, user_id, "delete"),
+                StartWord(10, 999, "keep"),
+            ],
+            [
+                Transition(10, user_id, "delete", "me."),
+                Transition(10, 999, "keep", "me."),
+            ],
+        )
+        await db.add_images(
+            [
+                ChannelImage(10, user_id, "https://example.com/delete.png"),
+                ChannelImage(10, 999, "https://example.com/keep.png"),
+            ],
+        )
+
+    return seed
+
+
+@pytest.fixture
+def forgetme_rows_for_user() -> ForgetmeRowsForUser:
+    """Return a reader for Markov/image row counts owned by one user."""
+
+    async def read(db: Database, user_id: int) -> tuple[int, int, int]:
+        async with db._connection.execute(
+            "SELECT COUNT(*) FROM markov_start_words WHERE user_id = ?",
+            (user_id,),
+        ) as cursor:
+            row = await cursor.fetchone()
+            assert row is not None
+            start_words = row[0]
+        async with db._connection.execute(
+            "SELECT COUNT(*) FROM markov_transitions WHERE user_id = ?",
+            (user_id,),
+        ) as cursor:
+            row = await cursor.fetchone()
+            assert row is not None
+            transitions = row[0]
+        async with db._connection.execute(
+            "SELECT COUNT(*) FROM channel_images WHERE user_id = ?",
+            (user_id,),
+        ) as cursor:
+            row = await cursor.fetchone()
+            assert row is not None
+            images = row[0]
+        return int(start_words), int(transitions), int(images)
+
+    return read
+
+
+class TestPingMe:
+    """The /pingme command toggles persisted user opt-in state."""
+
+    async def test_first_call_opts_in(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """The first /pingme call sets allowPings and responds ephemerally."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+
+        result = await member.slash(channel, "pingme")
+
+        assert result.response is not None
+        assert result.response.ephemeral is True
+        assert "I will now ping you" in result.response.content
+        assert await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.ALLOW_PINGS,
+        )
+
+    async def test_second_call_opts_out(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """The second /pingme call clears allowPings and responds ephemerally."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await member.slash(channel, "pingme")
+
+        result = await member.slash(channel, "pingme")
+
+        assert result.response is not None
+        assert result.response.ephemeral is True
+        assert "I will no longer ping you" in result.response.content
+        assert not await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.ALLOW_PINGS,
+        )
+
+
+class TestForgetMe:
+    """The /forgetme command confirms, cancels, and times out hermetically."""
+
+    async def test_initial_response_has_confirmation_buttons(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+    ) -> None:
+        """The first /forgetme response is ephemeral and asks for confirmation."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+
+        result = await member.slash(channel, "forgetme")
+
+        assert result.response is not None
+        assert result.response.ephemeral is True
+        assert "Would you like to proceed?" in result.response.content
+        labels = [
+            component["label"]
+            for row in result.response.components
+            for component in row["components"]
+        ]
+        assert labels == ["Confirm", "Cancel"]
+
+    async def test_confirm_deletes_user_data_and_sets_no_ingest(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        seed_forgetme_data: SeedForgetmeData,
+        forgetme_rows_for_user: ForgetmeRowsForUser,
+    ) -> None:
+        """Confirming /forgetme deletes user data and persists noIngest."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await seed_forgetme_data(crabstero_bot.db, member.id)
+        await crabstero_bot.db.set_flag("user", str(member.id), Flag.ALLOW_PINGS)
+        await crabstero_bot.db.set_flag("user", str(member.id), Flag.NO_REPLY)
+        prompt = (await member.slash(channel, "forgetme")).response
+        assert prompt is not None
+
+        result = await member.click(prompt, label="Confirm")
+
+        assert result.response is not None
+        assert result.response.ephemeral is True
+        assert "I have deleted your data" in result.response.content
+        assert result.response.components == []
+        assert await forgetme_rows_for_user(crabstero_bot.db, member.id) == (0, 0, 0)
+        assert await forgetme_rows_for_user(crabstero_bot.db, 999) == (1, 1, 1)
+        assert await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.NO_INGEST,
+        )
+        assert not await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.ALLOW_PINGS,
+        )
+        assert not await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.NO_REPLY,
+        )
+
+    async def test_cancel_leaves_user_data_and_flags(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        seed_forgetme_data: SeedForgetmeData,
+        forgetme_rows_for_user: ForgetmeRowsForUser,
+    ) -> None:
+        """Cancelling /forgetme leaves data and user flags unchanged."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await seed_forgetme_data(crabstero_bot.db, member.id)
+        await crabstero_bot.db.set_flag("user", str(member.id), Flag.ALLOW_PINGS)
+        await crabstero_bot.db.set_flag("user", str(member.id), Flag.NO_REPLY)
+        prompt = (await member.slash(channel, "forgetme")).response
+        assert prompt is not None
+
+        result = await member.click(prompt, label="Cancel")
+
+        assert result.response is not None
+        assert result.response.ephemeral is True
+        assert result.response.content == (
+            "Action cancelled. I have not modified your data."
+        )
+        assert result.response.components == []
+        assert await forgetme_rows_for_user(crabstero_bot.db, member.id) == (1, 1, 1)
+        assert await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.ALLOW_PINGS,
+        )
+        assert await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.NO_REPLY,
+        )
+        assert not await crabstero_bot.db.is_flag_set(
+            "user",
+            str(member.id),
+            Flag.NO_INGEST,
+        )
+
+    async def test_already_forgotten_user_gets_terminal_response(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """A noIngest user does not get another confirmation view."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await crabstero_bot.db.set_flag("user", str(member.id), Flag.NO_INGEST)
+
+        result = await member.slash(channel, "forgetme")
+
+        assert result.response is not None
+        assert result.response.ephemeral is True
+        assert result.response.content == (
+            "I have already removed your data and I am not using your messages."
+        )
+        assert result.response.components == []
+
+    async def test_confirmation_timeout_removes_view(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+    ) -> None:
+        """The /forgetme view timeout edits the original response without sleeping."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        prompt = (await member.slash(channel, "forgetme")).response
+        assert prompt is not None
+
+        await simcord_env.advance_time(181)
+
+        assert prompt.content == (
+            "This timed out. Run `/forgetme` again if you still want to."
+        )
+        assert prompt.components == []

tests/integration/discord/test_messages.py

@@ -0,0 +1,470 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Simcord integration tests for Discord message events."""
+
+from collections.abc import Awaitable, Callable
+from typing import TYPE_CHECKING
+
+import discord
+import pytest
+from simcord import run
+
+from crabstero.bot import Crabstero
+from crabstero.database import ChannelImage, StartWord, Transition
+from crabstero.flags import EntityType, Flag
+from crabstero.messages import ingest_message, reply_to_message
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+    from simcord import Env
+
+    from crabstero.database import Database
+    from tests.integration.discord.conftest import (
+        MakeSimcordMemberChannel,
+        SimcordMemberChannel,
+        StartWordsForChannel,
+    )
+
+type SeedReply = Callable[["Database", int], Awaitable[None]]
+
+
+@pytest.fixture
+def seed_reply() -> SeedReply:
+    """Return a seeder for deterministic generated replies in one channel."""
+
+    async def seed(db: Database, channel_id: int) -> None:
+        await db.add_markov_data(
+            [StartWord(channel_id, 123, "Generated")],
+            [Transition(channel_id, 123, "Generated", "reply.")],
+        )
+
+    return seed
+
+
+class TestMessageIngestion:
+    """Normal Discord message flow populates the real database."""
+
+    async def test_normal_guild_user_message_is_ingested(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """A default guild text message adds Markov data."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+
+        await member.send(channel, "Alpha beta.")
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == ["Alpha"]
+        assert (
+            await crabstero_bot.db.get_random_next_word(channel.id, "Alpha") == "beta."
+        )
+
+    async def test_bot_messages_are_ignored(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """A bot-authored gateway message is not ingested."""
+        channel = simcord_member_channel.channel
+
+        simcord_env.backend.create_message(
+            channel.id,
+            simcord_env.backend.bot_user.id,
+            "Ignore bot.",
+        )
+        await simcord_env.settle()
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []
+
+    async def test_dm_messages_are_ignored(
+        self,
+        simcord_env: Env,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """DM messages are outside the guild channel types Crabstero handles."""
+        user = simcord_env.create_user("Ada")
+
+        await user.send_dm("Direct message.")
+
+        assert (
+            await start_words_for_channel(
+                crabstero_bot.db,
+                user.dm_channel.id,
+            )
+            == []
+        )
+
+    async def test_thread_messages_do_not_create_separate_chain(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """Messages inside threads are not ingested under the thread channel id."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        simcord_env.backend.create_thread(channel.id, "thread", member.id)
+        await simcord_env.settle()
+        thread = channel.threads[0]
+
+        await member.send(thread, "Thread only.")
+
+        assert await start_words_for_channel(crabstero_bot.db, thread.id) == []
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []
+
+    async def test_embed_message_text_and_image_are_ingested(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """Embed titles, descriptions, and image URLs are ingested."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+
+        simcord_env.backend.create_message(
+            channel.id,
+            member.id,
+            embeds=[
+                {
+                    "title": "Title words.",
+                    "description": "Description words.",
+                    "image": {"url": "https://example.com/embed.png"},
+                },
+            ],
+        )
+        await simcord_env.settle()
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == [
+            "Description",
+            "Title",
+        ]
+        assert (
+            await crabstero_bot.db.get_random_image(channel.id)
+            == "https://example.com/embed.png"
+        )
+
+    async def test_empty_messages_are_not_ingested(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """A message with no content or embeds is ignored."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+
+        await member.send(channel)
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []
+
+    async def test_ingest_only_mode_ingests_without_replying(
+        self,
+        tmp_path: Path,
+        make_simcord_member_channel: MakeSimcordMemberChannel,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """An ingest-only bot still ingests eligible messages and never replies."""
+        bot = Crabstero(str(tmp_path / "ingest-only.db"), ingest_only=True)
+        try:
+            async with run(bot) as env:
+                context = await make_simcord_member_channel(env)
+                member = context.member
+                channel = context.channel
+
+                await member.send(channel, "Ingest only.")
+
+                assert await start_words_for_channel(bot.db, channel.id) == ["Ingest"]
+                assert [message.content for message in channel.history()] == [
+                    "Ingest only.",
+                ]
+        finally:
+            bot.ws = None  # type: ignore[assignment]
+            await bot.close()
+
+
+class TestReplies:
+    """Mentions produce replies through the real Discord message path."""
+
+    async def test_mentioning_bot_sends_seeded_reply(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        seed_reply: SeedReply,
+    ) -> None:
+        """A mention causes a deterministic Markov reply to be posted."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await seed_reply(crabstero_bot.db, channel.id)
+
+        await member.send(channel, f"<@{simcord_env.backend.bot_user.id}> please reply")
+
+        history = channel.history()
+        assert [message.content for message in history] == [
+            f"<@{simcord_env.backend.bot_user.id}> please reply",
+            "Generated reply.",
+        ]
+        assert history[-1].reference is not None
+        assert history[-1].author == simcord_env.bot.user
+
+    async def test_mention_reply_can_include_embed_and_image(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        monkeypatch: pytest.MonkeyPatch,
+        seed_reply: SeedReply,
+    ) -> None:
+        """The optional reply embed path uses generated text and stored images."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await seed_reply(crabstero_bot.db, channel.id)
+        await crabstero_bot.db.add_images(
+            [ChannelImage(channel.id, 123, "https://example.com/reply.png")],
+        )
+        monkeypatch.setattr("crabstero.messages.secrets.randbelow", lambda _upper: 95)
+
+        await member.send(channel, f"<@{simcord_env.backend.bot_user.id}> please reply")
+
+        reply = channel.history()[-1]
+        assert reply.content == "Generated reply."
+        assert len(reply.embeds) == 1
+        assert reply.embeds[0].title == "Generated reply."
+        assert reply.embeds[0].description == "Generated reply."
+        assert reply.embeds[0].image.url == "https://example.com/reply.png"
+
+    async def test_mention_in_thread_uses_parent_channel_chain(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        seed_reply: SeedReply,
+    ) -> None:
+        """A thread mention generates from the parent channel's Markov chain."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await seed_reply(crabstero_bot.db, channel.id)
+        simcord_env.backend.create_thread(channel.id, "thread", member.id)
+        await simcord_env.settle()
+        thread = channel.threads[0]
+
+        await member.send(thread, f"<@{simcord_env.backend.bot_user.id}> thread reply")
+
+        assert [message.content for message in thread.history()] == [
+            f"<@{simcord_env.backend.bot_user.id}> thread reply",
+            "Generated reply.",
+        ]
+
+    async def test_allow_pings_flag_allows_generated_user_mentions(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """Generated mentions are allowed for users who opted in."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        target = simcord_env.create_user("Mentioned")
+        await crabstero_bot.db.add_markov_data(
+            [StartWord(channel.id, 123, "Hello")],
+            [Transition(channel.id, 123, "Hello", f"{target.mention}.")],
+        )
+        await crabstero_bot.db.set_flag(
+            EntityType.USER,
+            str(target.id),
+            Flag.ALLOW_PINGS,
+        )
+
+        await member.send(channel, f"<@{simcord_env.backend.bot_user.id}> please reply")
+
+        assert channel.history()[-1].content == f"Hello {target.mention}."
+
+    async def test_no_reply_flag_suppresses_reply(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        seed_reply: SeedReply,
+    ) -> None:
+        """The noReply flag prevents a mention response."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await seed_reply(crabstero_bot.db, channel.id)
+        await crabstero_bot.db.set_flag(
+            EntityType.CHANNEL,
+            str(channel.id),
+            Flag.NO_REPLY,
+        )
+
+        await member.send(channel, f"<@{simcord_env.backend.bot_user.id}> please reply")
+
+        assert [message.content for message in channel.history()] == [
+            f"<@{simcord_env.backend.bot_user.id}> please reply",
+        ]
+
+    async def test_missing_send_permission_suppresses_reply(
+        self,
+        simcord_env: Env,
+        crabstero_bot: Crabstero,
+        seed_reply: SeedReply,
+    ) -> None:
+        """A bot without send_messages permission does not reply."""
+        guild = simcord_env.create_guild()
+        bot_role = guild.roles[simcord_env.backend.bot_user.name]
+        channel = guild.create_text_channel(
+            "readonly",
+            overwrites={
+                bot_role: discord.PermissionOverwrite(send_messages=False),
+            },
+        )
+        member = guild.add_member(simcord_env.create_user("Ada"))
+        await simcord_env.settle()
+        await seed_reply(crabstero_bot.db, channel.id)
+
+        await member.send(channel, f"<@{simcord_env.backend.bot_user.id}> please reply")
+
+        assert [message.content for message in channel.history()] == [
+            f"<@{simcord_env.backend.bot_user.id}> please reply",
+        ]
+
+    async def test_direct_dm_reply_is_ignored(
+        self,
+        simcord_env: Env,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """The reply helper ignores messages outside guilds."""
+        user = simcord_env.create_user("Ada")
+        message = await user.send_dm(f"<@{simcord_env.backend.bot_user.id}> hi")
+
+        await reply_to_message(crabstero_bot.db, message)
+
+        assert [message.content for message in user.dm_channel.history()] == [
+            f"<@{simcord_env.backend.bot_user.id}> hi",
+        ]
+
+
+class TestDeletes:
+    """Raw delete events reverse recent message ingestion."""
+
+    async def test_delete_reverses_recent_ingest(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """Deleting a cached message removes its Markov rows."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        message = await member.send(channel, "Delete me.")
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == [
+            "Delete",
+        ]
+
+        await member.delete(message)
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []
+
+    async def test_bulk_delete_reverses_recent_ingests(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """Bulk-deleting cached messages removes their Markov rows."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        first = await member.send(channel, "Bulk one.")
+        second = await member.send(channel, "Bulk two.")
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == [
+            "Bulk",
+            "Bulk",
+        ]
+
+        simcord_env.backend.bulk_delete_messages(channel.id, [first.id, second.id])
+        await simcord_env.settle()
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []
+
+
+class TestFlagSuppression:
+    """Message behavior respects persisted noIngest and noReply flags."""
+
+    async def test_no_ingest_user_flag_suppresses_ingestion(
+        self,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """The noIngest flag prevents storing a user's message."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await crabstero_bot.db.set_flag(
+            EntityType.USER,
+            str(member.id),
+            Flag.NO_INGEST,
+        )
+
+        await member.send(channel, "Do not learn.")
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []
+
+    async def test_direct_dm_ingest_is_ignored(
+        self,
+        simcord_env: Env,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """The ingest helper ignores messages outside guilds."""
+        user = simcord_env.create_user("Ada")
+        message = await user.send_dm("Direct helper call.")
+
+        await ingest_message(crabstero_bot.db, message)
+
+        assert (
+            await start_words_for_channel(
+                crabstero_bot.db,
+                user.dm_channel.id,
+            )
+            == []
+        )
+
+    async def test_direct_bot_mention_ingest_is_ignored(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """The ingest helper ignores messages that mention the bot."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        message = await member.send(
+            channel,
+            f"<@{simcord_env.backend.bot_user.id}> do not learn",
+        )
+
+        await ingest_message(crabstero_bot.db, message)
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []

tests/integration/discord/test_server_events.py

@@ -0,0 +1,277 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Simcord integration tests for server event ingestion triggers."""
+
+from typing import TYPE_CHECKING
+
+import discord
+import pytest
+from simcord.backend.models import Overwrite
+from simcord.enums import OverwriteType
+
+from crabstero.listeners.server_events import ServerEventsCog
+from crabstero.tasks.ingestion import ingest_channel
+
+if TYPE_CHECKING:
+    from simcord import Env
+
+    from crabstero.bot import Crabstero
+    from tests.integration.discord.conftest import (
+        SimcordMemberChannel,
+        SimcordTextChannel,
+        StartWordsForChannel,
+    )
+
+
+@pytest.fixture
+def server_events_cog(crabstero_bot: Crabstero) -> ServerEventsCog:
+    """Return the loaded server-events cog from the Simcord-backed bot."""
+    cog = crabstero_bot.get_cog("ServerEventsCog")
+    assert isinstance(cog, ServerEventsCog)
+    return cog
+
+
+class TestGuildEvents:
+    """Guild availability and joins queue local channel history ingestion."""
+
+    async def test_guild_available_queues_text_and_voice_channels(
+        self,
+        simcord_env: Env,
+        server_events_cog: ServerEventsCog,
+    ) -> None:
+        """Available guilds enqueue all textable channels."""
+        guild = simcord_env.create_guild()
+        await simcord_env.settle()
+        text = guild.create_text_channel("general")
+        voice = guild.create_voice_channel("voice")
+        await simcord_env.settle()
+        cached_guild = simcord_env.bot.get_guild(guild.id)
+        assert cached_guild is not None
+
+        await server_events_cog.on_guild_available(cached_guild)
+        await simcord_env.settle()
+
+        assert await server_events_cog.bot.db.is_channel_ingested(text.id)
+        assert await server_events_cog.bot.db.is_channel_ingested(voice.id)
+
+    async def test_guild_join_queues_ingestion_and_attempts_owner_notification(
+        self,
+        simcord_env: Env,
+        simcord_text_channel: SimcordTextChannel,
+        server_events_cog: ServerEventsCog,
+    ) -> None:
+        """Joining a guild enqueues ingestion and uses the fake owner DM path."""
+        guild = simcord_text_channel.guild
+        channel = simcord_text_channel.channel
+        cached_guild = simcord_env.bot.get_guild(guild.id)
+        assert cached_guild is not None
+
+        await server_events_cog.on_guild_join(cached_guild)
+        await simcord_env.settle()
+
+        assert await server_events_cog.bot.db.is_channel_ingested(channel.id)
+        http_routes = [f"{method} {path}" for method, path, _ in simcord_env.http_log]
+        assert "GET /oauth2/applications/@me" in http_routes
+        assert "POST /users/@me/channels" in http_routes
+        assert any(route.endswith("/messages") for route in http_routes)
+
+
+class TestPermissionUpdateEvents:
+    """Permission-changing events trigger ingestion only when relevant."""
+
+    async def test_role_update_queues_only_when_permissions_change_for_bot_role(
+        self,
+        simcord_env: Env,
+        simcord_text_channel: SimcordTextChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """Role updates require changed permissions and bot membership."""
+        guild = simcord_text_channel.guild
+        channel = simcord_text_channel.channel
+        role = guild.create_role("reader", permissions=discord.Permissions.none())
+        await simcord_env.settle()
+
+        simcord_env.backend.edit_role(
+            guild.id,
+            role.id,
+            {"permissions": discord.Permissions(view_channel=True).value},
+        )
+        await simcord_env.settle()
+        assert not await crabstero_bot.db.is_channel_ingested(channel.id)
+
+        bot_role = guild.roles[simcord_env.backend.bot_user.name]
+        simcord_env.backend.edit_role(
+            guild.id,
+            bot_role.id,
+            {
+                "permissions": discord.Permissions(
+                    view_channel=True,
+                    read_message_history=True,
+                ).value,
+            },
+        )
+        await simcord_env.settle()
+
+        assert await crabstero_bot.db.is_channel_ingested(channel.id)
+
+    async def test_role_update_same_permissions_does_not_queue(
+        self,
+        simcord_env: Env,
+        simcord_text_channel: SimcordTextChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """A role update without permission changes is ignored."""
+        guild = simcord_text_channel.guild
+        channel = simcord_text_channel.channel
+        role = guild.create_role(
+            "reader",
+            permissions=discord.Permissions(read_message_history=True),
+        )
+        simcord_env.backend.add_member_role(
+            guild.id,
+            simcord_env.backend.bot_user.id,
+            role.id,
+        )
+        await simcord_env.settle()
+
+        simcord_env.backend.edit_role(
+            guild.id,
+            role.id,
+            {"permissions": discord.Permissions(read_message_history=True).value},
+        )
+        await simcord_env.settle()
+
+        assert not await crabstero_bot.db.is_channel_ingested(channel.id)
+
+    async def test_channel_update_queues_only_when_overwrites_change(
+        self,
+        simcord_env: Env,
+        simcord_text_channel: SimcordTextChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """Channel updates without overwrite changes do not enqueue ingestion."""
+        guild = simcord_text_channel.guild
+        channel = simcord_text_channel.channel
+
+        simcord_env.backend.edit_channel(channel.id, {"topic": "no permission change"})
+        await simcord_env.settle()
+        assert not await crabstero_bot.db.is_channel_ingested(channel.id)
+
+        simcord_env.backend.set_overwrite(
+            channel.id,
+            Overwrite(
+                target_id=guild.default_role.id,
+                type=OverwriteType.ROLE,
+                allow=discord.Permissions(read_message_history=True).value,
+                deny=0,
+            ),
+        )
+        await simcord_env.settle()
+
+        assert await crabstero_bot.db.is_channel_ingested(channel.id)
+
+
+class TestIngestionTasks:
+    """Server-triggered ingestion task behavior stays local and deterministic."""
+
+    async def test_duplicate_channel_queue_requests_share_one_task(
+        self,
+        simcord_env: Env,
+        simcord_text_channel: SimcordTextChannel,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """Queuing the same channel twice before the loop runs creates one task."""
+        channel = simcord_text_channel.channel
+        cached_channel = simcord_env.bot.get_channel(channel.id)
+        assert isinstance(cached_channel, discord.TextChannel)
+
+        crabstero_bot.queue_channel_for_ingestion(cached_channel)
+        crabstero_bot.queue_channel_for_ingestion(cached_channel)
+
+        assert list(crabstero_bot._ingestion_tasks) == [channel.id]
+        await simcord_env.settle()
+
+    async def test_channel_history_ingestion_requires_read_history_permission(
+        self,
+        simcord_env: Env,
+        crabstero_bot: Crabstero,
+    ) -> None:
+        """A channel missing read history permission is skipped."""
+        guild = simcord_env.create_guild()
+        channel = guild.create_text_channel(
+            "hidden-history",
+            overwrites={
+                guild.default_role: discord.PermissionOverwrite(
+                    read_message_history=False,
+                ),
+            },
+        )
+        await simcord_env.settle()
+        cached_channel = simcord_env.bot.get_channel(channel.id)
+        assert isinstance(cached_channel, discord.TextChannel)
+
+        await ingest_channel(cached_channel, crabstero_bot.db)
+
+        assert not await crabstero_bot.db.is_channel_ingested(channel.id)
+
+    async def test_channel_history_ingestion_reads_existing_messages(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """Bulk channel ingestion reads historical messages through Discord."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        cached_channel = simcord_env.bot.get_channel(channel.id)
+        assert isinstance(cached_channel, discord.TextChannel)
+        simcord_env.backend.create_message(
+            channel.id,
+            member.id,
+            "Historical message.",
+            broadcast=False,
+        )
+
+        await ingest_channel(cached_channel, crabstero_bot.db)
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == [
+            "Historical",
+        ]
+        assert await crabstero_bot.db.is_channel_ingested(channel.id)
+
+    async def test_already_ingested_channel_is_skipped(
+        self,
+        simcord_env: Env,
+        simcord_member_channel: SimcordMemberChannel,
+        crabstero_bot: Crabstero,
+        start_words_for_channel: StartWordsForChannel,
+    ) -> None:
+        """A channel marked ingested is not read again."""
+        member = simcord_member_channel.member
+        channel = simcord_member_channel.channel
+        await crabstero_bot.db.mark_channel_ingested(channel.id)
+        cached_channel = simcord_env.bot.get_channel(channel.id)
+        assert isinstance(cached_channel, discord.TextChannel)
+        simcord_env.backend.create_message(
+            channel.id,
+            member.id,
+            "Historical message.",
+            broadcast=False,
+        )
+
+        await ingest_channel(cached_channel, crabstero_bot.db)
+
+        assert await start_words_for_channel(crabstero_bot.db, channel.id) == []

tests/integration/metrics/__init__.py

@@ -0,0 +1,15 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Metrics integration tests for Crabstero."""

tests/integration/metrics/test_server.py

@@ -0,0 +1,196 @@
+# Copyright 2026 Logan Fick
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Integration tests for the Prometheus metrics HTTP server."""
+
+import errno
+import os
+import socket
+from dataclasses import dataclass
+from http import HTTPStatus
+from typing import TYPE_CHECKING, Literal, cast
+
+import aiohttp
+import pytest
+
+from crabstero.metrics import MetricsServer, TcpMetricsAddress, UnixMetricsAddress
+
+if TYPE_CHECKING:
+    from collections.abc import AsyncGenerator
+    from pathlib import Path
+
+
+type MetricsTransport = Literal["tcp", "unix-socket"]
+
+requires_unix_socket = pytest.mark.skipif(
+    os.name != "posix" or not hasattr(socket, "AF_UNIX"),
+    reason="Unix-socket metrics transports require Unix-domain socket support",
+)
+
+
+@dataclass(frozen=True, slots=True)
+class MetricsEndpoint:
+    """Client details for one running metrics transport."""
+
+    base_url: str
+    unix_socket_path: str | None = None
+
+    def client_session(self) -> aiohttp.ClientSession:
+        """Create an aiohttp client session for this metrics transport."""
+        connector = (
+            aiohttp.UnixConnector(path=self.unix_socket_path)
+            if self.unix_socket_path is not None
+            else None
+        )
+        return aiohttp.ClientSession(connector=connector)
+
+
+@pytest.fixture(
+    params=[
+        pytest.param("tcp", id="tcp"),
+        pytest.param("unix-socket", marks=requires_unix_socket, id="unix-socket"),
+    ],
+)
+async def metrics_endpoint(
+    request: pytest.FixtureRequest,
+    tmp_path: Path,
+) -> AsyncGenerator[MetricsEndpoint]:
+    """Start a MetricsServer on each supported transport."""
+    transport = cast("MetricsTransport", request.param)
+    match transport:
+        case "tcp":
+            server = MetricsServer(TcpMetricsAddress("127.0.0.1", 0))
+            await server.start()
+            endpoint = MetricsEndpoint(f"http://127.0.0.1:{server.port}")
+        case "unix-socket":
+            socket_path = tmp_path / "metrics.sock"
+            server = MetricsServer(UnixMetricsAddress(str(socket_path)))
+            await server.start()
+            endpoint = MetricsEndpoint(
+                "http://crabstero",
+                unix_socket_path=str(socket_path),
+            )
+
+    try:
+        yield endpoint
+    finally:
+        await server.stop()
+
+
+class TestMetricsServer:
+    """HTTP server serves Prometheus metrics on /metrics."""
+
+    @requires_unix_socket
+    def test_unix_socket_server_has_no_tcp_port(self, tmp_path: Path) -> None:
+        """Unix-socket metrics servers do not expose a TCP port."""
+        server = MetricsServer(UnixMetricsAddress(str(tmp_path / "metrics.sock")))
+
+        with pytest.raises(RuntimeError, match="does not have a TCP port"):
+            _ = server.port
+
+    async def test_serves_metrics_endpoint(
+        self,
+        metrics_endpoint: MetricsEndpoint,
+    ) -> None:
+        """GET /metrics returns 200 with metric output containing our metrics."""
+        async with (
+            metrics_endpoint.client_session() as session,
+            session.get(f"{metrics_endpoint.base_url}/metrics") as resp,
+        ):
+            assert resp.status == HTTPStatus.OK
+            body = await resp.text()
+            assert "crabstero_build_info" in body
+
+    async def test_non_metrics_path_returns_404(
+        self,
+        metrics_endpoint: MetricsEndpoint,
+    ) -> None:
+        """GET on an unknown path returns 404."""
+        async with (
+            metrics_endpoint.client_session() as session,
+            session.get(f"{metrics_endpoint.base_url}/notfound") as resp,
+        ):
+            assert resp.status == HTTPStatus.NOT_FOUND
+
+    @requires_unix_socket
+    async def test_unix_socket_mode_is_applied(self, tmp_path: Path) -> None:
+        """Configured Unix socket mode is applied after startup."""
+        socket_path = tmp_path / "metrics.sock"
+        server = MetricsServer(UnixMetricsAddress(str(socket_path), mode=0o666))
+        await server.start()
+        try:
+            assert socket_path.stat().st_mode & 0o777 == 0o666
+        finally:
+            await server.stop()
+
+    @requires_unix_socket
+    async def test_stale_unix_socket_path_is_recovered(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Startup removes an abandoned Unix socket file left by a crash."""
+        socket_path = tmp_path / "metrics.sock"
+        with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as stale_socket:
+            stale_socket.bind(str(socket_path))
+
+        server = MetricsServer(UnixMetricsAddress(str(socket_path), mode=0o666))
+        await server.start()
+        try:
+            assert socket_path.stat().st_mode & 0o777 == 0o666
+            connector = aiohttp.UnixConnector(path=str(socket_path))
+            async with (
+                aiohttp.ClientSession(connector=connector) as session,
+                session.get("http://crabstero/metrics") as resp,
+            ):
+                assert resp.status == HTTPStatus.OK
+                body = await resp.text()
+                assert "crabstero_build_info" in body
+        finally:
+            await server.stop()
+
+    @requires_unix_socket
+    async def test_active_unix_socket_path_fails(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Startup refuses to replace a Unix socket path that is still in use."""
+        socket_path = tmp_path / "metrics.sock"
+        with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as active_socket:
+            active_socket.bind(str(socket_path))
+            active_socket.listen(1)
+
+            server = MetricsServer(UnixMetricsAddress(str(socket_path)))
+            with pytest.raises(OSError, match="already in use") as exc_info:
+                await server.start()
+
+        assert exc_info.value.errno == errno.EADDRINUSE
+
+    @requires_unix_socket
+    async def test_non_socket_unix_path_fails(self, tmp_path: Path) -> None:
+        """Startup refuses to replace a non-socket path."""
+        socket_path = tmp_path / "metrics.sock"
+        socket_path.write_text("")
+        server = MetricsServer(UnixMetricsAddress(str(socket_path)))
+        with pytest.raises(FileExistsError):
+            await server.start()
+
+    async def test_starting_server_twice_fails(self) -> None:
+        """A running metrics server cannot be started twice."""
+        server = MetricsServer(TcpMetricsAddress("127.0.0.1", 0))
+        await server.start()
+        try:
+            with pytest.raises(RuntimeError, match="already running"):
+                await server.start()
+        finally:
+            await server.stop()