Generate two-host PDF podcasts with GPT-5, Smallest AI, and Gmail

Description

Generate two-host AI podcast episodes from any PDF — in 9 Indian languages or your own cloned voice — powered by Smallest AI.

Turn whitepapers, research reports, blog drafts, lecture notes, or company memos into NotebookLM-style audio briefings. Native Hindi, Tamil, Telugu, Kannada, Malayalam, Bengali, Marathi, Gujarati, and Punjabi support makes this the only n8n template that ships authentic Indian-language podcast generation out of the box.

Good to know

Lightning V3.1 generates ~100ms time-to-first-byte; a 5-page PDF produces a 4-minute podcast in roughly 60 seconds total
Smallest AI offers a free tier — get an API key
Voice cloning lets you cast yourself or a colleague as one of the hosts using just a 10-second voice sample
Pure JavaScript audio concatenation — no FFmpeg required, works on n8n Cloud

How it works

Upload a PDF via the form trigger
Extract text and pass it to GPT-5 to generate a structured 2-host script in JSON
Split the script and route each turn to the matching host's TTS branch
Smallest AI Lightning synthesizes each turn at 24 kHz with sub-100ms latency
A Code node concatenates all WAV chunks into a single audio file in correct conversational order
The finished podcast is emailed to the address you specify

Set up steps

Install the n8n-nodes-smallestai community node via Settings → Community Nodes
Connect Smallest AI, OpenAI, and Gmail credentials (~5 minutes)
Pick voice IDs for Host A and Host B in the two Synthesize Host nodes (defaults: avery and devansh)
Update the recipient email in the Gmail node
Sticky notes inside the workflow walk you through each section

Requirements

Smallest AI** account — free tier available at smallest.ai
OpenAI** API key — GPT-5 or GPT-4o-mini both work
Gmail** OAuth2 credential for delivery
n8n-nodes-smallestai** community node installed

Customising this workflow

Swap the Form trigger for a Webhook to integrate with other apps or chatbots
Change the LLM system prompt to alter podcast format (interview, debate, monologue, kids' story)
Edit english in the prompt to generate podcasts in any of Smallest AI's supported languages — try arjun + aanya for Hindi, arvind + niharika for Tamil
Use cloned voices from the Voice Clone resource for personalized hosts
Replace Gmail with Slack, Telegram, or Drive Upload for different delivery channels