Automating Audio Narration with Sanity Blueprints and Google Text-to-Speech
I recently developed an automated audio narration pipeline for my blog using Sanity, Next.js, and Google Cloud Text-to-Speech. The system regenerates a high-quality MP3 narration automatically whenever the blog post content changes, avoiding manual steps, wasted API calls, or infinite loops. The process relies on Sanity's native automation tools, including Blueprints, delta detection, and GROQ projections. The system reacts to content changes at the CMS level, triggering narration generation only when the blog post's body field changes. This is achieved by using Sanity's delta function to detect changes and a secure webhook to initiate the narration generation via a Next.js API route. The generated MP3 is uploaded back to Sanity and linked to the post. This ensures narration is generated only once per meaningful content change. Storing the audio in Sanity is effective for a personal blog, as it utilizes Sanity's CDN, keeps editorial state and content in one place, and eliminates the need for extra storage services. The result is a fully automated, content-driven audio system with no manual triggers, unnecessary TTS calls, or client-side secrets, providing a clean separation of concerns and scalability.
