diff --git a/src/io/conversion/manager.test.ts b/src/io/conversion/manager.test.ts
new file mode 100644
index 0000000..54a96cf
--- /dev/null
+++ b/src/io/conversion/manager.test.ts
@@ -0,0 +1,87 @@
+import { describe, it, expect } from "vitest";
+import { ConversionManager, ConversionTimeoutError } from "./manager";
+import type { ConversionRequest, ConversionResult, ModelConverter } from "./types";
+
+function createMockConverter(
+  delayMs: number,
+  result: ConversionResult,
+): ModelConverter {
+  return {
+    id: "mock",
+    sourceExts: [".test"],
+    targetExt: "glb",
+    getCacheKey: async () => "mock-cache-key",
+    convert: async () => {
+      await new Promise((resolve) => setTimeout(resolve, delayMs));
+      return result;
+    },
+  };
+}
+
+const successResult: ConversionResult = {
+  outputPath: "/out/mock.glb",
+  outputExt: "glb",
+  fromCache: false,
+  warnings: [],
+};
+
+describe("ConversionManager", () => {
+  it("converts a supported file", async () => {
+    const manager = new ConversionManager();
+    manager.registerConverter(createMockConverter(0, successResult));
+    const result = await manager.convert({
+      sourcePath: "/in/model.test",
+      sourceExt: ".test",
+      targetExt: "glb",
+    });
+    expect(result.outputPath).toBe("/out/mock.glb");
+  });
+
+  it("throws when no converter is registered", async () => {
+    const manager = new ConversionManager();
+    await expect(
+      manager.convert({
+        sourcePath: "/in/model.unknown",
+        sourceExt: ".unknown",
+        targetExt: "glb",
+      }),
+    ).rejects.toThrow("No converter registered");
+  });
+
+  it("times out a hanging conversion", async () => {
+    const manager = new ConversionManager();
+    manager.registerConverter(createMockConverter(10_000, successResult));
+    await expect(
+      manager.convert({
+        sourcePath: "/in/model.test",
+        sourceExt: ".test",
+        targetExt: "glb",
+        timeoutMs: 50,
+      }),
+    ).rejects.toThrow(ConversionTimeoutError);
+  });
+
+  it("deduplicates concurrent conversions for the same source", async () => {
+    const manager = new ConversionManager();
+    let calls = 0;
+    manager.registerConverter({
+      id: "mock",
+      sourceExts: [".test"],
+      targetExt: "glb",
+      getCacheKey: async () => "key",
+      convert: async () => {
+        calls++;
+        await new Promise((resolve) => setTimeout(resolve, 20));
+        return successResult;
+      },
+    });
+    const req: ConversionRequest = {
+      sourcePath: "/in/model.test",
+      sourceExt: ".test",
+      targetExt: "glb",
+    };
+    const [a, b] = await Promise.all([manager.convert(req), manager.convert(req)]);
+    expect(a).toBe(b);
+    expect(calls).toBe(1);
+  });
+});
diff --git a/src/utils/escape-html.test.ts b/src/utils/escape-html.test.ts
new file mode 100644
index 0000000..f22b3ae
--- /dev/null
+++ b/src/utils/escape-html.test.ts
@@ -0,0 +1,22 @@
+import { describe, it, expect } from "vitest";
+import { escapeHtml } from "./escape-html";
+
+describe("escapeHtml", () => {
+  it("escapes HTML special characters", () => {
+    expect(escapeHtml("<script>alert('xss')</script>")).toBe(
+      "&lt;script&gt;alert(&#39;xss&#39;)&lt;/script&gt;",
+    );
+  });
+
+  it("escapes double quotes", () => {
+    expect(escapeHtml('value="test"')).toBe("value=&quot;test&quot;");
+  });
+
+  it("leaves plain text unchanged", () => {
+    expect(escapeHtml("hello world")).toBe("hello world");
+  });
+
+  it("handles empty strings", () => {
+    expect(escapeHtml("")).toBe("");
+  });
+});
diff --git a/src/view/workbench/remote-draft-normalizer.ts b/src/view/workbench/remote-draft-normalizer.ts
new file mode 100644
index 0000000..e9f6081
--- /dev/null
+++ b/src/view/workbench/remote-draft-normalizer.ts
@@ -0,0 +1,53 @@
+import { escapeHtml } from "../../utils/escape-html";
+import type { RemoteDraftResult } from "../../domain/models";
+
+const MAX_REMOTE_DRAFT_FIELD_LENGTH = 8000;
+
+function sanitizeRemoteDraftString(value: string): string {
+  const trimmed = value.trim();
+  if (trimmed.length > MAX_REMOTE_DRAFT_FIELD_LENGTH) {
+    return escapeHtml(trimmed.slice(0, MAX_REMOTE_DRAFT_FIELD_LENGTH)) + "…";
+  }
+  return escapeHtml(trimmed);
+}
+
+export function normalizeRemoteDraftResult(value: unknown): RemoteDraftResult | null {
+  if (!value || typeof value !== "object") {
+    return null;
+  }
+  const record = value as Record<string, unknown>;
+  const summaryRaw = typeof record.summary === "string" ? record.summary.trim() : "";
+  const summary = sanitizeRemoteDraftString(summaryRaw);
+  if (!summary) {
+    return null;
+  }
+  const sections = Array.isArray(record.sections)
+    ? record.sections.flatMap((section) => {
+        if (!section || typeof section !== "object") return [];
+        const sectionRecord = section as Record<string, unknown>;
+        const headingRaw = typeof sectionRecord.heading === "string" ? sectionRecord.heading.trim() : "";
+        const bodyRaw = typeof sectionRecord.body === "string" ? sectionRecord.body.trim() : "";
+        const heading = sanitizeRemoteDraftString(headingRaw);
+        const body = sanitizeRemoteDraftString(bodyRaw);
+        return heading && body ? [{ heading, body }] : [];
+      })
+    : undefined;
+  const suggestedTags = Array.isArray(record.suggestedTags)
+    ? record.suggestedTags
+        .filter((tag): tag is string => typeof tag === "string" && tag.trim().length > 0)
+        .map((tag) => sanitizeRemoteDraftString(tag))
+    : undefined;
+  const warnings = Array.isArray(record.warnings)
+    ? record.warnings
+        .filter((warning): warning is string => typeof warning === "string" && warning.trim().length > 0)
+        .map((warning) => sanitizeRemoteDraftString(warning))
+    : undefined;
+  return {
+    title: typeof record.title === "string" ? sanitizeRemoteDraftString(record.title) : undefined,
+    summary,
+    sections,
+    suggestedTags,
+    warnings,
+    model: typeof record.model === "string" ? sanitizeRemoteDraftString(record.model) : undefined,
+  };
+}
diff --git a/src/view/workbench/remote-draft.test.ts b/src/view/workbench/remote-draft.test.ts
new file mode 100644
index 0000000..efbdc5a
--- /dev/null
+++ b/src/view/workbench/remote-draft.test.ts
@@ -0,0 +1,33 @@
+import { describe, it, expect } from "vitest";
+import { normalizeRemoteDraftResult } from "./remote-draft-normalizer";
+
+describe("normalizeRemoteDraftResult", () => {
+  it("returns null for missing summary", () => {
+    expect(normalizeRemoteDraftResult({ title: "test" })).toBeNull();
+  });
+
+  it("sanitizes HTML in remote draft fields", () => {
+    const result = normalizeRemoteDraftResult({
+      title: "<img src=x onerror=alert(1)>",
+      summary: "Summary with <script>bad()</script>",
+      sections: [{ heading: "<b>heading</b>", body: "<p>body</p>" }],
+      suggestedTags: ["<tag>"],
+      warnings: ["<alert>"],
+      model: "<model>",
+    });
+    expect(result).not.toBeNull();
+    expect(result?.title).toBe("&lt;img src=x onerror=alert(1)&gt;");
+    expect(result?.summary).toBe("Summary with &lt;script&gt;bad()&lt;/script&gt;");
+    expect(result?.sections?.[0].heading).toBe("&lt;b&gt;heading&lt;/b&gt;");
+    expect(result?.sections?.[0].body).toBe("&lt;p&gt;body&lt;/p&gt;");
+    expect(result?.suggestedTags?.[0]).toBe("&lt;tag&gt;");
+    expect(result?.warnings?.[0]).toBe("&lt;alert&gt;");
+    expect(result?.model).toBe("&lt;model&gt;");
+  });
+
+  it("caps overly long fields", () => {
+    const long = "a".repeat(10_000);
+    const result = normalizeRemoteDraftResult({ summary: long });
+    expect(result?.summary.length).toBeLessThanOrEqual(8001);
+  });
+});
diff --git a/src/view/workbench/remote-draft.ts b/src/view/workbench/remote-draft.ts
index 0fe8755..56a2dac 100644
--- a/src/view/workbench/remote-draft.ts
+++ b/src/view/workbench/remote-draft.ts
@@ -1,6 +1,6 @@
 import { requestUrl } from "obsidian";
 
-import { escapeHtml } from "../../utils/escape-html";
+import { normalizeRemoteDraftResult } from "./remote-draft-normalizer";
 import type {
   AnalysisDraftingInput,
   PluginSettings,
@@ -123,57 +123,6 @@ export function createRemoteDraftDecision(
   };
 }
 
-const MAX_REMOTE_DRAFT_FIELD_LENGTH = 8000;
-
-function sanitizeRemoteDraftString(value: string): string {
-  const trimmed = value.trim();
-  if (trimmed.length > MAX_REMOTE_DRAFT_FIELD_LENGTH) {
-    return escapeHtml(trimmed.slice(0, MAX_REMOTE_DRAFT_FIELD_LENGTH)) + "…";
-  }
-  return escapeHtml(trimmed);
-}
-
-function normalizeRemoteDraftResult(value: unknown): RemoteDraftResult | null {
-  if (!value || typeof value !== "object") {
-    return null;
-  }
-  const record = value as Record<string, unknown>;
-  const summaryRaw = typeof record.summary === "string" ? record.summary.trim() : "";
-  const summary = sanitizeRemoteDraftString(summaryRaw);
-  if (!summary) {
-    return null;
-  }
-  const sections = Array.isArray(record.sections)
-    ? record.sections.flatMap((section) => {
-        if (!section || typeof section !== "object") return [];
-        const sectionRecord = section as Record<string, unknown>;
-        const headingRaw = typeof sectionRecord.heading === "string" ? sectionRecord.heading.trim() : "";
-        const bodyRaw = typeof sectionRecord.body === "string" ? sectionRecord.body.trim() : "";
-        const heading = sanitizeRemoteDraftString(headingRaw);
-        const body = sanitizeRemoteDraftString(bodyRaw);
-        return heading && body ? [{ heading, body }] : [];
-      })
-    : undefined;
-  const suggestedTags = Array.isArray(record.suggestedTags)
-    ? record.suggestedTags
-        .filter((tag): tag is string => typeof tag === "string" && tag.trim().length > 0)
-        .map((tag) => sanitizeRemoteDraftString(tag))
-    : undefined;
-  const warnings = Array.isArray(record.warnings)
-    ? record.warnings
-        .filter((warning): warning is string => typeof warning === "string" && warning.trim().length > 0)
-        .map((warning) => sanitizeRemoteDraftString(warning))
-    : undefined;
-  return {
-    title: typeof record.title === "string" ? sanitizeRemoteDraftString(record.title) : undefined,
-    summary,
-    sections,
-    suggestedTags,
-    warnings,
-    model: typeof record.model === "string" ? sanitizeRemoteDraftString(record.model) : undefined,
-  };
-}
-
 export async function requestRemoteDraft(decision: RemoteDraftDecision): Promise<RemoteDraftResult | null> {
   if (!decision.enabled || !decision.endpoint || !decision.request) {
     return null;
diff --git a/vitest.config.ts b/vitest.config.ts
new file mode 100644
index 0000000..c1d4aee
--- /dev/null
+++ b/vitest.config.ts
@@ -0,0 +1,15 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    globals: false,
+    environment: "node",
+    include: ["src/**/*.test.ts"],
+    coverage: {
+      provider: "v8",
+      reporter: ["text", "html"],
+      include: ["src/**/*.ts"],
+      exclude: ["src/**/*.test.ts", "src/**/*.d.ts"],
+    },
+  },
+});