From dc4671dee6f5b28df955c07a99efa68b014d1b7d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miguel=20=C3=81ngel?= <miguel.sierra@heygen.com>
Date: Wed, 27 May 2026 20:20:21 -0400
Subject: [PATCH] fix(studio): add FFmpeg pre-flight check before render
 (#1100)
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* fix(studio): add FFmpeg pre-flight check before starting render

Studio renders now fail fast with a 422 and an actionable FFmpeg
install hint instead of burning through the entire capture pipeline
before hitting "spawn ffmpeg ENOENT" at encode.

* fix(studio): address review — use 503, memoize FFmpeg lookup
---
 packages/cli/src/server/studioServer.ts | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/packages/cli/src/server/studioServer.ts b/packages/cli/src/server/studioServer.ts
index 5e415f9ab..8c7ae9b0c 100644
--- a/packages/cli/src/server/studioServer.ts
+++ b/packages/cli/src/server/studioServer.ts
@@ -508,6 +508,22 @@ export function createStudioServer(options: StudioServerOptions): StudioServer {
     });
   });
 
+  // ── Pre-flight checks for render ────────────────────────────────────────
+  // Intercept render requests before they reach the shared API so we can
+  // fail fast with an actionable hint instead of burning through the entire
+  // capture pipeline before hitting "spawn ffmpeg ENOENT" at encode.
+  let cachedFFmpegPath: string | undefined;
+  app.post("/api/projects/:id/render", async (c, next) => {
+    const { findFFmpeg, getFFmpegInstallHint } = await import("../browser/ffmpeg.js");
+    if (!cachedFFmpegPath) {
+      cachedFFmpegPath = findFFmpeg();
+    }
+    if (!cachedFFmpegPath) {
+      return c.json({ error: "FFmpeg not found", hint: getFFmpegInstallHint() }, 503);
+    }
+    return next();
+  });
+
   // Mount the shared studio API at /api.
   // Use fetch() forwarding (not .route()) so the sub-app sees paths without
   // the /api prefix — the shared module's path extraction uses c.req.path.