diff --git a/extensions/matrix/src/matrix/actions/limits.test.ts b/extensions/matrix/src/matrix/actions/limits.test.ts
new file mode 100644
index 0000000000..d6c85ab7fa
--- /dev/null
+++ b/extensions/matrix/src/matrix/actions/limits.test.ts
@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+import { resolveMatrixActionLimit } from "./limits.js";
+
+describe("resolveMatrixActionLimit", () => {
+  it("uses fallback for non-finite values", () => {
+    expect(resolveMatrixActionLimit(undefined, 20)).toBe(20);
+    expect(resolveMatrixActionLimit(Number.NaN, 20)).toBe(20);
+  });
+
+  it("normalizes finite numbers to positive integers", () => {
+    expect(resolveMatrixActionLimit(7.9, 20)).toBe(7);
+    expect(resolveMatrixActionLimit(0, 20)).toBe(1);
+    expect(resolveMatrixActionLimit(-3, 20)).toBe(1);
+  });
+});
diff --git a/extensions/matrix/src/matrix/actions/pins.test.ts b/extensions/matrix/src/matrix/actions/pins.test.ts
new file mode 100644
index 0000000000..2b432c1a85
--- /dev/null
+++ b/extensions/matrix/src/matrix/actions/pins.test.ts
@@ -0,0 +1,74 @@
+import type { MatrixClient } from "@vector-im/matrix-bot-sdk";
+import { describe, expect, it, vi } from "vitest";
+import { listMatrixPins, pinMatrixMessage, unpinMatrixMessage } from "./pins.js";
+
+function createPinsClient(seedPinned: string[], knownBodies: Record<string, string> = {}) {
+  let pinned = [...seedPinned];
+  const getRoomStateEvent = vi.fn(async () => ({ pinned: [...pinned] }));
+  const sendStateEvent = vi.fn(
+    async (_roomId: string, _type: string, _key: string, payload: any) => {
+      pinned = [...payload.pinned];
+    },
+  );
+  const getEvent = vi.fn(async (_roomId: string, eventId: string) => {
+    const body = knownBodies[eventId];
+    if (!body) {
+      throw new Error("missing");
+    }
+    return {
+      event_id: eventId,
+      sender: "@alice:example.org",
+      type: "m.room.message",
+      origin_server_ts: 123,
+      content: { msgtype: "m.text", body },
+    };
+  });
+
+  return {
+    client: {
+      getRoomStateEvent,
+      sendStateEvent,
+      getEvent,
+      stop: vi.fn(),
+    } as unknown as MatrixClient,
+    getPinned: () => pinned,
+    sendStateEvent,
+  };
+}
+
+describe("matrix pins actions", () => {
+  it("pins a message once even when asked twice", async () => {
+    const { client, getPinned, sendStateEvent } = createPinsClient(["$a"]);
+
+    const first = await pinMatrixMessage("!room:example.org", "$b", { client });
+    const second = await pinMatrixMessage("!room:example.org", "$b", { client });
+
+    expect(first.pinned).toEqual(["$a", "$b"]);
+    expect(second.pinned).toEqual(["$a", "$b"]);
+    expect(getPinned()).toEqual(["$a", "$b"]);
+    expect(sendStateEvent).toHaveBeenCalledTimes(2);
+  });
+
+  it("unpinds only the selected message id", async () => {
+    const { client, getPinned } = createPinsClient(["$a", "$b", "$c"]);
+
+    const result = await unpinMatrixMessage("!room:example.org", "$b", { client });
+
+    expect(result.pinned).toEqual(["$a", "$c"]);
+    expect(getPinned()).toEqual(["$a", "$c"]);
+  });
+
+  it("lists pinned ids and summarizes only resolvable events", async () => {
+    const { client } = createPinsClient(["$a", "$missing"], { $a: "hello" });
+
+    const result = await listMatrixPins("!room:example.org", { client });
+
+    expect(result.pinned).toEqual(["$a", "$missing"]);
+    expect(result.events).toEqual([
+      expect.objectContaining({
+        eventId: "$a",
+        body: "hello",
+      }),
+    ]);
+  });
+});
diff --git a/extensions/matrix/src/matrix/actions/reactions.test.ts b/extensions/matrix/src/matrix/actions/reactions.test.ts
new file mode 100644
index 0000000000..aab161b54c
--- /dev/null
+++ b/extensions/matrix/src/matrix/actions/reactions.test.ts
@@ -0,0 +1,109 @@
+import type { MatrixClient } from "@vector-im/matrix-bot-sdk";
+import { describe, expect, it, vi } from "vitest";
+import { listMatrixReactions, removeMatrixReactions } from "./reactions.js";
+
+function createReactionsClient(params: {
+  chunk: Array<{
+    event_id?: string;
+    sender?: string;
+    key?: string;
+  }>;
+  userId?: string | null;
+}) {
+  const doRequest = vi.fn(async (_method: string, _path: string, _query: any) => ({
+    chunk: params.chunk.map((item) => ({
+      event_id: item.event_id ?? "",
+      sender: item.sender ?? "",
+      content: item.key
+        ? {
+            "m.relates_to": {
+              rel_type: "m.annotation",
+              event_id: "$target",
+              key: item.key,
+            },
+          }
+        : {},
+    })),
+  }));
+  const getUserId = vi.fn(async () => params.userId ?? null);
+  const redactEvent = vi.fn(async () => undefined);
+
+  return {
+    client: {
+      doRequest,
+      getUserId,
+      redactEvent,
+      stop: vi.fn(),
+    } as unknown as MatrixClient,
+    doRequest,
+    redactEvent,
+  };
+}
+
+describe("matrix reaction actions", () => {
+  it("aggregates reactions by key and unique sender", async () => {
+    const { client, doRequest } = createReactionsClient({
+      chunk: [
+        { event_id: "$1", sender: "@alice:example.org", key: "👍" },
+        { event_id: "$2", sender: "@bob:example.org", key: "👍" },
+        { event_id: "$3", sender: "@alice:example.org", key: "👎" },
+        { event_id: "$4", sender: "@bot:example.org" },
+      ],
+      userId: "@bot:example.org",
+    });
+
+    const result = await listMatrixReactions("!room:example.org", "$msg", { client, limit: 2.9 });
+
+    expect(doRequest).toHaveBeenCalledWith(
+      "GET",
+      expect.stringContaining("/rooms/!room%3Aexample.org/relations/%24msg/"),
+      expect.objectContaining({ limit: 2 }),
+    );
+    expect(result).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({
+          key: "👍",
+          count: 2,
+          users: expect.arrayContaining(["@alice:example.org", "@bob:example.org"]),
+        }),
+        expect.objectContaining({
+          key: "👎",
+          count: 1,
+          users: ["@alice:example.org"],
+        }),
+      ]),
+    );
+  });
+
+  it("removes only current-user reactions matching emoji filter", async () => {
+    const { client, redactEvent } = createReactionsClient({
+      chunk: [
+        { event_id: "$1", sender: "@me:example.org", key: "👍" },
+        { event_id: "$2", sender: "@me:example.org", key: "👎" },
+        { event_id: "$3", sender: "@other:example.org", key: "👍" },
+      ],
+      userId: "@me:example.org",
+    });
+
+    const result = await removeMatrixReactions("!room:example.org", "$msg", {
+      client,
+      emoji: "👍",
+    });
+
+    expect(result).toEqual({ removed: 1 });
+    expect(redactEvent).toHaveBeenCalledTimes(1);
+    expect(redactEvent).toHaveBeenCalledWith("!room:example.org", "$1");
+  });
+
+  it("returns removed=0 when current user id is unavailable", async () => {
+    const { client, redactEvent } = createReactionsClient({
+      chunk: [{ event_id: "$1", sender: "@me:example.org", key: "👍" }],
+      userId: null,
+    });
+
+    const result = await removeMatrixReactions("!room:example.org", "$msg", { client });
+
+    expect(result).toEqual({ removed: 0 });
+    expect(redactEvent).not.toHaveBeenCalled();
+  });
+});