diff --git a/src/components/PageHead.test.ts b/src/components/PageHead.test.ts
new file mode 100644
index 0000000..ef211c3
--- /dev/null
+++ b/src/components/PageHead.test.ts
@@ -0,0 +1,157 @@
+/**
+ * Unit tests for `PageHead` site-aware metadata derivation (task 02).
+ *
+ * `resolvePageHeadMeta` is a pure function over (props, site, pathname), so
+ * these tests mirror the acceptance matrix without a DOM / SolidJS router.
+ * The render layer (`PageHead` component) is a thin wrapper over this function.
+ */
+import { describe, it, expect } from "bun:test";
+import {
+  resolvePageHeadMeta,
+  type PageHeadProps
+} from "~/components/page-head-meta";
+import { SITE_CONFIG, type SiteId } from "~/lib/site-context";
+
+const BASE_PROPS: PageHeadProps = {
+  title: "Blog",
+  description: "Technical blog posts about web development."
+};
+
+describe("resolvePageHeadMeta — title suffix per site", () => {
+  const cases: Array<{ id: SiteId; suffix: string }> = [
+    { id: "main", suffix: " | Michael Freno" },
+    { id: "nessa", suffix: " | Nessa" },
+    { id: "lineage", suffix: " | Life and Lineage" },
+    { id: "gaze", suffix: " | Gaze" },
+    { id: "inputhalo", suffix: " | InputHalo" }
+  ];
+
+  for (const { id, suffix } of cases) {
+    it(`${id} → title is "${BASE_PROPS.title}${suffix}"`, () => {
+      const meta = resolvePageHeadMeta(
+        BASE_PROPS,
+        SITE_CONFIG[id],
+        "/blog"
+      );
+      expect(meta.title).toBe(`${BASE_PROPS.title}${suffix}`);
+    });
+  }
+
+  it("main produces 'Home | Michael Freno' for the homepage", () => {
+    const meta = resolvePageHeadMeta(
+      { title: "Home" },
+      SITE_CONFIG.main,
+      "/"
+    );
+    expect(meta.title).toBe("Home | Michael Freno");
+  });
+});
+
+describe("resolvePageHeadMeta — canonical URL derivation", () => {
+  it("main → canonical starts with https://freno.me", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.main, "/");
+    expect(meta.canonical).toBe("https://freno.me/");
+  });
+
+  it("main blog → https://freno.me/blog", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.main, "/blog");
+    expect(meta.canonical).toBe("https://freno.me/blog");
+  });
+
+  it("nessa → canonical starts with https://nessa.freno.me", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.nessa, "/");
+    expect(meta.canonical).toBe("https://nessa.freno.me/");
+  });
+
+  it("nessa /contact → https://nessa.freno.me/contact", () => {
+    const meta = resolvePageHeadMeta(
+      BASE_PROPS,
+      SITE_CONFIG.nessa,
+      "/contact"
+    );
+    expect(meta.canonical).toBe("https://nessa.freno.me/contact");
+  });
+
+  it("lineage → canonical starts with https://lineage.freno.me", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.lineage, "/");
+    expect(meta.canonical.startsWith("https://lineage.freno.me")).toBe(true);
+  });
+
+  it("gaze → canonical starts with https://gaze.freno.me", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.gaze, "/");
+    expect(meta.canonical.startsWith("https://gaze.freno.me")).toBe(true);
+  });
+
+  it("inputhalo → canonical starts with https://inputhalo.freno.me", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.inputhalo, "/");
+    expect(meta.canonical.startsWith("https://inputhalo.freno.me")).toBe(true);
+  });
+
+  it("preserves the full pathname including nested segments + search is NOT included", () => {
+    // useLocation().pathname excludes the query string; canonical should too.
+    const meta = resolvePageHeadMeta(
+      BASE_PROPS,
+      SITE_CONFIG.main,
+      "/blog/my-post"
+    );
+    expect(meta.canonical).toBe("https://freno.me/blog/my-post");
+  });
+
+  it("explicit `canonical` prop overrides auto-derivation", () => {
+    const meta = resolvePageHeadMeta(
+      { ...BASE_PROPS, canonical: "https://example.com/override" },
+      SITE_CONFIG.nessa,
+      "/contact"
+    );
+    expect(meta.canonical).toBe("https://example.com/override");
+  });
+});
+
+describe("resolvePageHeadMeta — OpenGraph fallbacks", () => {
+  it("ogImage defaults to the site's ogDefaultImage when not provided", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.nessa, "/");
+    expect(meta.ogImage).toBe(SITE_CONFIG.nessa.ogDefaultImage);
+  });
+
+  it("explicit ogImage overrides the site default", () => {
+    const meta = resolvePageHeadMeta(
+      { ...BASE_PROPS, ogImage: "https://cdn/custom.png" },
+      SITE_CONFIG.main,
+      "/"
+    );
+    expect(meta.ogImage).toBe("https://cdn/custom.png");
+  });
+
+  it("ogTitle falls back to the base title (no suffix)", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.main, "/");
+    expect(meta.ogTitle).toBe("Blog");
+  });
+
+  it("explicit ogTitle overrides the title fallback", () => {
+    const meta = resolvePageHeadMeta(
+      { ...BASE_PROPS, ogTitle: "Custom OG Title" },
+      SITE_CONFIG.main,
+      "/"
+    );
+    expect(meta.ogTitle).toBe("Custom OG Title");
+  });
+
+  it("ogDescription falls back to description", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.main, "/");
+    expect(meta.ogDescription).toBe(BASE_PROPS.description);
+  });
+
+  it("explicit ogDescription overrides the description fallback", () => {
+    const meta = resolvePageHeadMeta(
+      { ...BASE_PROPS, ogDescription: "Custom OG desc" },
+      SITE_CONFIG.main,
+      "/"
+    );
+    expect(meta.ogDescription).toBe("Custom OG desc");
+  });
+
+  it("description is passed through unchanged", () => {
+    const meta = resolvePageHeadMeta(BASE_PROPS, SITE_CONFIG.main, "/");
+    expect(meta.description).toBe(BASE_PROPS.description);
+  });
+});
diff --git a/src/components/PageHead.tsx b/src/components/PageHead.tsx
index 06b85bf..ba4446d 100644
--- a/src/components/PageHead.tsx
+++ b/src/components/PageHead.tsx
@@ -1,17 +1,31 @@
 import { Title, Meta, Link } from "@solidjs/meta";
+import { useLocation } from "@solidjs/router";
+import { useSite } from "~/context/SiteContext";
+import {
+  resolvePageHeadMeta,
+  type PageHeadProps
+} from "~/components/page-head-meta";
 
-export interface PageHeadProps {
-  title: string;
-  description?: string;
-  ogImage?: string;
-  ogTitle?: string;
-  ogDescription?: string;
-  canonical?: string;
-}
+// Re-export the pure types + resolver so existing imports
+// (`import { PageHead } from "~/components/PageHead"`) plus any consumer that
+// wants the meta helper resolve from a single module path.
+export {
+  resolvePageHeadMeta,
+  type PageHeadProps,
+  type ResolvedPageHeadMeta
+} from "~/components/page-head-meta";
 
 /**
  * PageHead component for consistent page metadata across the application.
- * Automatically appends " | Michael Freno" to the title.
+ *
+ * Site-aware (task 02): reads `useSite()` for the per-site title suffix,
+ * canonical domain, and default OpenGraph image, so the same component
+ * renders `" | Michael Freno"` / `" | Nessa"` / … depending on the active
+ * subdomain. Canonical URLs are auto-derived from the site domain + the
+ * current router pathname unless an explicit `canonical` override is given.
+ *
+ * The actual derivation lives in the pure `resolvePageHeadMeta` helper (see
+ * `~/components/page-head-meta.ts`) so it can be unit-tested without a DOM.
  *
  * @example
  * ```tsx
@@ -23,27 +37,25 @@ export interface PageHeadProps {
  * ```
  */
 export default function PageHead(props: PageHeadProps) {
-  const fullTitle = () => `${props.title} | Michael Freno`;
+  const site = useSite();
+  const location = useLocation();
+
+  const meta = () => resolvePageHeadMeta(props, site(), location.pathname);
 
   return (
     <>
-      <Title>{fullTitle()}</Title>
-      {props.description && (
-        <Meta name="description" content={props.description} />
+      <Title>{meta().title}</Title>
+      {meta().description && (
+        <Meta name="description" content={meta().description} />
       )}
-      {props.canonical && <Link rel="canonical" href={props.canonical} />}
+      <Link rel="canonical" href={meta().canonical} />
 
       {/* Open Graph / Social Media Tags */}
-      {(props.ogTitle || props.title) && (
-        <Meta property="og:title" content={props.ogTitle || props.title} />
+      <Meta property="og:title" content={meta().ogTitle} />
+      {meta().ogDescription && (
+        <Meta property="og:description" content={meta().ogDescription} />
       )}
-      {(props.ogDescription || props.description) && (
-        <Meta
-          property="og:description"
-          content={props.ogDescription || props.description}
-        />
-      )}
-      {props.ogImage && <Meta property="og:image" content={props.ogImage} />}
+      <Meta property="og:image" content={meta().ogImage} />
     </>
   );
 }
diff --git a/src/components/page-head-meta.ts b/src/components/page-head-meta.ts
new file mode 100644
index 0000000..769027b
--- /dev/null
+++ b/src/components/page-head-meta.ts
@@ -0,0 +1,70 @@
+/**
+ * Pure metadata derivation for `PageHead` (task 02).
+ *
+ * Intentionally imports NOTHING from solid-js / @solidjs/router / @solidjs/meta
+ * so it can be unit-tested in `bun:test` without spinning up the SolidJS
+ * router + MetaProvider + DOM (which this repo does not configure). The
+ * `PageHead` component is a thin render layer over this function.
+ *
+ * Rules:
+ *  - `title` → `props.title + site.titleSuffix`
+ *  - `canonical` → explicit `props.canonical` override wins; otherwise
+ *    `https://${site.domain}${pathname}`. The pathname is the *browser* path
+ *    (from `useLocation`), which is correct because vercel.json host rewrites
+ *    target internal route prefixes (`/nessa`, `/lineage`, …) while leaving
+ *    the public URL intact — so `nessa.freno.me/contact` reports pathname
+ *    `/contact`, and the canonical is `https://nessa.freno.me/contact`.
+ *  - `ogImage` → explicit `props.ogImage` wins; otherwise `site.ogDefaultImage`.
+ *  - `ogTitle` / `ogDescription` → explicit override wins; otherwise fall
+ *    back to the base title (no suffix) / description (existing behavior).
+ */
+import type { Site } from "~/lib/site-context";
+
+export interface PageHeadProps {
+  title: string;
+  description?: string;
+  ogImage?: string;
+  ogTitle?: string;
+  ogDescription?: string;
+  canonical?: string;
+}
+
+/**
+ * Fully-resolved metadata computed by {@link resolvePageHeadMeta}. `PageHead`
+ * renders these verbatim. Kept as an exported type so call sites / tests can
+ * assert against the exact values without a DOM render.
+ */
+export interface ResolvedPageHeadMeta {
+  /** Page title with the active site's `titleSuffix` appended. */
+  title: string;
+  description?: string;
+  /** Canonical absolute URL for the current route. */
+  canonical: string;
+  /** OpenGraph title (falls back to the page title without suffix). */
+  ogTitle: string;
+  /** OpenGraph description (falls back to `description`). */
+  ogDescription?: string;
+  /** OpenGraph image (defaults to the site's `ogDefaultImage`). */
+  ogImage: string;
+}
+
+export function resolvePageHeadMeta(
+  props: PageHeadProps,
+  site: Site,
+  pathname: string
+): ResolvedPageHeadMeta {
+  const title = `${props.title}${site.titleSuffix}`;
+  const canonical = props.canonical ?? `https://${site.domain}${pathname}`;
+  const ogTitle = props.ogTitle ?? props.title;
+  const ogDescription = props.ogDescription ?? props.description;
+  const ogImage = props.ogImage ?? site.ogDefaultImage;
+
+  return {
+    title,
+    description: props.description,
+    canonical,
+    ogTitle,
+    ogDescription,
+    ogImage
+  };
+}