diff --git a/.github/workflows/test-base.yml b/.github/workflows/test-base.yml
index d2640374..0e06eb02 100644
--- a/.github/workflows/test-base.yml
+++ b/.github/workflows/test-base.yml
@@ -45,6 +45,9 @@ jobs:
           pnpm lint
           pnpm publint
 
+      - name: Run Typecheck
+        run: pnpm typecheck
+
       - uses: ./.github/actions/setup-playwright
 
       # Needed for additional browsers that Vitest unit tests use.
diff --git a/oxlint.config.ts b/oxlint.config.ts
index 53d69b54..30fae4cc 100644
--- a/oxlint.config.ts
+++ b/oxlint.config.ts
@@ -5,8 +5,20 @@ export default defineConfig({
     typeAware: true,
   },
 
+  plugins: [
+    "import",
+
+    // Defaults:
+    "eslint",
+    "typescript",
+    "unicorn",
+    "oxc",
+  ],
+
   rules: {
     "unicorn/prefer-node-protocol": "error",
+    "typescript/consistent-type-imports": ["error", { fixStyle: "inline-type-imports" }],
+    "import/no-duplicates": "error",
   },
 
   overrides: [
diff --git a/package.json b/package.json
index 8f442f81..f611a84c 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,8 @@
     "dev:server": "node test-server/server",
     "lint": "oxlint",
     "fmt": "oxfmt",
-    "publint": "pnpm -r --parallel --filter !@chromatic-com/shared-e2e exec publint",
+    "publint": "pnpm -r --parallel --no-bail --filter !@chromatic-com/shared-e2e exec publint",
+    "typecheck": "pnpm -r --parallel --no-bail run typecheck",
     "prepare": "husky install",
     "release": "pnpm build && pnpm changeset publish",
     "test:unit": "vitest run --configLoader=runner",
diff --git a/packages/cypress/package.json b/packages/cypress/package.json
index f866a908..ac53940f 100644
--- a/packages/cypress/package.json
+++ b/packages/cypress/package.json
@@ -39,6 +39,7 @@
   },
   "scripts": {
     "build": "tsdown",
+    "typecheck": "tsc --noEmit",
     "test:cypress": "start-server-and-test 'pnpm --filter @chromaui/chromatic-e2e dev:server' 3000 'pnpm test:do-cypress'",
     "test:do-cypress": "ELECTRON_EXTRA_LAUNCH_ARGS=--remote-debugging-port=8192 cypress run --project tests",
     "test:unit": "pnpm --filter @chromaui/chromatic-e2e run test:unit --project Cypress"
@@ -56,7 +57,8 @@
     "@storybook/server-webpack5": "10.2.13",
     "cypress": "15.18.0",
     "start-server-and-test": "^2.0.3",
-    "tsdown": "^0.22.14"
+    "tsdown": "^0.22.14",
+    "typescript": "^5.9.3"
   },
   "peerDependencies": {
     "cypress": ">=15.10.0"
diff --git a/packages/cypress/src/commands.ts b/packages/cypress/src/commands.ts
index 7e4c5efc..7ac079c9 100644
--- a/packages/cypress/src/commands.ts
+++ b/packages/cypress/src/commands.ts
@@ -1,5 +1,5 @@
 import { takeSnapshot as takeChromaticSnapshot } from "./takeSnapshot";
-import { CypressSnapshot } from "./types";
+import { type CypressSnapshot } from "./types";
 
 declare global {
   // eslint-disable-next-line @typescript-eslint/no-namespace
diff --git a/packages/cypress/src/index.ts b/packages/cypress/src/index.ts
index 48dc6136..a9df58f9 100644
--- a/packages/cypress/src/index.ts
+++ b/packages/cypress/src/index.ts
@@ -1,13 +1,13 @@
 import {
   ResourceArchiver,
   writeTestResult,
-  ChromaticStorybookParameters,
-  ResourceArchive,
-  Viewport,
+  type ChromaticStorybookParameters,
+  type ResourceArchive,
+  type Viewport,
 } from "@chromatic-com/shared-e2e";
 import CDP, { Version } from "chrome-remote-interface";
 
-import { CypressSnapshot } from "./types";
+import { type CypressSnapshot } from "./types";
 
 interface WriteParams {
   testTitlePath: string[];
diff --git a/packages/cypress/src/support.ts b/packages/cypress/src/support.ts
index fdb47dd8..69db75d8 100644
--- a/packages/cypress/src/support.ts
+++ b/packages/cypress/src/support.ts
@@ -1,6 +1,6 @@
 import "./commands";
 import { takeSnapshot } from "./takeSnapshot";
-import { CypressSnapshot } from "./types";
+import { type CypressSnapshot } from "./types";
 
 const buildChromaticParams = (expose: Cypress.Cypress["expose"]) => ({
   ...(expose("diffThreshold") && {
diff --git a/packages/cypress/src/takeSnapshot.ts b/packages/cypress/src/takeSnapshot.ts
index 9be3a586..7ff0a26b 100644
--- a/packages/cypress/src/takeSnapshot.ts
+++ b/packages/cypress/src/takeSnapshot.ts
@@ -1,7 +1,7 @@
 import { createMirror, snapshot } from "@chromaui/rrweb-snapshot";
 import type { serializedNodeWithId } from "@rrweb/types";
 
-import { CypressSnapshot } from "./types";
+import { type CypressSnapshot } from "./types";
 
 export const takeSnapshot = (
   doc: Document,
diff --git a/packages/cypress/tsconfig.json b/packages/cypress/tsconfig.json
index 6b2498b6..d2a1d3da 100644
--- a/packages/cypress/tsconfig.json
+++ b/packages/cypress/tsconfig.json
@@ -3,6 +3,6 @@
   "compilerOptions": {
     "types": ["node", "cypress"]
   },
-  "include": ["src", "scripts", "vitest.config.ts"],
-  "exclude": ["node_modules", "dist"]
+  "include": ["src", "scripts", "tests", "embedded.test.ts", "vitest.config.ts"],
+  "exclude": ["node_modules", "dist", "tests/cypress/test-downloads"]
 }
diff --git a/packages/playwright/package.json b/packages/playwright/package.json
index 67272b35..eee16864 100644
--- a/packages/playwright/package.json
+++ b/packages/playwright/package.json
@@ -36,6 +36,7 @@
   },
   "scripts": {
     "build": "tsdown",
+    "typecheck": "tsc --noEmit",
     "test:playwright": "playwright test",
     "test:unit": "pnpm --filter @chromaui/chromatic-e2e run test:unit --project Playwright"
   },
@@ -54,7 +55,8 @@
     "playwright": "^1.46.1",
     "playwright-core": "^1.46.1",
     "ts-dedent": "^2.2.0",
-    "tsdown": "^0.22.14"
+    "tsdown": "^0.22.14",
+    "typescript": "^5.9.3"
   },
   "peerDependencies": {
     "@playwright/test": "^1.0.0"
diff --git a/packages/playwright/src/createResourceArchive.test.ts b/packages/playwright/src/createResourceArchive.test.ts
index a6ac593c..0e675d48 100644
--- a/packages/playwright/src/createResourceArchive.test.ts
+++ b/packages/playwright/src/createResourceArchive.test.ts
@@ -1,8 +1,8 @@
-import { Server } from "node:http";
+import { type Server } from "node:http";
 
 import { logger } from "@chromatic-com/shared-e2e";
 import express, { type Request } from "express";
-import { Browser, chromium, Page } from "playwright";
+import { type Browser, chromium, type Page } from "playwright";
 import { dedent } from "ts-dedent";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
diff --git a/packages/playwright/src/createResourceArchive.ts b/packages/playwright/src/createResourceArchive.ts
index 9af9a6cf..70927070 100644
--- a/packages/playwright/src/createResourceArchive.ts
+++ b/packages/playwright/src/createResourceArchive.ts
@@ -1,9 +1,9 @@
 import {
   ResourceArchiver,
-  ResourceArchive,
+  type ResourceArchive,
   DEFAULT_GLOBAL_RESOURCE_ARCHIVE_TIMEOUT_MS,
   logger,
-  HttpCredentials,
+  type HttpCredentials,
 } from "@chromatic-com/shared-e2e";
 import type { Page } from "@playwright/test";
 
diff --git a/packages/playwright/src/makeTest.test.ts b/packages/playwright/src/makeTest.test.ts
index 2e184498..200d0012 100644
--- a/packages/playwright/src/makeTest.test.ts
+++ b/packages/playwright/src/makeTest.test.ts
@@ -1,5 +1,5 @@
-import { Browser, chromium, Page } from "playwright";
-import { TestInfo } from "playwright/test";
+import { type Browser, chromium, type Page } from "playwright";
+import { type TestInfo } from "playwright/test";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 import { performChromaticSnapshot } from "./makeTest";
diff --git a/packages/playwright/src/takeSnapshot.test.ts b/packages/playwright/src/takeSnapshot.test.ts
index 67952048..d447239e 100644
--- a/packages/playwright/src/takeSnapshot.test.ts
+++ b/packages/playwright/src/takeSnapshot.test.ts
@@ -1,6 +1,6 @@
-import { NodeType, serializedElementNodeWithId } from "@rrweb/types";
-import { Page } from "playwright";
-import { TestInfo } from "playwright/test";
+import { NodeType, type serializedElementNodeWithId } from "@rrweb/types";
+import { type Page } from "playwright";
+import { type TestInfo } from "playwright/test";
 import { beforeEach, describe, expect, it } from "vitest";
 
 import { chromaticSnapshots, takeSnapshot } from "./takeSnapshot";
diff --git a/packages/playwright/src/types.test-d.ts b/packages/playwright/src/types.test-d.ts
index d7005594..b54224e5 100644
--- a/packages/playwright/src/types.test-d.ts
+++ b/packages/playwright/src/types.test-d.ts
@@ -1,4 +1,4 @@
-import { Page, TestInfo } from "@playwright/test";
+import { type Page, type TestInfo } from "@playwright/test";
 import { expectTypeOf, test } from "vitest";
 
 import * as publicAPI from "../dist/index.mjs";
diff --git a/packages/playwright/tsconfig.json b/packages/playwright/tsconfig.json
index 3e40d2fd..b4f48f94 100644
--- a/packages/playwright/tsconfig.json
+++ b/packages/playwright/tsconfig.json
@@ -1,4 +1,4 @@
 {
   "extends": "../../tsconfig.json",
-  "include": ["src", "vitest.config.ts"]
+  "include": ["src", "tests", "embedded.test.ts", "playwright.config.ts", "vitest.config.ts"]
 }
diff --git a/packages/shared/package.json b/packages/shared/package.json
index dd2983f0..1bb03bde 100644
--- a/packages/shared/package.json
+++ b/packages/shared/package.json
@@ -16,7 +16,8 @@
     "./test-utils": "./src/test-utils"
   },
   "scripts": {
-    "test:unit": "pnpm --filter @chromaui/chromatic-e2e run test:unit --project Shared"
+    "test:unit": "pnpm --filter @chromaui/chromatic-e2e run test:unit --project Shared",
+    "typecheck": "tsc --noEmit"
   },
   "dependencies": {
     "@chromaui/rrweb-snapshot": "2.0.0-alpha.19-noAbsolute",
@@ -32,7 +33,7 @@
     "@testing-library/react": "^12.0.0",
     "@testing-library/user-event": "^13.2.1",
     "@types/node-fetch": "^2.6.6",
-    "mime": "^3.0.0",
+    "mime": "^4.0.0",
     "node-fetch": "2",
     "playwright": "^1.46.1",
     "playwright-core": "^1.46.1",
diff --git a/packages/shared/src/types.ts b/packages/shared/src/types.ts
index e3f17036..0473a8f2 100644
--- a/packages/shared/src/types.ts
+++ b/packages/shared/src/types.ts
@@ -1,6 +1,6 @@
-import { NodeType, serializedNodeWithId } from "@rrweb/types";
+import { type NodeType, type serializedNodeWithId } from "@rrweb/types";
 
-import { Viewport } from "./utils/viewport";
+import { type Viewport } from "./utils/viewport";
 
 export interface ChromaticConfig {
   /** https://www.chromatic.com/docs/delay/ */
diff --git a/packages/shared/src/utils/filePaths.test.ts b/packages/shared/src/utils/filePaths.test.ts
index c7910c56..f0457bc3 100644
--- a/packages/shared/src/utils/filePaths.test.ts
+++ b/packages/shared/src/utils/filePaths.test.ts
@@ -3,8 +3,14 @@ import fsPromises from "node:fs/promises";
 
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
-import { archivesDir, ensureDir, outputFile, outputJSONFile, truncateFileName } from "./filePaths";
-import { removeLocalhostFromBaseUrl } from "./filePaths";
+import {
+  archivesDir,
+  ensureDir,
+  outputFile,
+  outputJSONFile,
+  truncateFileName,
+  removeLocalhostFromBaseUrl,
+} from "./filePaths";
 
 vi.mock("fs");
 vi.mock("fs/promises");
diff --git a/packages/shared/src/utils/nodes.ts b/packages/shared/src/utils/nodes.ts
index 60d29cbc..1fd75586 100644
--- a/packages/shared/src/utils/nodes.ts
+++ b/packages/shared/src/utils/nodes.ts
@@ -1,4 +1,4 @@
-import { NodeType, serializedNodeWithId } from "@rrweb/types";
+import { NodeType, type serializedNodeWithId } from "@rrweb/types";
 
 import type { SerializedIframeNode } from "../types";
 
diff --git a/packages/shared/src/write-archive/dom-snapshot.test.ts b/packages/shared/src/write-archive/dom-snapshot.test.ts
index eb70dcd0..3dc45762 100644
--- a/packages/shared/src/write-archive/dom-snapshot.test.ts
+++ b/packages/shared/src/write-archive/dom-snapshot.test.ts
@@ -1,4 +1,4 @@
-import { serializedNodeWithId } from "@rrweb/types";
+import { type serializedNodeWithId } from "@rrweb/types";
 import { describe, expect, it } from "vitest";
 
 import { DOMSnapshot } from "./dom-snapshot";
@@ -432,13 +432,13 @@ describe("DOMSnapshot", () => {
     it("maps pseudoClassIds", async () => {
       const domSnapshot = new DOMSnapshot({
         snapshot,
-        pseudoClassIds: { hover: [2, 3, 4], focus: [5, 6, 7], active: [8, 9, 10] },
+        pseudoClassIds: { ":hover": [2, 3, 4], ":focus": [5, 6, 7], ":active": [8, 9, 10] },
       });
 
       const mappedSnapshot = await domSnapshot.mapAssetPaths(sourceMap);
 
       expect(mappedSnapshot).toEqual(
-        `{"snapshot":${expectedMappedSnapshot},"pseudoClassIds":{"hover":[2,3,4],"focus":[5,6,7],"active":[8,9,10]}}`,
+        `{"snapshot":${expectedMappedSnapshot},"pseudoClassIds":{":hover":[2,3,4],":focus":[5,6,7],":active":[8,9,10]}}`,
       );
     });
   });
diff --git a/packages/shared/src/write-archive/index.test.ts b/packages/shared/src/write-archive/index.test.ts
index 23a64f73..30d6518e 100644
--- a/packages/shared/src/write-archive/index.test.ts
+++ b/packages/shared/src/write-archive/index.test.ts
@@ -49,13 +49,15 @@ describe("writeTestResult", () => {
         home: {
           snapshot: Buffer.from(JSON.stringify(snapshotJson)),
           viewport: { height: 800, width: 800 },
+          colorScheme: "dark",
+          pseudoClassIds: {},
         },
       },
       { "http://localhost:3000/home": { statusCode: 200, body: Buffer.from("Chromatic") } },
       {
         diffThreshold: 5,
         pauseAnimationAtEnd: true,
-      },
+      } as any,
     );
     expect(filePaths.ensureDir).toHaveBeenCalledTimes(1);
     expect(filePaths.outputFile).toHaveBeenCalledTimes(2);
@@ -70,6 +72,7 @@ describe("writeTestResult", () => {
             parameters: {
               __id: "file-test-story--home",
               chromatic: {
+                colorScheme: "dark",
                 diffThreshold: 5,
                 pauseAnimationAtEnd: true,
                 modes: { w800h800: { viewport: "w800h800" } },
@@ -122,6 +125,8 @@ describe("writeTestResult", () => {
         home: {
           snapshot: Buffer.from(JSON.stringify(snapshotJson)),
           viewport: { height: 800, width: 800 },
+          colorScheme: "dark",
+          pseudoClassIds: {},
         },
       },
       {
@@ -135,7 +140,7 @@ describe("writeTestResult", () => {
           contentType: "image/png",
         },
       },
-      {},
+      {} as any,
     );
 
     expect(filePaths.ensureDir).toHaveBeenCalledTimes(1);
@@ -145,7 +150,7 @@ describe("writeTestResult", () => {
       resolve(
         "./test-results/chromatic-archives/archive/file-toy-story-home.w800h800.snapshot.json",
       ),
-      JSON.stringify({ snapshot: expectedMappedJson }),
+      JSON.stringify({ snapshot: expectedMappedJson, pseudoClassIds: {} }),
     );
   });
 
@@ -161,10 +166,12 @@ describe("writeTestResult", () => {
         home: {
           snapshot: Buffer.from(JSON.stringify(snapshotJson)),
           viewport: { height: 800, width: 800 },
+          colorScheme: "dark",
+          pseudoClassIds: {},
         },
       },
       { "http://localhost:3000/home": { statusCode: 200, body: Buffer.from("Chromatic") } },
-      {},
+      {} as any,
     );
     expect(filePaths.ensureDir).toHaveBeenCalledTimes(1);
     expect(filePaths.outputFile).toHaveBeenCalledTimes(2);
@@ -183,10 +190,15 @@ describe("writeTestResult", () => {
         pageUrl: "http://localhost:3000/",
       },
       {
-        home: { snapshot: Buffer.from(JSON.stringify({})), viewport: { height: 800, width: 800 } },
+        home: {
+          snapshot: Buffer.from(JSON.stringify({})),
+          viewport: { height: 800, width: 800 },
+          colorScheme: "dark",
+          pseudoClassIds: {},
+        },
       },
       {},
-      {},
+      {} as any,
     );
 
     const { title } = vi.mocked(filePaths.outputJSONFile).mock.calls[0][1];
@@ -207,6 +219,8 @@ describe("writeTestResult", () => {
           home: {
             snapshot: Buffer.from(JSON.stringify(snapshotJson)),
             viewport: { height: 800, width: 800 },
+            colorScheme: "dark",
+            pseudoClassIds: {},
           },
         },
         {
@@ -216,7 +230,7 @@ describe("writeTestResult", () => {
               body: Buffer.from("Chromatic"),
             },
         },
-        {},
+        {} as any,
       );
 
       expect(filePaths.outputFile).toHaveBeenCalledWith(
@@ -238,10 +252,12 @@ describe("writeTestResult", () => {
           home: {
             snapshot: Buffer.from(JSON.stringify(snapshotJson)),
             viewport: { height: 800, width: 800 },
+            colorScheme: "dark",
+            pseudoClassIds: {},
           },
         },
         { "http://localhost:3000/home": { statusCode: 200, body: Buffer.from("Chromatic") } },
-        {},
+        {} as any,
       );
       expect(filePaths.outputJSONFile).toHaveBeenCalledWith(
         expect.anything(),
@@ -266,10 +282,12 @@ describe("writeTestResult", () => {
           home: {
             snapshot: Buffer.from(JSON.stringify(snapshotJson)),
             viewport: { height: 800, width: 800 },
+            colorScheme: "dark",
+            pseudoClassIds: {},
           },
         },
         { "http://localhost:3000/home": { statusCode: 200, body: Buffer.from("Chromatic") } },
-        {},
+        {} as any,
       );
       expect(filePaths.outputJSONFile).toHaveBeenCalledWith(
         expect.anything(),
@@ -290,10 +308,12 @@ describe("writeTestResult", () => {
           home: {
             snapshot: Buffer.from(JSON.stringify(snapshotJson)),
             viewport: { height: 800, width: 800 },
+            colorScheme: "dark",
+            pseudoClassIds: {},
           },
         },
         { "http://localhost:3000/home": { statusCode: 200, body: Buffer.from("Chromatic") } },
-        {},
+        {} as any,
       );
       expect(filePaths.outputJSONFile).toHaveBeenCalledWith(
         expect.anything(),
@@ -314,10 +334,12 @@ describe("writeTestResult", () => {
           home: {
             snapshot: Buffer.from(JSON.stringify(snapshotJson)),
             viewport: { height: 800, width: 800 },
+            colorScheme: "dark",
+            pseudoClassIds: {},
           },
         },
         { "http://localhost:3000/home": { statusCode: 200, body: Buffer.from("Chromatic") } },
-        {},
+        {} as any,
       );
       expect(filePaths.outputJSONFile).toHaveBeenCalledWith(
         expect.anything(),
@@ -338,10 +360,12 @@ describe("writeTestResult", () => {
           home: {
             snapshot: Buffer.from(JSON.stringify(snapshotJson)),
             viewport: { height: 800, width: 800 },
+            colorScheme: "dark",
+            pseudoClassIds: {},
           },
         },
         { "http://localhost:3000/home": { statusCode: 200, body: Buffer.from("Chromatic") } },
-        {},
+        {} as any,
       );
       expect(filePaths.outputJSONFile).toHaveBeenCalledWith(
         expect.anything(),
diff --git a/packages/shared/src/write-archive/snapshot-files.ts b/packages/shared/src/write-archive/snapshot-files.ts
index a59ab023..d8e4f619 100644
--- a/packages/shared/src/write-archive/snapshot-files.ts
+++ b/packages/shared/src/write-archive/snapshot-files.ts
@@ -1,5 +1,5 @@
 import { MAX_FILE_NAME_BYTE_LENGTH, truncateFileName } from "../utils/filePaths";
-import { Viewport, viewportToString } from "../utils/viewport";
+import { type Viewport, viewportToString } from "../utils/viewport";
 import { sanitize } from "./storybook-sanitize";
 
 const SNAPSHOT_FILE_EXT = "snapshot.json";
diff --git a/packages/shared/src/write-archive/stories-files.test.ts b/packages/shared/src/write-archive/stories-files.test.ts
index b349bd0a..69076e0b 100644
--- a/packages/shared/src/write-archive/stories-files.test.ts
+++ b/packages/shared/src/write-archive/stories-files.test.ts
@@ -1,6 +1,6 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";
 
-import { ChromaticStorybookParameters } from "../types";
+import type { ChromaticStorybookParameters, DOMSnapshots } from "../types";
 import * as storiesFiles from "./stories-files";
 
 vi.mock("fs/promises");
@@ -42,10 +42,21 @@ describe("storiesFileName", () => {
 describe("createStories", () => {
   it("creates stories file JSON from DOM snapshots", () => {
     const title = "some test title";
-    const domSnapshots = {
-      "snapshot 1": { snapshot: Buffer.from("n/a"), viewport: { width: 100, height: 200 } },
-      "another snapshot": { snapshot: Buffer.from("n/a"), viewport: { width: 300, height: 400 } },
+    const domSnapshots: DOMSnapshots = {
+      "snapshot 1": {
+        snapshot: Buffer.from("n/a"),
+        viewport: { width: 100, height: 200 },
+        colorScheme: "dark",
+        pseudoClassIds: {},
+      },
+      "another snapshot": {
+        snapshot: Buffer.from("n/a"),
+        viewport: { width: 300, height: 400 },
+        colorScheme: "dark",
+        pseudoClassIds: {},
+      },
     };
+
     const chromaticParams: ChromaticStorybookParameters = {
       delay: 200,
       pauseAnimationAtEnd: true,
@@ -63,6 +74,7 @@ describe("createStories", () => {
             __id: "some-test-title--snapshot-1",
             server: { id: "some-test-title-snapshot-1" },
             chromatic: {
+              colorScheme: "dark",
               delay: 200,
               pauseAnimationAtEnd: true,
               modes: {
@@ -93,6 +105,7 @@ describe("createStories", () => {
             __id: "some-test-title--another-snapshot",
             server: { id: "some-test-title-another-snapshot" },
             chromatic: {
+              colorScheme: "dark",
               delay: 200,
               pauseAnimationAtEnd: true,
               modes: {
@@ -137,6 +150,8 @@ describe("createStories", () => {
         "\n\n\r\rSnapshot\nName\rWith\r\nNewlines\n\r\r\n": {
           snapshot: Buffer.from("n/a"),
           viewport: { width: 100, height: 200 },
+          colorScheme: "dark",
+          pseudoClassIds: {},
         },
       },
       {},
diff --git a/packages/shared/src/write-archive/stories-files.ts b/packages/shared/src/write-archive/stories-files.ts
index 215575ca..4056272e 100644
--- a/packages/shared/src/write-archive/stories-files.ts
+++ b/packages/shared/src/write-archive/stories-files.ts
@@ -2,7 +2,7 @@ import { storyNameFromExport, toId } from "storybook/internal/csf";
 
 import type { ChromaticStorybookParameters, DOMSnapshots } from "../types";
 import { MAX_FILE_NAME_BYTE_LENGTH, truncateFileName } from "../utils/filePaths";
-import { Viewport, viewportToString } from "../utils/viewport";
+import { type Viewport, viewportToString } from "../utils/viewport";
 import { snapshotId } from "./snapshot-files";
 import { collapseNewlines, sanitize } from "./storybook-sanitize";
 
diff --git a/packages/vitest/package.json b/packages/vitest/package.json
index 69f14e41..3161986e 100644
--- a/packages/vitest/package.json
+++ b/packages/vitest/package.json
@@ -38,6 +38,7 @@
   },
   "scripts": {
     "build": "tsdown",
+    "typecheck": "tsc --noEmit",
     "test:unit": "pnpm --filter @chromaui/chromatic-e2e run test:unit --project 'Vitest Unit' --project 'Vitest Browser'",
     "test:vitest": "vitest --config test/vitest.config.e2e.ts"
   },
@@ -58,6 +59,7 @@
     "extend-to-be-announced": "2.0.0",
     "msw": "^2.12.10",
     "tsdown": "^0.22.14",
+    "typescript": "^5.9.3",
     "vitest": "^5.0.0"
   },
   "peerDependencies": {
diff --git a/packages/vitest/src/browser/getCurrentTest.ts b/packages/vitest/src/browser/getCurrentTest.ts
index 07f5535f..569bb3b4 100644
--- a/packages/vitest/src/browser/getCurrentTest.ts
+++ b/packages/vitest/src/browser/getCurrentTest.ts
@@ -1,6 +1,6 @@
 import * as vitest from "vitest";
 
-import { InternalTestContext } from "../types";
+import type { InternalTestContext } from "../types";
 
 export type Test = ReturnType<typeof vitest.TestRunner.getCurrentTest> &
   InternalTestContext["task"];
@@ -22,5 +22,9 @@ async function resolveHooks() {
   }
 
   // Fallback to older API. Using this with 4.1.0 logs deprecation warning.
-  return await import("vitest/suite");
+  // @ts-expect-error -- does not exist in vitest@5
+  return (await import("vitest/suite")) as Pick<
+    typeof vitest.TestRunner,
+    "getCurrentTest" | "getCurrentSuite"
+  >;
 }
diff --git a/packages/vitest/src/browser/public/takeSnapshot.ts b/packages/vitest/src/browser/public/takeSnapshot.ts
index f99a6e26..0ecc8135 100644
--- a/packages/vitest/src/browser/public/takeSnapshot.ts
+++ b/packages/vitest/src/browser/public/takeSnapshot.ts
@@ -1,6 +1,6 @@
 import { type DOMSnapshots } from "@chromatic-com/shared-e2e";
 import { snapshot as rrwebSnapshot, createMirror } from "@chromaui/rrweb-snapshot";
-import { serializedNodeWithId } from "@rrweb/types";
+import { type serializedNodeWithId } from "@rrweb/types";
 import { assert } from "vitest";
 import { commands } from "vitest/browser";
 
diff --git a/packages/vitest/src/node/commands.browser.test.ts b/packages/vitest/src/node/commands.browser.test.ts
index 461dab60..7b796d59 100644
--- a/packages/vitest/src/node/commands.browser.test.ts
+++ b/packages/vitest/src/node/commands.browser.test.ts
@@ -1,7 +1,7 @@
 import { test, expect } from "vitest";
 import { commands } from "vitest/browser";
 
-import { InternalTestContext } from "../types";
+import { type InternalTestContext } from "../types";
 
 test<InternalTestContext>("setupFile is registered", async (context) => {
   expect(context.task.meta.__chromatic_isRegistered).toBe(true);
diff --git a/packages/vitest/src/node/commands.ts b/packages/vitest/src/node/commands.ts
index 7d0f7eea..472aedb6 100644
--- a/packages/vitest/src/node/commands.ts
+++ b/packages/vitest/src/node/commands.ts
@@ -21,8 +21,7 @@ import {
 } from "../types";
 import { NetworkIdleTracker } from "./NetworkIdleTracker";
 import { ChromaticReporter } from "./reporter";
-import { trackEvent } from "./telemetry";
-import { TelemetryReporter } from "./telemetry";
+import { trackEvent, TelemetryReporter } from "./telemetry";
 import { WebpackStatsReporter } from "./webpack-stats-reporter";
 
 type TestID = TestCase["id"];
diff --git a/packages/vitest/src/node/plugin.ts b/packages/vitest/src/node/plugin.ts
index d0053c49..6bf0714f 100644
--- a/packages/vitest/src/node/plugin.ts
+++ b/packages/vitest/src/node/plugin.ts
@@ -18,8 +18,8 @@ import {
   trackEvent as _trackEvent,
   type EventType,
   type TelemetryEvent,
+  TelemetryReporter,
 } from "./telemetry";
-import { TelemetryReporter } from "./telemetry";
 import { mergePreviewStats, WebpackStatsReporter } from "./webpack-stats-reporter";
 
 const DEFAULT_TAG_DESCRIPTION = "Visual Regression Tests for `@chromatic-com/vitest`";
@@ -239,7 +239,7 @@ function withErrorTracking(
 ): Vite.Plugin["configureVitest"] {
   return async (context) => {
     try {
-      // oxlint-disable-next-line typescript/await-thenable -- this is really promise
+      // eslint-disable-next-line typescript/await-thenable -- this is really promise
       return await configureVitest(context);
     } catch (error) {
       _trackEvent(
diff --git a/packages/vitest/src/node/reporter.ts b/packages/vitest/src/node/reporter.ts
index d030547a..d2062cf8 100644
--- a/packages/vitest/src/node/reporter.ts
+++ b/packages/vitest/src/node/reporter.ts
@@ -1,8 +1,7 @@
 import { relative, resolve } from "node:path";
 
 import colors from "tinyrainbow";
-import { TestCase, TestModule, Vitest } from "vitest/node";
-import { Reporter } from "vitest/reporters";
+import type { Reporter, TestCase, TestModule, Vitest } from "vitest/node";
 
 import { DEFAULT_OUTPUT_DIR } from "../constants";
 import { type ResolvedOptions } from "../types";
diff --git a/packages/vitest/src/node/telemetry/reporter.ts b/packages/vitest/src/node/telemetry/reporter.ts
index 88c31dac..7f3ab033 100644
--- a/packages/vitest/src/node/telemetry/reporter.ts
+++ b/packages/vitest/src/node/telemetry/reporter.ts
@@ -1,5 +1,4 @@
-import { type Vitest } from "vitest/node";
-import { type Reporter } from "vitest/reporters";
+import { type Reporter, type Vitest } from "vitest/node";
 
 import { type ResolvedOptions } from "../../types";
 import { trackEvent } from "./track";
diff --git a/packages/vitest/src/node/telemetry/sanitize.test.ts b/packages/vitest/src/node/telemetry/sanitize.test.ts
index e7e83251..bf8da35b 100644
--- a/packages/vitest/src/node/telemetry/sanitize.test.ts
+++ b/packages/vitest/src/node/telemetry/sanitize.test.ts
@@ -105,9 +105,9 @@ describe("Windows paths", () => {
 
     vi.spyOn(process, "cwd").mockReturnValue(WINDOWS_MOCK_CWD);
     vi.doMock("node:os", () => ({ homedir: () => WINDOWS_MOCK_HOMEDIR }));
-    vi.doMock("node:path", async (importOriginal) => ({
-      ...(await importOriginal<typeof import("node:path")>()),
-      sep: "\\",
+    vi.doMock(import("node:path"), async (importOriginal) => ({
+      ...(await importOriginal()),
+      sep: "\\" as const,
     }));
 
     return function afterEach() {
diff --git a/packages/vitest/src/node/telemetry/types.ts b/packages/vitest/src/node/telemetry/types.ts
index 2e0a20f8..0069837b 100644
--- a/packages/vitest/src/node/telemetry/types.ts
+++ b/packages/vitest/src/node/telemetry/types.ts
@@ -1,7 +1,7 @@
 /** These types are consumed by both browser and node sides */
 
 import type { ChromaticNamespace, ConfigureOptions } from "../../types";
-import { EVENT_TYPE_PREFIX } from "./constants";
+import { type EVENT_TYPE_PREFIX } from "./constants";
 
 export type EventType = keyof TelemetryPayloads;
 
diff --git a/packages/vitest/src/node/webpack-stats-reporter.ts b/packages/vitest/src/node/webpack-stats-reporter.ts
index 2c10302d..ddb072a1 100644
--- a/packages/vitest/src/node/webpack-stats-reporter.ts
+++ b/packages/vitest/src/node/webpack-stats-reporter.ts
@@ -2,8 +2,14 @@ import { existsSync, readFileSync } from "node:fs";
 import { mkdir, readdir, readFile, rm, writeFile } from "node:fs/promises";
 import { dirname, relative, resolve, sep } from "node:path";
 
-import { isCSSRequest, type TestCase, type TestModule, type Vite, type Vitest } from "vitest/node";
-import type { Reporter } from "vitest/reporters";
+import {
+  type Reporter,
+  isCSSRequest,
+  type TestCase,
+  type TestModule,
+  type Vite,
+  type Vitest,
+} from "vitest/node";
 
 import type { ResolvedOptions } from "../types";
 import { trackEvent } from "./telemetry";
diff --git a/packages/vitest/test/css-pseudo-states.test.ts b/packages/vitest/test/css-pseudo-states.test.ts
index 11190192..71299574 100644
--- a/packages/vitest/test/css-pseudo-states.test.ts
+++ b/packages/vitest/test/css-pseudo-states.test.ts
@@ -1,7 +1,7 @@
 import { assert, expect } from "vitest";
 import { commands, page, userEvent } from "vitest/browser";
 
-import { configure, takeSnapshot } from "../dist";
+import { configure, takeSnapshot } from "../dist/index.mjs";
 import { test } from "./utils/browser";
 
 configure({ disableAutoSnapshot: true });
diff --git a/packages/vitest/test/duplicate-test-names.test.ts b/packages/vitest/test/duplicate-test-names.test.ts
index 2ac8d973..3e76206e 100644
--- a/packages/vitest/test/duplicate-test-names.test.ts
+++ b/packages/vitest/test/duplicate-test-names.test.ts
@@ -1,4 +1,4 @@
-import { configure, takeSnapshot } from "../dist";
+import { configure, takeSnapshot } from "../dist/index.mjs";
 import { test } from "./utils/browser";
 
 test.each(["one", "two"])("duplicate test name", async (label) => {
diff --git a/packages/vitest/test/embeds.test.ts b/packages/vitest/test/embeds.test.ts
index d46a3a61..ae01fb0d 100644
--- a/packages/vitest/test/embeds.test.ts
+++ b/packages/vitest/test/embeds.test.ts
@@ -1,7 +1,7 @@
 import { expect } from "vitest";
-import { Locator, locators, page } from "vitest/browser";
+import { type Locator, locators, page } from "vitest/browser";
 
-import { takeSnapshot, configure } from "../dist";
+import { takeSnapshot, configure } from "../dist/index.mjs";
 import { test } from "./utils/browser";
 
 test("same-origin embed page loads", async ({ goTo }) => {
diff --git a/packages/vitest/test/manual-snapshots.test.ts b/packages/vitest/test/manual-snapshots.test.ts
index d1ff9c04..10e15434 100644
--- a/packages/vitest/test/manual-snapshots.test.ts
+++ b/packages/vitest/test/manual-snapshots.test.ts
@@ -1,7 +1,7 @@
 import { expect } from "vitest";
 import { page } from "vitest/browser";
 
-import { configure, takeSnapshot } from "../dist";
+import { configure, takeSnapshot } from "../dist/index.mjs";
 import { test } from "./utils/browser";
 
 test.override({ url: "/manual-snapshots" });
diff --git a/packages/vitest/test/newline-test-names.test.ts b/packages/vitest/test/newline-test-names.test.ts
index d1bc4e88..432ce50d 100644
--- a/packages/vitest/test/newline-test-names.test.ts
+++ b/packages/vitest/test/newline-test-names.test.ts
@@ -1,6 +1,6 @@
 import { describe } from "vitest";
 
-import { configure, takeSnapshot } from "../dist";
+import { configure, takeSnapshot } from "../dist/index.mjs";
 import { test } from "./utils/browser";
 
 describe(`
diff --git a/packages/vitest/test/options.test.ts b/packages/vitest/test/options.test.ts
index 7ed0e146..3de09d98 100644
--- a/packages/vitest/test/options.test.ts
+++ b/packages/vitest/test/options.test.ts
@@ -1,4 +1,4 @@
-import { configure } from "../dist";
+import { configure } from "../dist/index.mjs";
 import { test } from "./utils/browser";
 
 test("delay", async ({ goTo }) => {
diff --git a/packages/vitest/test/snapshot-names.test.ts b/packages/vitest/test/snapshot-names.test.ts
index 95aa7aa4..61efb7c1 100644
--- a/packages/vitest/test/snapshot-names.test.ts
+++ b/packages/vitest/test/snapshot-names.test.ts
@@ -1,6 +1,6 @@
 import { describe, beforeEach } from "vitest";
 
-import { configure, takeSnapshot } from "../dist";
+import { configure, takeSnapshot } from "../dist/index.mjs";
 import { test } from "./utils/browser";
 
 configure({ disableAutoSnapshot: true });
diff --git a/packages/vitest/test/utils/node.ts b/packages/vitest/test/utils/node.ts
index 34d2c333..215eba3f 100644
--- a/packages/vitest/test/utils/node.ts
+++ b/packages/vitest/test/utils/node.ts
@@ -14,7 +14,7 @@ import {
   createVitest,
   type InlineConfig,
   startVitest,
-  TestSequencer,
+  type TestSequencer,
   version as vitestVersion,
   type TestSpecification,
 } from "vitest/node";
diff --git a/packages/vitest/tsconfig.json b/packages/vitest/tsconfig.json
index 9e01ac63..762852e0 100644
--- a/packages/vitest/tsconfig.json
+++ b/packages/vitest/tsconfig.json
@@ -3,5 +3,12 @@
   "compilerOptions": {
     "stripInternal": true
   },
-  "include": ["src", "test", "vitest.config.unit.ts", "vitest.config.browser.ts"]
+  "include": [
+    "src",
+    "test",
+    "embedded.test.ts",
+    "vitest.config.unit.ts",
+    "vitest.config.browser.ts"
+  ],
+  "exclude": ["test/fixtures"]
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 390ba2c0..58752109 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -108,6 +108,9 @@ importers:
       tsdown:
         specifier: ^0.22.14
         version: 0.22.14(publint@0.3.24)(typescript@5.9.3)
+      typescript:
+        specifier: ^5.9.3
+        version: 5.9.3
 
   packages/playwright:
     dependencies:
@@ -151,6 +154,9 @@ importers:
       tsdown:
         specifier: ^0.22.14
         version: 0.22.14(publint@0.3.24)(typescript@5.9.3)
+      typescript:
+        specifier: ^5.9.3
+        version: 5.9.3
 
   packages/shared:
     dependencies:
@@ -189,8 +195,8 @@ importers:
         specifier: ^2.6.6
         version: 2.6.13
       mime:
-        specifier: ^3.0.0
-        version: 3.0.0
+        specifier: ^4.0.0
+        version: 4.1.0
       node-fetch:
         specifier: '2'
         version: 2.7.0
@@ -258,6 +264,9 @@ importers:
       tsdown:
         specifier: ^0.22.14
         version: 0.22.14(publint@0.3.24)(typescript@5.9.3)
+      typescript:
+        specifier: ^5.9.3
+        version: 5.9.3
       vitest:
         specifier: ^5.0.0
         version: 5.0.0(@types/node@22.20.1)(@vitest/browser-playwright@5.0.0)(@vitest/coverage-v8@5.0.0)(@vitest/ui@5.0.0)(msw@2.15.0(@types/node@22.20.1)(typescript@5.9.3))(vite@8.1.4(@types/node@22.20.1)(esbuild@0.27.7)(jiti@2.7.0)(terser@5.49.0)(yaml@2.9.0))
@@ -3002,9 +3011,9 @@ packages:
     engines: {node: '>=4'}
     hasBin: true
 
-  mime@3.0.0:
-    resolution: {integrity: sha512-jSCU7/VB1loIWBZe14aEYHU/+1UMEHoaO7qxCOVJOw9GgH72VAWppxNcjU+x9a2k3GSIBXNKxXQFqRvvZ7vr3A==}
-    engines: {node: '>=10.0.0'}
+  mime@4.1.0:
+    resolution: {integrity: sha512-X5ju04+cAzsojXKes0B/S4tcYtFAJ6tTMuSPBEn9CPGlrWr8Fiw7qYeLT0XyH80HSoAoqWCaz+MWKh22P7G1cw==}
+    engines: {node: '>=16'}
     hasBin: true
 
   mimic-fn@2.1.0:
@@ -7036,7 +7045,7 @@ snapshots:
 
   mime@1.6.0: {}
 
-  mime@3.0.0: {}
+  mime@4.1.0: {}
 
   mimic-fn@2.1.0: {}
 
diff --git a/tsconfig.json b/tsconfig.json
index 99487b6b..61ddf0b1 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,5 @@
 {
   "compilerOptions": {
-    "allowSyntheticDefaultImports": true,
     "paths": {
       "playwright-core/types/protocol": [
         "./packages/shared/node_modules/playwright-core/types/protocol.d.ts"
@@ -8,19 +7,15 @@
       "@chromatic-com/shared-e2e": ["./packages/shared/src/index.ts"],
       "@chromatic-com/shared-e2e/*": ["./packages/shared/src/*"]
     },
-    "emitDecoratorMetadata": true,
-    "esModuleInterop": true,
-    "experimentalDecorators": true,
-    "incremental": false,
     "isolatedModules": true,
-    "strictBindCallApply": true,
-    "jsx": "react",
     "lib": ["es2023", "dom", "dom.iterable"],
     "module": "preserve",
-    "moduleResolution": "bundler",
-    "noImplicitAny": true,
     "skipLibCheck": true,
-    "target": "es2023"
+    "target": "es2023",
+
+    // TODO: Enable "strict: true" and remove these:
+    "noImplicitAny": true,
+    "strictBindCallApply": true
   },
-  "include": ["packages/**/*.ts", "packages/**/*.tsx", "scripts/**/*.ts", "vitest.config.ts"]
+  "include": ["packages/**/*.ts", "scripts/**/*.ts", "vitest.config.ts"]
 }