Talk to Krishna
A live, spoken, interruptible conversation with Krishna as a compassionate counsellor, grounded in
the Bhagavad Gita, the stories of his life and his other teachings.
Next.js 16 · Supabase (login, transcripts, quota) · fal (Grok Voice realtime) · Vercel.
How it fits together
- Browser ↔ fal holds the voice WebSocket, authorised by a 120-second token from
/api/fal/realtime-token (login and daily quota are checked there).
- Scripture search is a function tool: Grok calls
search_scriptures, the browser answers from
/api/search, a BM25 index over data/corpus.json (3,982 English passages built from
../01-bhagavad-gita, ../02-life-stories, ../03-other-teachings by npm run build:corpus).
- Supabase holds accounts, each user's transcripts (row-level security) and minutes used.
Local development
npm run dev serves http://localhost:3456. With only FAL_KEY in .env.local the app runs in
try mode: no login, nothing saved. Add the Supabase variables to run the full app.
Deploying
- Supabase: create a project, then in SQL Editor run
supabase/migrations/20260928000000_init.sql, then supabase/migrations/20261027000000_login.sql
(email and password login: conversations belong to the signed-in user).
- Supabase → Authentication → URL Configuration: Site URL
https://<your-domain>; redirect URLs
https://<your-domain>/auth/callback and http://localhost:3456/auth/callback.
- Vercel → Settings → Environment Variables (from
.env.example): FAL_KEY,
NEXT_PUBLIC_SUPABASE_URL, NEXT_PUBLIC_SUPABASE_ANON_KEY (Supabase → Project Settings → API),
KRISHNA_VOICE, DAILY_MINUTES_LIMIT. Then redeploy.
- Set a monthly spend limit in the fal dashboard, and a Vercel Firewall rate limit on
/api/fal/realtime-token.
If a deploy is missing variables, every page answers 503 naming the ones to add.
Notes from building it
- fal's realtime client holds only one pending message while connecting, so the mic stays muted
until
session.updated; persona, voice and turn detection go on fal's x-fal-session.configure
event, and tools and transcription on a native session.update.
- fal drops the socket on large client messages (~6 KB failed, ~2 KB works), so search results sent
to Grok are trimmed to three passages.
- In dev, each new Grok event type is logged once as
[grok event].
