diff --git a/.fallowrc.jsonc b/.fallowrc.jsonc
index c94e4cb47b..f4d3feabc5 100644
--- a/.fallowrc.jsonc
+++ b/.fallowrc.jsonc
@@ -18,7 +18,7 @@
     "packages/producer/src/perf-gate.ts",
     "packages/producer/src/runtime-conformance.ts",
     "packages/producer/src/benchmark.ts",
-    "packages/producer/scripts/generate-font-data.ts",
+    "packages/core/scripts/generate-font-data.ts",
     "packages/producer/we-render.mjs",
     "packages/producer/scripts/validate-fast-video.ts",
     "packages/cli/scripts/generate-font-data.ts",
@@ -494,6 +494,16 @@
       // new package makes fallow see it as a fresh finding; the underlying clone
       // predates this refactor.
       "packages/parsers/src/hfIds.ts",
+      // Font pipeline: pre-existing duplication moved from packages/producer/src/services/
+      // and producer/scripts/ to core/src/fonts/ and core/scripts/ (the generator mirrors
+      // CANONICAL_FONTS; the tests share arrange/act scaffolds).
+      "packages/core/scripts/generate-font-data.ts",
+      "packages/core/src/fonts/deterministicFonts-aliasSupplement.test.ts",
+      "packages/core/src/fonts/deterministicFonts-authoredResources.test.ts",
+      "packages/core/src/fonts/deterministicFonts-failClosed.test.ts",
+      "packages/core/src/fonts/deterministicFonts-googleSubsets.test.ts",
+      "packages/core/src/fonts/deterministicFonts-retries.test.ts",
+      "packages/core/src/fonts/fontCompression.test.ts",
       // Parser test files: parallel arrange/act/assert test cases — pre-existing
       // duplication moved from packages/core/src/parsers/.
       "packages/parsers/src/gsapParser.test.ts",
@@ -733,6 +743,9 @@
     // complexity pre-dates the computed-timeline work. Exempted at file level
     // rather than refactored as scope creep.
     "ignore": [
+      // generate-font-data.ts: the build-time font data generator moved from producer/scripts;
+      // its CRAP score is coverage-driven (a build script no unit test runs).
+      "packages/core/scripts/generate-font-data.ts",
       // audio-fx-runtime-entry.ts: the browser-side IIFE entry for the offline FX
       // render. It runs only inside the headless page the engine drives, so unit
       // coverage cannot reach it and its CRAP score is coverage-driven rather
diff --git a/.gitignore b/.gitignore
index a400a99105..0a72e3b30c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -75,7 +75,7 @@ tmp/
 packages/core/src/generated/*
 !packages/core/src/generated/position-edits-render-inline.ts
 !packages/core/src/generated/position-edits-render-inline.test.ts
-packages/producer/src/services/fontData.generated.ts
+packages/core/src/fonts/fontData.generated.ts
 
 # Plan documents (working artifacts, not committed)
 docs/plans/
diff --git a/Dockerfile.test b/Dockerfile.test
index e85da3f21e..78f14544c6 100644
--- a/Dockerfile.test
+++ b/Dockerfile.test
@@ -122,9 +122,6 @@ RUN bun run --filter @hyperframes/core build:hyperframes-runtime:modular
 COPY packages/engine/ packages/engine/
 COPY packages/producer/ packages/producer/
 
-# Generate embedded font data (deterministicFonts.ts imports this at runtime)
-RUN cd packages/producer && bunx tsx scripts/generate-font-data.ts
-
 WORKDIR /app/packages/producer
 
 # Skip fixtures tagged `transparency` (Chrome alpha-channel PSNR quirks not
diff --git a/bun.lock b/bun.lock
index a8d7af76cf..4fccbde3cc 100644
--- a/bun.lock
+++ b/bun.lock
@@ -24,7 +24,7 @@
     },
     "packages/aws-lambda": {
       "name": "@hyperframes/aws-lambda",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@aws-sdk/client-s3": "^3.700.0",
         "@aws-sdk/client-sfn": "^3.700.0",
@@ -57,7 +57,7 @@
     },
     "packages/cli": {
       "name": "@hyperframes/cli",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "bin": {
         "hyperframes": "./bin/hyperframes.mjs",
         "hyperframes-localize-fonts": "./bin/hyperframes-localize-fonts.mjs",
@@ -109,7 +109,7 @@
     },
     "packages/core": {
       "name": "@hyperframes/core",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@chenglou/pretext": "^0.0.5",
         "@hyperframes/lint": "workspace:*",
@@ -118,8 +118,27 @@
         "bpm-detective": "^2.0.5",
         "linkedom": "^0.18.12",
         "postcss": "^8.5.8",
+        "wawoff2": "^2.0.1",
       },
       "devDependencies": {
+        "@fontsource/archivo-black": "^5.2.8",
+        "@fontsource/eb-garamond": "^5.2.7",
+        "@fontsource/ibm-plex-mono": "^5.2.7",
+        "@fontsource/inter": "^5.2.8",
+        "@fontsource/jetbrains-mono": "^5.2.8",
+        "@fontsource/lato": "^5.2.7",
+        "@fontsource/league-gothic": "^5.2.8",
+        "@fontsource/montserrat": "^5.2.8",
+        "@fontsource/noto-sans-jp": "^5.2.9",
+        "@fontsource/nunito": "^5.2.7",
+        "@fontsource/open-sans": "^5.2.7",
+        "@fontsource/oswald": "^5.2.8",
+        "@fontsource/outfit": "^5.2.8",
+        "@fontsource/playfair-display": "^5.2.8",
+        "@fontsource/poppins": "^5.2.7",
+        "@fontsource/roboto": "^5.2.10",
+        "@fontsource/source-code-pro": "^5.2.7",
+        "@fontsource/space-mono": "^5.2.9",
         "@types/jsdom": "^28.0.0",
         "@types/node": "^25.0.10",
         "@vitest/coverage-v8": "^4.1.11",
@@ -135,7 +154,7 @@
     },
     "packages/engine": {
       "name": "@hyperframes/engine",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@hono/node-server": "^2.0.5",
         "@hyperframes/core": "workspace:^",
@@ -154,7 +173,7 @@
     },
     "packages/gcp-cloud-run": {
       "name": "@hyperframes/gcp-cloud-run",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@google-cloud/storage": "^7.14.0",
         "@google-cloud/workflows": "^4.2.0",
@@ -175,7 +194,7 @@
     },
     "packages/lint": {
       "name": "@hyperframes/lint",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@hyperframes/parsers": "workspace:*",
         "acorn": "^8.17.0",
@@ -195,7 +214,7 @@
     },
     "packages/parsers": {
       "name": "@hyperframes/parsers",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@babel/parser": "^7.27.0",
         "acorn": "^8.17.0",
@@ -215,7 +234,7 @@
     },
     "packages/player": {
       "name": "@hyperframes/player",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@hyperframes/core": "workspace:*",
       },
@@ -230,19 +249,8 @@
     },
     "packages/producer": {
       "name": "@hyperframes/producer",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
-        "@fontsource/archivo-black": "^5.2.8",
-        "@fontsource/eb-garamond": "^5.2.7",
-        "@fontsource/ibm-plex-mono": "^5.2.7",
-        "@fontsource/inter": "^5.2.8",
-        "@fontsource/jetbrains-mono": "^5.2.8",
-        "@fontsource/league-gothic": "^5.2.8",
-        "@fontsource/montserrat": "^5.2.8",
-        "@fontsource/nunito": "^5.2.7",
-        "@fontsource/oswald": "^5.2.8",
-        "@fontsource/outfit": "^5.2.8",
-        "@fontsource/space-mono": "^5.2.9",
         "@hono/node-server": "^2.0.5",
         "@hyperframes/core": "workspace:^",
         "@hyperframes/engine": "workspace:^",
@@ -254,16 +262,8 @@
         "postcss": "^8.4.0",
         "puppeteer": "^25.2.1",
         "puppeteer-core": "^25.2.1",
-        "wawoff2": "^2.0.1",
       },
       "devDependencies": {
-        "@fontsource/lato": "^5.2.7",
-        "@fontsource/noto-sans-jp": "^5.2.9",
-        "@fontsource/open-sans": "^5.2.7",
-        "@fontsource/playfair-display": "^5.2.8",
-        "@fontsource/poppins": "^5.2.7",
-        "@fontsource/roboto": "^5.2.10",
-        "@fontsource/source-code-pro": "^5.2.7",
         "@hyperframes/aws-lambda": "workspace:*",
         "@types/node": "^25.0.10",
         "@webgpu/types": "^0.1.69",
@@ -275,7 +275,7 @@
     },
     "packages/sdk": {
       "name": "@hyperframes/sdk",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@hyperframes/core": "workspace:*",
         "@hyperframes/parsers": "workspace:*",
@@ -305,7 +305,7 @@
     },
     "packages/shader-transitions": {
       "name": "@hyperframes/shader-transitions",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "html2canvas": "^1.4.1",
       },
@@ -317,7 +317,7 @@
     },
     "packages/studio": {
       "name": "@hyperframes/studio",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@base-ui/react": "1.7.0",
         "@codemirror/autocomplete": "^6.20.1",
@@ -370,7 +370,7 @@
     },
     "packages/studio-server": {
       "name": "@hyperframes/studio-server",
-      "version": "0.8.119",
+      "version": "0.8.126",
       "dependencies": {
         "@hyperframes/core": "workspace:*",
         "@hyperframes/parsers": "workspace:*",
diff --git a/packages/aws-lambda/scripts/_handlerBanner.ts b/packages/aws-lambda/scripts/_handlerBanner.ts
index 04c9ea9d58..1d2c915273 100644
--- a/packages/aws-lambda/scripts/_handlerBanner.ts
+++ b/packages/aws-lambda/scripts/_handlerBanner.ts
@@ -6,7 +6,7 @@
  * assume all three exist at module scope:
  *   - postcss et al. call top-level `require(...)`
  *   - wawoff2's emscripten build (pulled in unconditionally via
- *     producer → fontCompression) reads `__dirname` at module scope
+ *     producer → core fonts/fontCompression) reads `__dirname` at module scope
  * Without the shims the handler throws "Dynamic require of <X> is not
  * supported" / "__dirname is not defined in ES module scope" at import time,
  * before it can run — which is exactly how a freshly deployed stack crashed
diff --git a/packages/cli/scripts/build-fonts.mjs b/packages/cli/scripts/build-fonts.mjs
index 6cf2f50dc3..f1a39e738a 100644
--- a/packages/cli/scripts/build-fonts.mjs
+++ b/packages/cli/scripts/build-fonts.mjs
@@ -2,13 +2,13 @@
 import { existsSync } from "node:fs";
 import { execSync } from "node:child_process";
 
-const target = "../producer/src/services/fontData.generated.ts";
+const target = "../core/src/fonts/fontData.generated.ts";
 
 if (existsSync(target)) {
   console.log("[build:fonts] skipped — fontData.generated.ts already exists");
   process.exit(0);
 }
 
-execSync("cd ../producer && tsx scripts/generate-font-data.ts", {
+execSync("cd ../core && tsx scripts/generate-font-data.ts", {
   stdio: "inherit",
 });
diff --git a/packages/cli/src/server/studioServer.ts b/packages/cli/src/server/studioServer.ts
index e1acf8f2ec..0c65c6b41b 100644
--- a/packages/cli/src/server/studioServer.ts
+++ b/packages/cli/src/server/studioServer.ts
@@ -499,8 +499,7 @@ export function createStudioServer(options: StudioServerOptions): StudioServer {
     },
 
     async transformPreviewHtml({ html, project }) {
-      const { injectDeterministicFontFaces } =
-        await import("../../../producer/src/services/deterministicFonts.js");
+      const { injectDeterministicFontFaces } = await import("@hyperframes/core/fonts/embed");
       const { prepareAnimatedGifInputs } =
         await import("../../../producer/src/services/animatedGifPrep.js");
       const { downloadToTemp, writeUrlDownloadTelemetry } =
diff --git a/packages/core/package-subpaths.json b/packages/core/package-subpaths.json
index eead54ea7c..9f6200942a 100644
--- a/packages/core/package-subpaths.json
+++ b/packages/core/package-subpaths.json
@@ -482,6 +482,18 @@
       "types": "./dist/fonts/systemFontLocator.d.ts",
       "environments": ["bun", "node"]
     },
+    "./fonts/embed": {
+      "source": "./src/fonts/deterministicFonts.ts",
+      "runtime": "./dist/fonts/deterministicFonts.js",
+      "types": "./dist/fonts/deterministicFonts.d.ts",
+      "environments": ["bun", "node"]
+    },
+    "./fonts/embedded-data": {
+      "source": "./src/fonts/fontData.generated.ts",
+      "runtime": "./dist/fonts/fontData.generated.js",
+      "types": "./dist/fonts/fontData.generated.d.ts",
+      "environments": ["bun", "node"]
+    },
     "./figma": {
       "source": "./src/figma/index.ts",
       "runtime": "./dist/figma/index.js",
diff --git a/packages/core/package.json b/packages/core/package.json
index e6f41541f1..73d6bf3b13 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -491,6 +491,18 @@
       "import": "./src/fonts/systemFontLocator.ts",
       "types": "./src/fonts/systemFontLocator.ts"
     },
+    "./fonts/embed": {
+      "bun": "./src/fonts/deterministicFonts.ts",
+      "node": "./dist/fonts/deterministicFonts.js",
+      "import": "./src/fonts/deterministicFonts.ts",
+      "types": "./src/fonts/deterministicFonts.ts"
+    },
+    "./fonts/embedded-data": {
+      "bun": "./src/fonts/fontData.generated.ts",
+      "node": "./dist/fonts/fontData.generated.js",
+      "import": "./src/fonts/fontData.generated.ts",
+      "types": "./src/fonts/fontData.generated.ts"
+    },
     "./figma": {
       "bun": "./src/figma/index.ts",
       "node": "./dist/figma/index.js",
@@ -817,6 +829,14 @@
         "import": "./dist/fonts/systemFontLocator.js",
         "types": "./dist/fonts/systemFontLocator.d.ts"
       },
+      "./fonts/embed": {
+        "import": "./dist/fonts/deterministicFonts.js",
+        "types": "./dist/fonts/deterministicFonts.d.ts"
+      },
+      "./fonts/embedded-data": {
+        "import": "./dist/fonts/fontData.generated.js",
+        "types": "./dist/fonts/fontData.generated.d.ts"
+      },
       "./figma": {
         "import": "./dist/figma/index.js",
         "types": "./dist/figma/index.d.ts"
@@ -828,7 +848,8 @@
     "types": "./dist/index.d.ts"
   },
   "scripts": {
-    "build": "bun run build:hyperframes-runtime && bun run build:position-edits-render && bun run build:audio-fx-runtime && tsc && tsx scripts/rewrite-esm-extensions.ts",
+    "build": "bun run build:fonts && bun run build:hyperframes-runtime && bun run build:position-edits-render && bun run build:audio-fx-runtime && tsc && tsx scripts/rewrite-esm-extensions.ts",
+    "build:fonts": "node scripts/build-fonts.mjs",
     "test": "bun run check:position-edits-render && bun run build:audio-fx-runtime && vitest run",
     "test:watch": "vitest",
     "test:coverage": "vitest run --coverage",
@@ -861,9 +882,28 @@
     "@hyperframes/studio-server": "workspace:*",
     "bpm-detective": "^2.0.5",
     "linkedom": "^0.18.12",
-    "postcss": "^8.5.8"
+    "postcss": "^8.5.8",
+    "wawoff2": "^2.0.1"
   },
   "devDependencies": {
+    "@fontsource/archivo-black": "^5.2.8",
+    "@fontsource/eb-garamond": "^5.2.7",
+    "@fontsource/ibm-plex-mono": "^5.2.7",
+    "@fontsource/inter": "^5.2.8",
+    "@fontsource/jetbrains-mono": "^5.2.8",
+    "@fontsource/lato": "^5.2.7",
+    "@fontsource/league-gothic": "^5.2.8",
+    "@fontsource/montserrat": "^5.2.8",
+    "@fontsource/noto-sans-jp": "^5.2.9",
+    "@fontsource/nunito": "^5.2.7",
+    "@fontsource/open-sans": "^5.2.7",
+    "@fontsource/oswald": "^5.2.8",
+    "@fontsource/outfit": "^5.2.8",
+    "@fontsource/playfair-display": "^5.2.8",
+    "@fontsource/poppins": "^5.2.7",
+    "@fontsource/roboto": "^5.2.10",
+    "@fontsource/source-code-pro": "^5.2.7",
+    "@fontsource/space-mono": "^5.2.9",
     "@types/jsdom": "^28.0.0",
     "@types/node": "^25.0.10",
     "@vitest/coverage-v8": "^4.1.11",
diff --git a/packages/producer/scripts/build-fonts.mjs b/packages/core/scripts/build-fonts.mjs
similarity index 86%
rename from packages/producer/scripts/build-fonts.mjs
rename to packages/core/scripts/build-fonts.mjs
index faa209f57b..1d38524aa8 100644
--- a/packages/producer/scripts/build-fonts.mjs
+++ b/packages/core/scripts/build-fonts.mjs
@@ -2,7 +2,7 @@
 import { existsSync } from "node:fs";
 import { execSync } from "node:child_process";
 
-const target = "src/services/fontData.generated.ts";
+const target = "src/fonts/fontData.generated.ts";
 
 if (existsSync(target)) {
   console.log("[build:fonts] skipped — fontData.generated.ts already exists");
diff --git a/packages/producer/scripts/generate-font-data.ts b/packages/core/scripts/generate-font-data.ts
similarity index 98%
rename from packages/producer/scripts/generate-font-data.ts
rename to packages/core/scripts/generate-font-data.ts
index 76925207d2..01614c6420 100644
--- a/packages/producer/scripts/generate-font-data.ts
+++ b/packages/core/scripts/generate-font-data.ts
@@ -159,7 +159,7 @@ function main() {
   lines.push("]);");
   lines.push("");
 
-  const outputPath = resolve(__dirname, "../src/services/fontData.generated.ts");
+  const outputPath = resolve(__dirname, "../src/fonts/fontData.generated.ts");
   writeFileSync(outputPath, lines.join("\n"), "utf8");
   console.log(
     `[generate-font-data] Wrote ${entries.length} font faces (${Math.round(totalBytes / 1024)}KB) → ${outputPath}`,
diff --git a/packages/producer/src/services/authoredGoogleFonts.test.ts b/packages/core/src/fonts/authoredGoogleFonts.test.ts
similarity index 97%
rename from packages/producer/src/services/authoredGoogleFonts.test.ts
rename to packages/core/src/fonts/authoredGoogleFonts.test.ts
index bc52c95ab4..44aa7800f4 100644
--- a/packages/producer/src/services/authoredGoogleFonts.test.ts
+++ b/packages/core/src/fonts/authoredGoogleFonts.test.ts
@@ -1,4 +1,5 @@
-import { expect, it } from "bun:test";
+// @vitest-environment node
+import { expect, it } from "vitest";
 import { authoredGoogleFontStylesheets, withPageText } from "./authoredGoogleFonts.js";
 
 const url = "https://fonts.googleapis.com/css2?family=Fraunces:wght@400";
diff --git a/packages/producer/src/services/authoredGoogleFonts.ts b/packages/core/src/fonts/authoredGoogleFonts.ts
similarity index 100%
rename from packages/producer/src/services/authoredGoogleFonts.ts
rename to packages/core/src/fonts/authoredGoogleFonts.ts
diff --git a/packages/producer/src/services/deterministicFonts-aliasSupplement.test.ts b/packages/core/src/fonts/deterministicFonts-aliasSupplement.test.ts
similarity index 99%
rename from packages/producer/src/services/deterministicFonts-aliasSupplement.test.ts
rename to packages/core/src/fonts/deterministicFonts-aliasSupplement.test.ts
index 186abb3e19..2e1925cfc7 100644
--- a/packages/producer/src/services/deterministicFonts-aliasSupplement.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-aliasSupplement.test.ts
@@ -1,3 +1,4 @@
+// @vitest-environment node
 /**
  * Regression test for cross-typeface alias supplementation.
  *
@@ -16,7 +17,7 @@
  * so they are hermetic.
  */
 
-import { afterAll, beforeAll, beforeEach, describe, expect, it } from "bun:test";
+import { afterAll, beforeAll, beforeEach, describe, expect, it } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -294,7 +295,7 @@ describe("aliased font-family supplementation", () => {
     // The supplementary fetch is skipped outright when this lookup fails, so
     // every alias must resolve or its family silently loses Google's weights.
     for (const alias of Object.keys(FONT_ALIAS_MAP)) {
-      expect(resolveAliasDisplayName(alias)).toBeString();
+      expect(resolveAliasDisplayName(alias)).toEqual(expect.any(String));
     }
   });
 
diff --git a/packages/producer/src/services/deterministicFonts-authoredResources.test.ts b/packages/core/src/fonts/deterministicFonts-authoredResources.test.ts
similarity index 95%
rename from packages/producer/src/services/deterministicFonts-authoredResources.test.ts
rename to packages/core/src/fonts/deterministicFonts-authoredResources.test.ts
index 704fd113bc..e5d459dcf8 100644
--- a/packages/producer/src/services/deterministicFonts-authoredResources.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-authoredResources.test.ts
@@ -1,4 +1,5 @@
-import { afterEach, beforeEach, expect, it, spyOn } from "bun:test";
+// @vitest-environment node
+import { afterEach, beforeEach, expect, it, vi } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -18,7 +19,7 @@ beforeEach(() => {
   process.env.HYPERFRAMES_FONT_CACHE_DIR = cacheDir;
   requests.length = 0;
   _clearGoogleFontCssCacheForTests();
-  const mock = spyOn(globalThis, "fetch").mockImplementation(async (input) => {
+  const mock = vi.spyOn(globalThis, "fetch").mockImplementation(async (input) => {
     const url = new URL(String(input));
     requests.push(url.href);
     if (url.hostname === "fonts.googleapis.com") {
diff --git a/packages/producer/src/services/deterministicFonts-bundledStylesheet.test.ts b/packages/core/src/fonts/deterministicFonts-bundledStylesheet.test.ts
similarity index 94%
rename from packages/producer/src/services/deterministicFonts-bundledStylesheet.test.ts
rename to packages/core/src/fonts/deterministicFonts-bundledStylesheet.test.ts
index 952e28a974..90bc781f27 100644
--- a/packages/producer/src/services/deterministicFonts-bundledStylesheet.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-bundledStylesheet.test.ts
@@ -1,4 +1,5 @@
-import { afterEach, expect, it, spyOn } from "bun:test";
+// @vitest-environment node
+import { afterEach, expect, it, vi } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -9,7 +10,7 @@ import {
 
 const previousCacheDir = process.env.HYPERFRAMES_FONT_CACHE_DIR;
 const cacheDir = mkdtempSync(join(tmpdir(), "hf-bundled-stylesheet-"));
-const fetchMock = spyOn(globalThis, "fetch");
+const fetchMock = vi.spyOn(globalThis, "fetch");
 
 afterEach(() => {
   fetchMock.mockRestore();
diff --git a/packages/producer/src/services/deterministicFonts-bundledSubset.test.ts b/packages/core/src/fonts/deterministicFonts-bundledSubset.test.ts
similarity index 91%
rename from packages/producer/src/services/deterministicFonts-bundledSubset.test.ts
rename to packages/core/src/fonts/deterministicFonts-bundledSubset.test.ts
index 48e091efc1..181bd733b3 100644
--- a/packages/producer/src/services/deterministicFonts-bundledSubset.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-bundledSubset.test.ts
@@ -1,19 +1,18 @@
+// @vitest-environment node
 /**
  * Regression test for the coverage a bundled face claims.
  *
  * `scripts/generate-font-data.ts` embeds the `-latin-` subset file of every
  * canonical family, so an embedded face carries only Google's `latin` subset.
- * The emitted `@font-face` used to omit `unicode-range` — advertising full
- * coverage — and the supplementary Google fetch then skipped every subset of a
- * weight the bundle "covered". A bundled family therefore could not render the
- * scripts its own subset omits: `Noto Sans JP` weight 400 carries 218
- * codepoints with no kana and no kanji.
+ * The emitted `@font-face` therefore carries the latin `unicode-range`, and the
+ * supplementary Google fetch fills the subsets it omits: `Noto Sans JP` weight
+ * 400 carries 218 codepoints with no kana and no kanji.
  *
  * These tests inject `fetchImpl` (no network) and a temp
  * `HYPERFRAMES_FONT_CACHE_DIR` so they are hermetic.
  */
 
-import { afterAll, beforeAll, describe, expect, it } from "bun:test";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -106,7 +105,7 @@ describe("bundled Latin precedence", () => {
     const fetchImpl = (async (input: unknown) => {
       const url = String(input);
       if (url.startsWith("https://fonts.googleapis.com/")) {
-        expect(new URL(url).searchParams.get("family")).toStartWith("Inter:");
+        expect(new URL(url).searchParams.get("family")).toMatch(/^Inter:/);
         return new Response(`@font-face {
           font-family: 'Inter'; font-style: normal; font-weight: 400;
           src: url(https://fonts.gstatic.com/s/inter/text-subset.woff2) format('woff2');
diff --git a/packages/producer/src/services/deterministicFonts-declaredAlias.test.ts b/packages/core/src/fonts/deterministicFonts-declaredAlias.test.ts
similarity index 99%
rename from packages/producer/src/services/deterministicFonts-declaredAlias.test.ts
rename to packages/core/src/fonts/deterministicFonts-declaredAlias.test.ts
index 9bc95368a5..d3803701cc 100644
--- a/packages/producer/src/services/deterministicFonts-declaredAlias.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-declaredAlias.test.ts
@@ -1,3 +1,4 @@
+// @vitest-environment node
 /**
  * Declared-family alias resolution.
  *
@@ -15,7 +16,7 @@
  * at a temp dir, so these tests are hermetic.
  */
 
-import { afterAll, beforeEach, describe, expect, it } from "bun:test";
+import { afterAll, beforeEach, describe, expect, it } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
diff --git a/packages/producer/src/services/deterministicFonts-failClosed.test.ts b/packages/core/src/fonts/deterministicFonts-failClosed.test.ts
similarity index 96%
rename from packages/producer/src/services/deterministicFonts-failClosed.test.ts
rename to packages/core/src/fonts/deterministicFonts-failClosed.test.ts
index 359e03e111..2be9000a08 100644
--- a/packages/producer/src/services/deterministicFonts-failClosed.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-failClosed.test.ts
@@ -1,3 +1,4 @@
+// @vitest-environment node
 /**
  * Tests for `injectDeterministicFontFaces`'s `failClosedFontFetch` gate.
  *
@@ -14,8 +15,7 @@
  * The tests inject `fetchImpl` so no real network call happens.
  */
 
-import { afterEach, beforeEach, describe, expect, it, spyOn } from "bun:test";
-import { defaultLogger } from "../logger.js";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import {
   _clearGoogleFontCssCacheForTests,
   FONT_FETCH_FAILED,
@@ -106,6 +106,23 @@ describe("injectDeterministicFontFaces — failClosedFontFetch: false (default)"
     expect(result.includes("data-hyperframes-deterministic-fonts")).toBe(false);
   });
 
+  it("sends its warnings to the caller's logger instead of the console", async () => {
+    const consoleWarn = vi.spyOn(console, "warn").mockImplementation(() => {});
+    const warn = vi.fn();
+    try {
+      await injectDeterministicFontFaces(HTML_REQUESTING_UNRESOLVED_FONT, {
+        failClosedFontFetch: false,
+        allowSystemFontCapture: false,
+        fetchImpl: makeFailingFetch(),
+        logger: { warn, info: vi.fn() },
+      });
+      expect(warn).toHaveBeenCalled();
+      expect(consoleWarn).not.toHaveBeenCalled();
+    } finally {
+      consoleWarn.mockRestore();
+    }
+  });
+
   it("swallows a 404 response and returns the original HTML (no throw)", async () => {
     const result = await injectDeterministicFontFaces(HTML_REQUESTING_UNRESOLVED_FONT, {
       failClosedFontFetch: false,
@@ -431,10 +448,10 @@ describe("fail-closed fonts named only in an undefined var() fallback", () => {
       `body { font-family: var(--brand, "Acme Brand Sans", sans-serif); }`,
     );
     let warnings: string[] = [];
-    let warnSpy: ReturnType<typeof spyOn>;
+    let warnSpy: ReturnType<typeof vi.spyOn>;
     beforeEach(() => {
       warnings = [];
-      warnSpy = spyOn(defaultLogger, "warn").mockImplementation((message: string) => {
+      warnSpy = vi.spyOn(console, "warn").mockImplementation((message: string) => {
         warnings.push(message);
       });
     });
diff --git a/packages/producer/src/services/deterministicFonts-googleSubsets.test.ts b/packages/core/src/fonts/deterministicFonts-googleSubsets.test.ts
similarity index 99%
rename from packages/producer/src/services/deterministicFonts-googleSubsets.test.ts
rename to packages/core/src/fonts/deterministicFonts-googleSubsets.test.ts
index 25018fa90b..4bdec0f468 100644
--- a/packages/producer/src/services/deterministicFonts-googleSubsets.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-googleSubsets.test.ts
@@ -1,3 +1,4 @@
+// @vitest-environment node
 /**
  * Regression test for the Google Fonts multi-subset cache collision.
  *
@@ -19,17 +20,18 @@
  * so they are hermetic.
  */
 
-import { afterAll, beforeAll, beforeEach, describe, expect, it } from "bun:test";
+import { afterAll, beforeAll, beforeEach, describe, expect, it } from "vitest";
 import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import { homedir, tmpdir } from "node:os";
 import { join } from "node:path";
 import { _clearGoogleFontCssCacheForTests } from "./deterministicFonts.js";
+import { fontDirectories } from "./systemFontLocator.js";
 
 beforeEach(() => _clearGoogleFontCssCacheForTests());
 
 let cacheDir: string;
 let prevCacheEnv: string | undefined;
-const LOCAL_FONT_DIR = join(homedir(), ".local", "share", "fonts");
+const LOCAL_FONT_DIR = fontDirectories().find((dir) => dir.startsWith(homedir()))!;
 const LOCAL_FONT_FILE = join(LOCAL_FONT_DIR, "hf-authored-fail-test.woff2");
 const LOCAL_FONT_BYTES = "LOCAL_ONLY_BYTES";
 
diff --git a/packages/producer/src/services/deterministicFonts-oblique.test.ts b/packages/core/src/fonts/deterministicFonts-oblique.test.ts
similarity index 93%
rename from packages/producer/src/services/deterministicFonts-oblique.test.ts
rename to packages/core/src/fonts/deterministicFonts-oblique.test.ts
index 8a3c9962fb..49e7334e2b 100644
--- a/packages/producer/src/services/deterministicFonts-oblique.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-oblique.test.ts
@@ -1,4 +1,5 @@
-import { afterEach, beforeEach, expect, it, spyOn } from "bun:test";
+// @vitest-environment node
+import { afterEach, beforeEach, expect, it, vi } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -30,7 +31,7 @@ it.each(["oblique", "oblique 10deg", "oblique 0deg 10deg", "oblique -12.5deg 2.5
   "embeds every subset of an authored %s face in fail-closed mode",
   async (style) => {
     const subsets = ["U+0000-00FF", "U+0100-017F"];
-    const fetchMock = spyOn(globalThis, "fetch").mockImplementation(async (input) => {
+    const fetchMock = vi.spyOn(globalThis, "fetch").mockImplementation(async (input) => {
       const url = String(input);
       if (url.startsWith("https://fonts.googleapis.com/")) {
         return new Response(
diff --git a/packages/producer/src/services/deterministicFonts-order.test.ts b/packages/core/src/fonts/deterministicFonts-order.test.ts
similarity index 96%
rename from packages/producer/src/services/deterministicFonts-order.test.ts
rename to packages/core/src/fonts/deterministicFonts-order.test.ts
index beadec94aa..d2cdb22704 100644
--- a/packages/producer/src/services/deterministicFonts-order.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-order.test.ts
@@ -1,4 +1,5 @@
-import { afterAll, beforeAll, describe, expect, it } from "bun:test";
+// @vitest-environment node
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
diff --git a/packages/producer/src/services/deterministicFonts-retries.test.ts b/packages/core/src/fonts/deterministicFonts-retries.test.ts
similarity index 94%
rename from packages/producer/src/services/deterministicFonts-retries.test.ts
rename to packages/core/src/fonts/deterministicFonts-retries.test.ts
index 5dd7020bea..4822a4cc66 100644
--- a/packages/producer/src/services/deterministicFonts-retries.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-retries.test.ts
@@ -1,4 +1,5 @@
-import { afterAll, beforeAll, describe, expect, it } from "bun:test";
+// @vitest-environment node
+import { afterAll, beforeAll, describe, expect, it, vi } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -29,7 +30,7 @@ afterAll(() => {
 const FAST_RETRY = {
   maxAttempts: 2,
   attemptTimeoutMs: 20,
-  maxElapsedMs: 100,
+  maxElapsedMs: 10_000,
   baseDelayMs: 0,
 } as const;
 
@@ -264,7 +265,6 @@ describe("deterministic Google Fonts retries", () => {
     const result = injectWithRetries(html, fetchImpl, {
       ...FAST_RETRY,
       attemptTimeoutMs: 5,
-      maxElapsedMs: 50,
     });
 
     await expect(result).rejects.toMatchObject({ code: FONT_FETCH_UNAVAILABLE });
@@ -278,14 +278,11 @@ describe("deterministic Google Fonts retries", () => {
       calls += 1;
       return new Response("", {
         status: 429,
-        headers: { "Retry-After": "1" },
+        headers: { "Retry-After": "60" },
       });
     }) as typeof fetch;
 
-    const result = injectWithRetries(html, fetchImpl, {
-      ...FAST_RETRY,
-      maxElapsedMs: 100,
-    });
+    const result = injectWithRetries(html, fetchImpl);
 
     await expect(result).rejects.toMatchObject({ code: FONT_FETCH_UNAVAILABLE });
     expect(calls).toBe(1);
@@ -341,14 +338,20 @@ describe("deterministic Google Fonts retries", () => {
       });
     }) as typeof fetch;
 
-    const result = injectWithRetries(html, fetchImpl, {
-      maxAttempts: 2,
-      attemptTimeoutMs: 70,
-      maxElapsedMs: 100,
-      baseDelayMs: 0,
-    });
-
-    await expect(result).rejects.toMatchObject({ code: FONT_FETCH_UNAVAILABLE });
+    vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout", "Date"] });
+    try {
+      const result = injectWithRetries(html, fetchImpl, {
+        maxAttempts: 2,
+        attemptTimeoutMs: 70,
+        maxElapsedMs: 100,
+        baseDelayMs: 0,
+      });
+      const settled = expect(result).rejects.toMatchObject({ code: FONT_FETCH_UNAVAILABLE });
+      await vi.advanceTimersByTimeAsync(100);
+      await settled;
+    } finally {
+      vi.useRealTimers();
+    }
     expect(firstCalls).toBe(1);
     expect(secondCalls).toBe(1);
   });
diff --git a/packages/producer/src/services/deterministicFonts-systemCapture.test.ts b/packages/core/src/fonts/deterministicFonts-systemCapture.test.ts
similarity index 98%
rename from packages/producer/src/services/deterministicFonts-systemCapture.test.ts
rename to packages/core/src/fonts/deterministicFonts-systemCapture.test.ts
index 87c716b906..b817fd59a4 100644
--- a/packages/producer/src/services/deterministicFonts-systemCapture.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-systemCapture.test.ts
@@ -1,3 +1,4 @@
+// @vitest-environment node
 /**
  * Tests for the system font capture path (Path 3) in `buildFontFaceCss`.
  *
@@ -10,7 +11,7 @@
  * not served) so the resolver falls through to the system font path.
  */
 
-import { describe, expect, it } from "bun:test";
+import { describe, expect, it } from "vitest";
 import { existsSync } from "node:fs";
 import { fontFormatHint, injectDeterministicFontFaces } from "./deterministicFonts.js";
 
diff --git a/packages/producer/src/services/deterministicFonts-textSubset.test.ts b/packages/core/src/fonts/deterministicFonts-textSubset.test.ts
similarity index 99%
rename from packages/producer/src/services/deterministicFonts-textSubset.test.ts
rename to packages/core/src/fonts/deterministicFonts-textSubset.test.ts
index 5023e69e93..2f1d228e8e 100644
--- a/packages/producer/src/services/deterministicFonts-textSubset.test.ts
+++ b/packages/core/src/fonts/deterministicFonts-textSubset.test.ts
@@ -1,4 +1,5 @@
-import { describe, expect, it } from "bun:test";
+// @vitest-environment node
+import { describe, expect, it } from "vitest";
 import { injectDeterministicFontFaces } from "./deterministicFonts.js";
 
 async function requestedGoogleFontUrl(html: string): Promise<URL> {
diff --git a/packages/producer/src/services/deterministicFonts.test.ts b/packages/core/src/fonts/deterministicFonts.test.ts
similarity index 99%
rename from packages/producer/src/services/deterministicFonts.test.ts
rename to packages/core/src/fonts/deterministicFonts.test.ts
index 78bdac0b3c..1d572d2295 100644
--- a/packages/producer/src/services/deterministicFonts.test.ts
+++ b/packages/core/src/fonts/deterministicFonts.test.ts
@@ -1,4 +1,5 @@
-import { beforeEach, describe, expect, it } from "bun:test";
+// @vitest-environment node
+import { beforeEach, describe, expect, it } from "vitest";
 import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
diff --git a/packages/producer/src/services/deterministicFonts.ts b/packages/core/src/fonts/deterministicFonts.ts
similarity index 98%
rename from packages/producer/src/services/deterministicFonts.ts
rename to packages/core/src/fonts/deterministicFonts.ts
index 83848a4749..02c29a36cd 100644
--- a/packages/producer/src/services/deterministicFonts.ts
+++ b/packages/core/src/fonts/deterministicFonts.ts
@@ -2,13 +2,9 @@ import { createHash } from "node:crypto";
 import { existsSync, mkdirSync, mkdtempSync, readFileSync, writeFileSync } from "node:fs";
 import { homedir, tmpdir } from "node:os";
 import { join } from "node:path";
-import { defaultLogger } from "../logger.js";
 
-import { FONT_ALIAS_MAP, resolveAliasDisplayName } from "@hyperframes/core/fonts/aliases";
-import {
-  locateSystemFontVariants,
-  SYSTEM_FONT_SIZE_LIMIT,
-} from "@hyperframes/core/fonts/system-locator";
+import { FONT_ALIAS_MAP, resolveAliasDisplayName } from "./aliases.js";
+import { locateSystemFontVariants, SYSTEM_FONT_SIZE_LIMIT } from "./systemFontLocator.js";
 import { parseHTML } from "linkedom";
 import postcss, { type AtRule, type Declaration, type Rule } from "postcss";
 import { EMBEDDED_FONT_DATA } from "./fontData.generated.js";
@@ -68,6 +64,7 @@ const CSS_WIDE_KEYWORDS: ReadonlySet<string> = new Set([
  * Only top-level commas split: a `var(--x, fallback)` expression stays one
  * token, as does a comma inside a quoted family name.
  */
+// fallow-ignore-next-line complexity
 export function parseFontFamilyValue(value: string): string[] {
   const pieces: string[] = [];
   let start = 0;
@@ -472,11 +469,11 @@ const CANONICAL_FONTS: Record<string, CanonicalFontSpec> = {
   },
 };
 
-// FONT_ALIASES derives from the shared alias map in @hyperframes/core.
-// The cast is safe: every value in FONT_ALIAS_MAP is a valid CANONICAL_FONTS key.
+// FONT_ALIASES derives from the shared alias map; every FONT_ALIAS_MAP value is a CANONICAL_FONTS key.
 export const FONT_ALIASES = FONT_ALIAS_MAP as Record<string, keyof typeof CANONICAL_FONTS>;
 
-export { FONT_ALIAS_KEYS } from "@hyperframes/core/fonts/aliases";
+export { FONT_ALIAS_KEYS } from "./aliases.js";
+export { fontToDataUri } from "./fontCompression.js";
 
 function normalizeFamilyName(family: string): string {
   return family
@@ -752,6 +749,7 @@ async function googleFamilyFaceRules(
 async function systemFamilyFaceRules(
   lookupFamily: string,
   emitFamily: string,
+  log: FontLogger,
 ): Promise<string[] | null> {
   const variants = locateSystemFontVariants(lookupFamily);
   if (variants.length === 0) return null;
@@ -764,11 +762,11 @@ async function systemFamilyFaceRules(
     rules.push(buildFontFaceRule(emitFamily, dataUri, variant.weight, variant.style));
   }
   if (totalBytes > SYSTEM_FONT_SIZE_LIMIT) {
-    defaultLogger.warn(
+    log.warn(
       `[Compiler] System font "${lookupFamily}" is large (${(totalBytes / 1024 / 1024).toFixed(1)} MB total across ${variants.length} variant(s)) — embedding anyway. Consider font subsetting for production.`,
     );
   }
-  defaultLogger.info(
+  log.info(
     `[Compiler] Embedded system font "${lookupFamily}" — ${variants.length} variant(s), ${(totalBytes / 1024).toFixed(0)} KB total`,
   );
   return rules;
@@ -799,7 +797,7 @@ async function resolveFamilyFaceRules(
   return (
     (await googleFamilyFaceRules(lookupFamily, emitFamily, optional, options, fontText)) ??
     (options.allowSystemFontCapture && !pageNamedThisFile(lookupFamily, options)
-      ? await systemFamilyFaceRules(lookupFamily, emitFamily)
+      ? await systemFamilyFaceRules(lookupFamily, emitFamily, options.log)
       : null)
   );
 }
@@ -989,7 +987,7 @@ async function resolveDeclaredFamilyAlias(
   }
   if (!rules) return null;
 
-  defaultLogger.warn(
+  options.log.warn(
     `[Compiler] font-family "${authoredFamily}" is not a known family; resolved it to "${declared.family}", ` +
       `which this document declares. Correct the authored font-family to "${declared.family}".`,
   );
@@ -1044,7 +1042,7 @@ async function buildFontFaceCss(
   };
 }
 
-function warnUnresolvedFonts(unresolved: string[]): void {
+function warnUnresolvedFonts(unresolved: string[], log: FontLogger): void {
   const mapped = Object.entries(FONT_ALIASES)
     .reduce<string[]>((acc, [alias, canonical]) => {
       const display = alias === canonical ? alias : `${alias} → ${canonical}`;
@@ -1052,7 +1050,7 @@ function warnUnresolvedFonts(unresolved: string[]): void {
       return acc;
     }, [])
     .sort();
-  defaultLogger.warn(
+  log.warn(
     `[Compiler] No deterministic font mapping for: ${unresolved.join(", ")}\n` +
       `  Mapped fonts: ${mapped.join(", ")}\n` +
       `  To fix, pick one:\n` +
@@ -1109,7 +1107,7 @@ function fontCacheDir(slug: string): string {
       const fallback = join(ephemeralFontCacheRoot, slug);
       mkdirSync(fallback, { recursive: true });
       if (firstFallback) {
-        defaultLogger.warn(
+        STDERR_LOGGER.warn(
           `Font cache directory is unwritable (${dir}). ` +
             `Using temporary fallback — fonts will re-download each run. ` +
             `Fix with: chmod 755 ${resolveFontCacheRoot()}`,
@@ -1213,6 +1211,7 @@ const DEFAULT_FONT_FETCH_RETRY_POLICY: FontFetchRetryPolicy = {
 
 /** Internal threading of the failClosed flag + fetch override through callers. */
 interface InternalFontFetchOptions {
+  log: FontLogger;
   failClosedFontFetch: boolean;
   fetchImpl: typeof fetch;
   allowSystemFontCapture: boolean;
@@ -1613,7 +1612,7 @@ async function fetchGoogleFontStylesheet(
   }
 
   if (faces.length > 0) {
-    defaultLogger.info(
+    options.log.info(
       `[Compiler] Fetched ${faces.length} font face(s) for "${familyName}" from Google Fonts (cached to ${fontCacheDir(slug)})`,
     );
   }
@@ -1638,7 +1637,7 @@ async function fetchFamilyFaces(
     );
   } catch (err) {
     if (!(err instanceof FontFetchUnavailableError)) throw err;
-    defaultLogger.warn(
+    options.log.warn(
       `[Compiler] Optional font "${familyName}" is unavailable, rendering its fallback: ${err.message}`,
     );
     return [];
@@ -1650,7 +1649,18 @@ async function fetchFamilyFaces(
 /**
  * Options for {@link injectDeterministicFontFaces}.
  */
+export interface FontLogger {
+  warn(message: string): void;
+  info(message: string): void;
+}
+
+const STDERR_LOGGER: FontLogger = {
+  warn: (message) => console.warn(`[WARN] ${message}`),
+  info: (message) => console.error(`[INFO] ${message}`),
+};
+
 export interface InjectDeterministicFontFacesOptions {
+  logger?: FontLogger;
   /**
    * When `true`, exhausted transient fetch failures of a required family throw
    * {@link FontFetchUnavailableError} with code `FONT_FETCH_UNAVAILABLE`;
@@ -1863,6 +1873,7 @@ export async function injectDeterministicFontFaces(
   const allowSystemFontCapture = options.allowSystemFontCapture !== false;
   const retryPolicy = resolveFontFetchRetryPolicy(options.fontFetchRetryPolicy);
   const fetchOptions: InternalFontFetchOptions = {
+    log: options.logger ?? STDERR_LOGGER,
     failClosedFontFetch,
     fetchImpl,
     allowSystemFontCapture,
@@ -1910,7 +1921,7 @@ export async function injectDeterministicFontFaces(
   }
   if (!css) {
     if (unresolved.length > 0) {
-      warnUnresolvedFonts(unresolved);
+      warnUnresolvedFonts(unresolved, fetchOptions.log);
     }
     return html;
   }
@@ -1926,11 +1937,11 @@ export async function injectDeterministicFontFaces(
   styleEl.textContent = css;
   placeAfterEveryStylesheet(document, head, styleEl);
 
-  defaultLogger.info(
+  fetchOptions.log.info(
     `[Compiler] Injected deterministic @font-face rules for ${pendingFamilies.size - unresolved.length} requested font families`,
   );
   if (unresolved.length > 0) {
-    warnUnresolvedFonts(unresolved);
+    warnUnresolvedFonts(unresolved, fetchOptions.log);
   }
 
   return document.toString();
diff --git a/packages/producer/src/services/fontCompression.test.ts b/packages/core/src/fonts/fontCompression.test.ts
similarity index 82%
rename from packages/producer/src/services/fontCompression.test.ts
rename to packages/core/src/fonts/fontCompression.test.ts
index 07af822d41..4c20358a0d 100644
--- a/packages/producer/src/services/fontCompression.test.ts
+++ b/packages/core/src/fonts/fontCompression.test.ts
@@ -1,43 +1,21 @@
-import { describe, expect, it, spyOn } from "bun:test";
-import {
-  existsSync,
-  mkdirSync,
-  mkdtempSync,
-  readFileSync,
-  readdirSync,
-  rmSync,
-  writeFileSync,
-} from "node:fs";
+// @vitest-environment node
+import { describe, expect, it, vi } from "vitest";
+import { mkdirSync, mkdtempSync, readFileSync, readdirSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
+import { fileURLToPath } from "node:url";
 import { compressToWoff2, fontToDataUri } from "./fontCompression.js";
 
-/**
- * Locate a system TTF font for real compression tests. macOS ships plenty
- * of .ttf files in /System/Library/Fonts/Supplemental; we pick the first
- * one found from a short list. Returns null on Linux CI or any environment
- * without the expected fonts — those tests are skipped gracefully.
- */
-function findSystemTtf(): Buffer | null {
-  const candidates = [
-    "/System/Library/Fonts/Supplemental/Andale Mono.ttf",
-    "/System/Library/Fonts/Supplemental/Courier New.ttf",
-    "/System/Library/Fonts/Supplemental/Arial.ttf",
-    "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf",
-  ];
-  for (const path of candidates) {
-    if (existsSync(path)) return readFileSync(path);
-  }
-  return null;
-}
+const GEIST_TTF = fileURLToPath(
+  new URL(
+    "../../../../docs/public/catalog/items/frost-sequence-camera-orbit/assets/fonts/Geist-Regular.ttf",
+    import.meta.url,
+  ),
+);
 
 describe("compressToWoff2", () => {
   it("compresses a TTF buffer to a smaller woff2 buffer", async () => {
-    const ttf = findSystemTtf();
-    if (!ttf) {
-      console.warn("Skipping: no system TTF font available");
-      return;
-    }
+    const ttf = readFileSync(GEIST_TTF);
     const woff2 = await compressToWoff2(ttf);
     expect(woff2).toBeInstanceOf(Buffer);
     expect(woff2.length).toBeGreaterThan(0);
@@ -56,7 +34,7 @@ describe("fontToDataUri", () => {
     const raw = Buffer.from("stable-font-content");
     const compressed = Buffer.from("compressed-font-content");
     const compressImpl = async () => compressed;
-    const clock = spyOn(Date, "now").mockReturnValue(1234567890);
+    const clock = vi.spyOn(Date, "now").mockReturnValue(1234567890);
     try {
       const first = await fontToDataUri(raw, "ttf", { cacheDir, compressImpl });
       const [cacheName] = readdirSync(cacheDir);
@@ -139,11 +117,7 @@ describe("fontToDataUri", () => {
   });
 
   it("compresses a TTF and returns a woff2 data URI", async () => {
-    const ttf = findSystemTtf();
-    if (!ttf) {
-      console.warn("Skipping: no system TTF font available");
-      return;
-    }
+    const ttf = readFileSync(GEIST_TTF);
     const uri = await fontToDataUri(ttf, "ttf");
     expect(uri).toMatch(/^data:font\/woff2;base64,/);
     const naiveLength = `data:font/ttf;base64,${ttf.toString("base64")}`.length;
diff --git a/packages/producer/src/services/fontCompression.ts b/packages/core/src/fonts/fontCompression.ts
similarity index 96%
rename from packages/producer/src/services/fontCompression.ts
rename to packages/core/src/fonts/fontCompression.ts
index ad4c5cfe11..1578aae98c 100644
--- a/packages/producer/src/services/fontCompression.ts
+++ b/packages/core/src/fonts/fontCompression.ts
@@ -1,4 +1,4 @@
-// @ts-expect-error -- wawoff2 ships no type declarations; ambient .d.ts only visible to producer's own tsconfig
+// @ts-expect-error -- wawoff2 ships no type declarations
 import wawoff2 from "wawoff2";
 import { createHash } from "node:crypto";
 import {
diff --git a/packages/producer/src/services/fontData.generated.ts b/packages/core/src/fonts/fontData.generated.ts
similarity index 100%
rename from packages/producer/src/services/fontData.generated.ts
rename to packages/core/src/fonts/fontData.generated.ts
diff --git a/packages/gcp-cloud-run/Dockerfile b/packages/gcp-cloud-run/Dockerfile
index 26196e803d..84417f2021 100644
--- a/packages/gcp-cloud-run/Dockerfile
+++ b/packages/gcp-cloud-run/Dockerfile
@@ -142,8 +142,8 @@ COPY packages/studio-server/ packages/studio-server/
 
 # Build workspace dependencies before the producer bundle. The published
 # workspace packages are not prebuilt in a fresh clone, so producer's esbuild
-# resolution otherwise fails on parsers/core compiler entrypoints. Generate
-# embedded font data so glyph layout matches production.
+# resolution otherwise fails on parsers/core compiler entrypoints. Core's build
+# also generates the embedded font data, so glyph layout matches production.
 RUN bun run --cwd packages/parsers build \
     && bun run --cwd packages/lint build \
     && bun run --cwd packages/studio-server build \
@@ -152,7 +152,6 @@ RUN bun run --cwd packages/parsers build \
     && bun run --cwd packages/sdk build \
     && bun run --cwd packages/sdk-playground build \
     && bun run --cwd packages/engine build \
-    && (cd packages/producer && bunx tsx scripts/generate-font-data.ts) \
     && bun run --cwd packages/producer build \
     && bun run --cwd packages/gcp-cloud-run build
 
diff --git a/packages/parsers/src/fontAliases.ts b/packages/parsers/src/fontAliases.ts
index 9328f0dc5a..0b87d99e1d 100644
--- a/packages/parsers/src/fontAliases.ts
+++ b/packages/parsers/src/fontAliases.ts
@@ -4,7 +4,7 @@
  * eliminating manual drift between the two.
  *
  * Keys are lowercase font family names. Values are canonical font slugs
- * matching CANONICAL_FONTS keys in the producer's deterministicFonts module.
+ * matching CANONICAL_FONTS keys in core's fonts/deterministicFonts module.
  */
 export const FONT_ALIAS_MAP = {
   // ── Canonical bundled fonts (self-referencing) ────────────────────────
diff --git a/packages/producer/package.json b/packages/producer/package.json
index 135ee5cd42..11f7302a71 100644
--- a/packages/producer/package.json
+++ b/packages/producer/package.json
@@ -42,8 +42,7 @@
     "registry": "https://registry.npmjs.org/"
   },
   "scripts": {
-    "build": "bun run build:fonts && bun run build:hf-early-stub && bun run --cwd ../.. build:hyperframes-runtime:modular && node build.mjs",
-    "build:fonts": "node scripts/build-fonts.mjs",
+    "build": "bun run build:hf-early-stub && bun run --cwd ../.. build:hyperframes-runtime:modular && node build.mjs",
     "build:hf-early-stub": "bun run scripts/build-hf-early-stub.ts",
     "typecheck": "tsc --noEmit",
     "parity:check": "tsx src/parity-harness.ts",
@@ -76,17 +75,6 @@
     "prepublishOnly": "echo skip"
   },
   "dependencies": {
-    "@fontsource/archivo-black": "^5.2.8",
-    "@fontsource/eb-garamond": "^5.2.7",
-    "@fontsource/ibm-plex-mono": "^5.2.7",
-    "@fontsource/inter": "^5.2.8",
-    "@fontsource/jetbrains-mono": "^5.2.8",
-    "@fontsource/league-gothic": "^5.2.8",
-    "@fontsource/montserrat": "^5.2.8",
-    "@fontsource/nunito": "^5.2.7",
-    "@fontsource/oswald": "^5.2.8",
-    "@fontsource/outfit": "^5.2.8",
-    "@fontsource/space-mono": "^5.2.9",
     "@hono/node-server": "^2.0.5",
     "@hyperframes/core": "workspace:^",
     "@hyperframes/engine": "workspace:^",
@@ -97,17 +85,9 @@
     "linkedom": "^0.18.12",
     "postcss": "^8.4.0",
     "puppeteer": "^25.2.1",
-    "puppeteer-core": "^25.2.1",
-    "wawoff2": "^2.0.1"
+    "puppeteer-core": "^25.2.1"
   },
   "devDependencies": {
-    "@fontsource/lato": "^5.2.7",
-    "@fontsource/noto-sans-jp": "^5.2.9",
-    "@fontsource/open-sans": "^5.2.7",
-    "@fontsource/playfair-display": "^5.2.8",
-    "@fontsource/poppins": "^5.2.7",
-    "@fontsource/roboto": "^5.2.10",
-    "@fontsource/source-code-pro": "^5.2.7",
     "@hyperframes/aws-lambda": "workspace:*",
     "@types/node": "^25.0.10",
     "@webgpu/types": "^0.1.69",
diff --git a/packages/producer/scripts/test-classification.mjs b/packages/producer/scripts/test-classification.mjs
index 6834d68ff5..57b205da19 100644
--- a/packages/producer/scripts/test-classification.mjs
+++ b/packages/producer/scripts/test-classification.mjs
@@ -14,7 +14,6 @@ const INTEGRATION_TEST_FILES = new Set([
   "src/regression-harness-psnr.test.ts",
   "src/services/bundleScriptPolicy.test.ts",
   "src/services/coreRuntimeBrowser.test.ts",
-  "src/services/deterministicFonts-systemCapture.test.ts",
   "src/services/vfxDeterminism.test.ts",
   "src/services/distributed/assemble.test.ts",
   "src/services/distributed/chunkBoundary.test.ts",
diff --git a/packages/producer/src/index.ts b/packages/producer/src/index.ts
index ae9ad20660..e9b900e997 100644
--- a/packages/producer/src/index.ts
+++ b/packages/producer/src/index.ts
@@ -129,7 +129,7 @@ export {
   type FontFetchErrorCode,
   type FontFetchRetryPolicy,
   type InjectDeterministicFontFacesOptions,
-} from "./services/deterministicFonts.js";
+} from "@hyperframes/core/fonts/embed";
 export { quantizeTimeToFrame } from "./utils/parityContract.js";
 export { resolveRenderPaths, type RenderPaths } from "./utils/paths.js";
 
diff --git a/packages/producer/src/services/distributed/plan.ts b/packages/producer/src/services/distributed/plan.ts
index e6652bf808..93edeafa31 100644
--- a/packages/producer/src/services/distributed/plan.ts
+++ b/packages/producer/src/services/distributed/plan.ts
@@ -661,13 +661,13 @@ export function buildChunkSlices(
  * distributed pipeline needs it.
  */
 async function readFontSnapshotSha(): Promise<string> {
-  const module = (await import("../fontData.generated.js")) as {
+  const module = (await import("@hyperframes/core/fonts/embedded-data")) as {
     EMBEDDED_FONT_DATA?: unknown;
   };
   const data = module.EMBEDDED_FONT_DATA;
   if (!data || typeof data !== "object") {
     throw new Error(
-      "[plan] EMBEDDED_FONT_DATA missing from fontData.generated.js — was `bun run build:fonts` run?",
+      "[plan] EMBEDDED_FONT_DATA missing from @hyperframes/core/fonts/embedded-data — was `bun run build:fonts` run?",
     );
   }
   // Hash a canonical key fingerprint, not the raw font bytes — the bytes are
diff --git a/packages/producer/src/services/htmlCompiler.ts b/packages/producer/src/services/htmlCompiler.ts
index 9a186184b6..e603fd5858 100644
--- a/packages/producer/src/services/htmlCompiler.ts
+++ b/packages/producer/src/services/htmlCompiler.ts
@@ -88,7 +88,7 @@ import type { Page } from "puppeteer-core";
 import {
   injectDeterministicFontFaces,
   normalizeSystemFontPrimaryFamilies,
-} from "./deterministicFonts.js";
+} from "@hyperframes/core/fonts/embed";
 import { prepareAnimatedGifInputs } from "./animatedGifPrep.js";
 import { createStudioPositionSeekReapplyScript } from "@hyperframes/studio-server/manual-edits-render-script";
 import { getPositionEditsRenderScript } from "@hyperframes/core/runtime/position-edits-render";
@@ -1777,7 +1777,7 @@ async function readLocalFont(absPath: string): Promise<LocalFontRead> {
 
 // fallow-ignore-next-line complexity
 async function embedLocalFontFaces(html: string, projectDir: string): Promise<string> {
-  const { fontToDataUri: toDataUri } = await import("./fontCompression.js");
+  const { fontToDataUri: toDataUri } = await import("@hyperframes/core/fonts/embed");
   const styleBlockRe = /<style\b[^>]*>([\s\S]*?)<\/style>/gi;
   const fontFaceRe = /@font-face\s*\{([^}]*)\}/gi;
   let result = html;
@@ -2018,6 +2018,7 @@ export async function compileForRender(
   );
 
   const coalescedHtml = await injectDeterministicFontFaces(normalizedFontHtml, {
+    logger: defaultLogger,
     failClosedFontFetch: options.failClosedFontFetch === true,
     allowSystemFontCapture: options.allowSystemFontCapture,
     abortSignal: options.abortSignal,
diff --git a/packages/producer/src/services/render/planValidation.ts b/packages/producer/src/services/render/planValidation.ts
index 0ad2f21742..3415938fff 100644
--- a/packages/producer/src/services/render/planValidation.ts
+++ b/packages/producer/src/services/render/planValidation.ts
@@ -11,7 +11,7 @@ import {
   GENERIC_FAMILIES,
   iterateFontFamilyDeclarations,
   resolveFontFamilyDeclarationFamilies,
-} from "../deterministicFonts.js";
+} from "@hyperframes/core/fonts/embed";
 
 /**
  * Re-export the BROWSER_GPU_NOT_SOFTWARE code so distributed adapters and
@@ -25,7 +25,7 @@ export { BROWSER_GPU_NOT_SOFTWARE } from "@hyperframes/engine";
  * @font-face injector consume the same surface, so the parser lives next to
  * the data.
  */
-export { parseFontFamilyValue } from "../deterministicFonts.js";
+export { parseFontFamilyValue } from "@hyperframes/core/fonts/embed";
 
 /**
  * Typed plan-validation error. Workflow adapters key retry policies off the
diff --git a/packages/studio/vite.adapter.ts b/packages/studio/vite.adapter.ts
index 76c1815de0..3d445262df 100644
--- a/packages/studio/vite.adapter.ts
+++ b/packages/studio/vite.adapter.ts
@@ -282,8 +282,8 @@ export function createViteAdapter(
     },
 
     async transformPreviewHtml({ html }) {
-      const producer = await import("../producer/src/services/deterministicFonts.js");
-      return producer.injectDeterministicFontFaces(html);
+      const fonts = await import("../core/src/fonts/deterministicFonts.js");
+      return fonts.injectDeterministicFontFaces(html);
     },
 
     getProjectSignature(projectDir: string): string {
diff --git a/scripts/test-reachability.json b/scripts/test-reachability.json
index cc85cee8a9..19ca15cddb 100644
--- a/scripts/test-reachability.json
+++ b/scripts/test-reachability.json
@@ -61,7 +61,7 @@
       ],
       "sources": {
         "packages/producer/scripts/run-test-lane.mjs": "bff02680f19eebcce0df72cdeedbbc05edfdcede3f3f60658fc0cb18ed8c59f6",
-        "packages/producer/scripts/test-classification.mjs": "e16151bbd3a3f9767e513fdfb1155fad286855e1b9ffb077ace80d3fe900bd16",
+        "packages/producer/scripts/test-classification.mjs": "1c0490f70042787a081a47ffe70fb8688785015cbf50fbbce712ba1fa1cca889",
         ".github/workflows/ci.yml#job#producer-source-tests": "45da72aa6cf08cdfd5bcf5311e89f12af4842f9eebc6735df19da8c02f4d4864",
         "packages/producer/package.json#script#test:unit": "ae6beda8319d166774be958ea5593cd27dbf7f6c9bce1d787a3fe28dfc3477b1",
         "packages/producer/package.json#script#test:integration": "008589f37d026877595a13501cbb66abd5cbe50e21fdcac6904f45466c3f475d",