fix(runtime): honor render fps for deterministic seeks

packages/core/src/runtime/init.test.ts

@@ -109,6 +109,7 @@ describe("initSandboxRuntimeModular", () => {
     delete window.__player;
     delete window.__playerReady;
     delete window.__renderReady;
+    delete (window as { __HF_EXPORT_RENDER_SEEK_CONFIG?: unknown }).__HF_EXPORT_RENDER_SEEK_CONFIG;
     delete window.__hfTimelinesBuilding;
     delete (window as { THREE?: unknown }).THREE;
     vi.restoreAllMocks();
@@ -146,6 +147,99 @@ describe("initSandboxRuntimeModular", () => {
     expect(child.style.visibility).toBe("visible");
   });
 
+  it("uses export render fps when quantizing renderSeek", () => {
+    const infoSpy = vi.spyOn(console, "info").mockImplementation(() => {});
+    const root = document.createElement("div");
+    root.setAttribute("data-composition-id", "main");
+    root.setAttribute("data-root", "true");
+    root.setAttribute("data-start", "0");
+    root.setAttribute("data-duration", "1");
+    root.setAttribute("data-width", "1920");
+    root.setAttribute("data-height", "1080");
+    document.body.appendChild(root);
+
+    const timeline = createMockTimeline(1);
+    window.__timelines = { main: timeline };
+    (
+      window as {
+        __HF_EXPORT_RENDER_SEEK_CONFIG?: { fps: number; fpsSource: "render-options" };
+      }
+    ).__HF_EXPORT_RENDER_SEEK_CONFIG = {
+      fps: 60,
+      fpsSource: "render-options",
+    };
+
+    initSandboxRuntimeModular();
+
+    window.__player?.renderSeek(1 / 60);
+
+    expect(timeline.time()).toBeCloseTo(1 / 60, 6);
+    expect(infoSpy).toHaveBeenCalledWith(
+      "[hyperframes] render runtime fps",
+      expect.objectContaining({
+        canonicalFps: 60,
+        source: "render-options",
+        rawFpsSource: "render-options",
+        rawFps: 60,
+      }),
+    );
+  });
+
+  it("surfaces unknown export render fps sources without collapsing them to render-options", () => {
+    const infoSpy = vi.spyOn(console, "info").mockImplementation(() => {});
+    const root = document.createElement("div");
+    root.setAttribute("data-composition-id", "main");
+    root.setAttribute("data-root", "true");
+    root.setAttribute("data-start", "0");
+    root.setAttribute("data-duration", "1");
+    root.setAttribute("data-width", "1920");
+    root.setAttribute("data-height", "1080");
+    document.body.appendChild(root);
+
+    window.__timelines = { main: createMockTimeline(1) };
+    (
+      window as {
+        __HF_EXPORT_RENDER_SEEK_CONFIG?: { fps: number; fpsSource: string };
+      }
+    ).__HF_EXPORT_RENDER_SEEK_CONFIG = {
+      fps: 60,
+      fpsSource: "future-source",
+    };
+
+    initSandboxRuntimeModular();
+
+    expect(infoSpy).toHaveBeenCalledWith(
+      "[hyperframes] render runtime fps",
+      expect.objectContaining({
+        canonicalFps: 60,
+        source: "unknown",
+        rawFpsSource: "future-source",
+      }),
+    );
+  });
+
+  it("keeps the default 30fps renderSeek grid when export render fps is absent", () => {
+    const root = document.createElement("div");
+    root.setAttribute("data-composition-id", "main");
+    root.setAttribute("data-root", "true");
+    root.setAttribute("data-start", "0");
+    root.setAttribute("data-duration", "1");
+    root.setAttribute("data-width", "1920");
+    root.setAttribute("data-height", "1080");
+    document.body.appendChild(root);
+
+    const timeline = createMockTimeline(1);
+    window.__timelines = { main: timeline };
+
+    initSandboxRuntimeModular();
+
+    // This is the originally broken 60fps render sample under the historical
+    // 30fps runtime default: floor((1 / 60) * 30) / 30 = 0.
+    window.__player?.renderSeek(1 / 60);
+
+    expect(timeline.time()).toBe(0);
+  });
+
   it("uses live child timeline duration when a composition host has no authored duration", () => {
     const root = document.createElement("div");
     root.setAttribute("data-composition-id", "main");

packages/core/src/runtime/init.ts

@@ -40,8 +40,49 @@ import { swallow } from "./diagnostics";
 const AUTHORED_DURATION_ATTR = "data-hf-authored-duration";
 const AUTHORED_END_ATTR = "data-hf-authored-end";
 
+type ExportRenderFpsResolution = {
+  fps: number | null;
+  source: "render-options" | "default" | "unknown";
+  rawFpsSource: unknown;
+  rawFps: unknown;
+  fallbackReason?: "missing" | "invalid";
+};
+
+function resolveExportRenderFps(): ExportRenderFpsResolution {
+  const config = window.__HF_EXPORT_RENDER_SEEK_CONFIG;
+  const rawFps = config?.fps;
+  const rawFpsSource = config?.fpsSource;
+  const fps = Number(rawFps);
+  if (!config || rawFps == null) {
+    return { fps: null, source: "default", rawFpsSource, rawFps, fallbackReason: "missing" };
+  }
+  if (!Number.isFinite(fps) || fps <= 0) {
+    return { fps: null, source: "default", rawFpsSource, rawFps, fallbackReason: "invalid" };
+  }
+  const source =
+    rawFpsSource === "render-options" || rawFpsSource === "default" ? rawFpsSource : "unknown";
+  return {
+    fps,
+    source,
+    rawFpsSource,
+    rawFps,
+    fallbackReason: config.fpsFallbackReason,
+  };
+}
+
 export function initSandboxRuntimeModular(): void {
   const state = createRuntimeState();
+  const exportRenderFps = resolveExportRenderFps();
+  state.canonicalFps = exportRenderFps.fps ?? state.canonicalFps;
+  if (window.__HF_EXPORT_RENDER_SEEK_CONFIG) {
+    console.info("[hyperframes] render runtime fps", {
+      canonicalFps: state.canonicalFps,
+      source: exportRenderFps.source,
+      rawFpsSource: exportRenderFps.rawFpsSource,
+      rawFps: exportRenderFps.rawFps,
+      fallbackReason: exportRenderFps.fallbackReason,
+    });
+  }
   let colorGradingRuntime: RuntimeColorGradingApi | null = null;
   let runtimeErrorListener: ((event: ErrorEvent) => void) | null = null;
   let runtimeUnhandledRejectionListener: ((event: PromiseRejectionEvent) => void) | null = null;

packages/core/src/runtime/window.d.ts

@@ -39,7 +39,18 @@ declare global {
     __playerReady?: boolean;
     __renderReady?: boolean;
     __hfRuntimeTeardown?: (() => void) | null;
+    __HF_EXPORT_RENDER_SEEK_CONFIG?: {
+      mode?: string;
+      diagnostics?: boolean;
+      step?: number;
+      offsetFraction?: number;
+      fps?: number;
+      fpsSource?: "render-options" | "default";
+      fpsFallbackReason?: "missing" | "invalid";
+      owner?: string;
+    };
     __HF_PARITY_MODE?: boolean;
+    /** Legacy debug-only fps hint. Render-mode runtime fps uses __HF_EXPORT_RENDER_SEEK_CONFIG.fps. */
     __HF_FPS?: number;
     __HF_MAX_DURATION_SEC?: number;
     __hfThreeTime?: number;

packages/engine/src/services/frameCapture.test.ts

@@ -1,6 +1,7 @@
 import { describe, it, expect } from "vitest";
 import {
   formatHttpErrorDiagnostic,
+  formatConsoleDiagnostic,
   formatNavigationFailureDiagnostic,
   formatNavigationStartDiagnostic,
   formatRequestFailureDiagnostic,
@@ -118,6 +119,37 @@ describe("isFontResourceError", () => {
   });
 });
 
+describe("formatConsoleDiagnostic", () => {
+  it("surfaces HyperFrames page logs with a dedicated host prefix", () => {
+    expect(
+      formatConsoleDiagnostic("info", "[hyperframes] render runtime fps JSHandle@object", ""),
+    ).toEqual({
+      text: "[HyperFrames] render runtime fps JSHandle@object",
+      suppressHostLog: false,
+    });
+  });
+
+  it("keeps font load errors in diagnostics but suppresses host log noise", () => {
+    expect(
+      formatConsoleDiagnostic(
+        "error",
+        "Failed to load resource: net::ERR_FAILED",
+        "https://fonts.googleapis.com/css2?family=Inter",
+      ),
+    ).toEqual({
+      text: "[Browser] Failed to load resource: net::ERR_FAILED",
+      suppressHostLog: true,
+    });
+  });
+
+  it("preserves existing browser prefixes for generic logs", () => {
+    expect(formatConsoleDiagnostic("warn", "careful", "")).toEqual({
+      text: "[Browser:WARN] careful",
+      suppressHostLog: false,
+    });
+  });
+});
+
 describe("navigation diagnostics", () => {
   it("redacts credentials, query strings, and fragments from diagnostic URLs", () => {
     expect(

packages/engine/src/services/frameCapture.ts

@@ -506,6 +506,36 @@ export function isFontResourceError(type: string, text: string, locationUrl: str
   );
 }
 
+export function formatConsoleDiagnostic(
+  type: string,
+  text: string,
+  locationUrl: string,
+): { text: string; suppressHostLog: boolean } {
+  const isFontLoadError = isFontResourceError(type, text, locationUrl);
+  if (isFontLoadError) return { text: `[Browser] ${text}`, suppressHostLog: true };
+
+  if (text.startsWith("[hyperframes]")) {
+    return {
+      text: `[HyperFrames] ${text.slice("[hyperframes]".length).trim()}`,
+      suppressHostLog: false,
+    };
+  }
+
+  // Other "Failed to load resource" 404s are typically non-blocking (e.g.
+  // favicon, sourcemaps, optional assets). Prefix them so users know they
+  // are harmless and don't confuse them with real render errors.
+  const isResourceLoadError = type === "error" && text.startsWith("Failed to load resource");
+  const prefix = isResourceLoadError
+    ? "[non-blocking]"
+    : type === "error"
+      ? "[Browser:ERROR]"
+      : type === "warn"
+        ? "[Browser:WARN]"
+        : "[Browser]";
+
+  return { text: `${prefix} ${text}`, suppressHostLog: false };
+}
+
 async function pollPageExpression(
   page: Page,
   expression: string,
@@ -866,32 +896,15 @@ async function waitForOptionalTailwindReady(page: Page, timeoutMs: number): Prom
 export async function initializeSession(session: CaptureSession): Promise<void> {
   const { page, serverUrl } = session;
 
-  // Forward browser console to host with [Browser] prefix
-  // fallow-ignore-next-line complexity
+  // Forward browser console to host. HyperFrames runtime logs get a dedicated
+  // prefix so page-context observability is visible in producer stdout.
   page.on("console", (msg: ConsoleMessage) => {
     const type = msg.type();
     const text = msg.text();
     const locationUrl = msg.location()?.url ?? "";
-    const isFontLoadError = isFontResourceError(type, text, locationUrl);
-
-    // Other "Failed to load resource" 404s are typically non-blocking (e.g.
-    // favicon, sourcemaps, optional assets). Prefix them so users know they
-    // are harmless and don't confuse them with real render errors.
-    const isResourceLoadError =
-      type === "error" && text.startsWith("Failed to load resource") && !isFontLoadError;
-
-    const prefix = isResourceLoadError
-      ? "[non-blocking]"
-      : type === "error"
-        ? "[Browser:ERROR]"
-        : type === "warn"
-          ? "[Browser:WARN]"
-          : "[Browser]";
-    if (!isFontLoadError) {
-      console.log(`${prefix} ${text}`);
-    }
-
-    appendBrowserDiagnostic(session, `${prefix} ${text}`);
+    const diagnostic = formatConsoleDiagnostic(type, text, locationUrl);
+    if (!diagnostic.suppressHostLog) console.log(diagnostic.text);
+    appendBrowserDiagnostic(session, diagnostic.text);
   });
 
   page.on("pageerror", (err) => {

packages/producer/src/services/distributed/renderChunk.ts

@@ -500,6 +500,9 @@ export async function renderChunk(
       compiledDir,
       port: 0,
       preHeadScripts: [buildVirtualTimeShim({ seedRandomFromFrame: true })],
+      // These dimensions are frozen by the controller from the render job, so
+      // chunk runtime seek quantization stays on the same fps grid as capture.
+      fps: { num: plan.dimensions.fpsNum, den: plan.dimensions.fpsDen },
     });
 
     const captureOptions: CaptureOptions = {

packages/producer/src/services/fileServer.test.ts

@@ -226,6 +226,77 @@ describe("isPathInside", () => {
 });
 
 describe("createFileServer", () => {
+  async function expectInjectedRenderFps(
+    fps: Parameters<typeof createFileServer>[0]["fps"],
+    expected: {
+      value: string;
+      source: "render-options" | "default";
+      fallbackReason?: "missing" | "invalid";
+    },
+  ): Promise<void> {
+    const projectDir = mkdtempSync(join(tmpdir(), "hf-file-server-render-fps-"));
+
+    try {
+      writeEmptyIndex(projectDir);
+      const server = await createFileServer({
+        projectDir,
+        preHeadScripts: [],
+        headScripts: [],
+        ...(fps ? { fps } : {}),
+      });
+      try {
+        const response = await fetch(`${server.url}/index.html`);
+        expect(response.status).toBe(200);
+        const html = await response.text();
+        expect(html).toContain("window.__HF_EXPORT_RENDER_SEEK_CONFIG");
+        expect(html).toContain(`var __renderFps = ${expected.value}`);
+        expect(html).toContain(`var __renderFpsSource = "${expected.source}"`);
+        if (expected.fallbackReason) {
+          expect(html).toContain(`var __renderFpsFallbackReason = "${expected.fallbackReason}"`);
+        } else {
+          expect(html).toContain("var __renderFpsFallbackReason = null");
+        }
+        expect(html).toContain("fps: __renderFps");
+        expect(html).toContain("fpsSource: __renderFpsSource");
+        expect(html).not.toContain("[hyperframes] render fps defaulted");
+      } finally {
+        server.close();
+      }
+    } finally {
+      rmSync(projectDir, { recursive: true, force: true });
+    }
+  }
+
+  it("injects the requested render fps into the page render config", async () => {
+    await expectInjectedRenderFps({ num: 60, den: 1 }, { value: "60", source: "render-options" });
+  });
+
+  it("injects fractional render fps without rounding", async () => {
+    await expectInjectedRenderFps(
+      { num: 24000, den: 1001 },
+      { value: "23.976023976023978", source: "render-options" },
+    );
+  });
+
+  it("marks missing render fps as an explicit 30fps default", async () => {
+    await expectInjectedRenderFps(undefined, {
+      value: "30",
+      source: "default",
+      fallbackReason: "missing",
+    });
+  });
+
+  it("marks invalid render fps as an explicit 30fps default", async () => {
+    await expectInjectedRenderFps(
+      { num: 60, den: 0 },
+      {
+        value: "30",
+        source: "default",
+        fallbackReason: "invalid",
+      },
+    );
+  });
+
   it("serves asset files through project-root symlinked directories", async () => {
     const workspaceDir = mkdtempSync(join(tmpdir(), "hf-file-server-symlink-assets-"));
     const adsDir = join(workspaceDir, "Ads");