This is a submission for the Hacktoberfest Weekend Challenge: Build for a Friend
What I Built
I built Kritika for my friend Ananya, who launched a handcrafted candle studio in Bengaluru ahead of the Diwali festive rush.
As order volume grew across social channels, manual order handling became a bottleneck:
- Customers routinely sent 30-to-60-second voice notes on Telegram in mixed English and Hindi requesting custom candle gift sets and local delivery timelines.
- Ananya spent upwards of 4 hours each evening listening to audio clips, checking inventory levels, calculating shipping fees, and manually recording customer addresses into spreadsheets.
Kritika is a lightweight, open-source order desk integrated directly into Telegram. It automates customer communication and back-office order logging by:
- Ingesting incoming Telegram audio voice notes and text messages.
- Transcribing regional speech into clean text.
- Extracting structured order metadata (items, quantities, delivery address, preferred dates).
- Calculating totals, verifying stock availability, and sending instant confirmation summaries back to the user.
How I Built It
The architecture relies entirely on open-weight models, open-source audio tooling, and free-tier infrastructure. The system is designed to run efficiently inside a single Docker container deployed on Render.
+-------------------------------------------------------+
| Customer on Telegram |
| (Sends Voice Message or Text) |
+---------------------------+---------------------------+
|
v
+-------------------------------------------------------+
| Python FastAPI Engine (Render) |
+-------+-------------------+-------------------+-------+
| | |
v v v
+-----------------+ +---------------+ +-------------------+
| Speech Parser | | Open LLM | | Catalog & Order |
| Faster-Whisper | | Gemma 2 | | Database |
| & Edge-TTS | | (Ollama/Groq) | | MongoDB Atlas |
+-----------------+ +---------------+ +-------------------+
Technical Implementation Details:
-
Telegram Webhook Layer (
python-telegram-bot): Captures incoming audio files (.ogg) and text payloads, routing them through asynchronous processing queues. -
Open Audio Pipeline (Faster-Whisper & Edge-TTS):
- Transcribes incoming customer voice messages locally without relying on paid speech-to-text APIs.
- Synthesizes audio responses when customers request spoken status updates.
-
Language Intelligence (Google Gemma 2):
- Parses unstructured customer conversations into strict JSON schemas.
- Handles multi-turn inquiries, stock validation, and shipping address verification.
-
Data Persistence (MongoDB Atlas):
- Maintains product catalog records, stock counts, customer conversation histories, and structured order entries.
-
Observability & Hosting (Render & Sentry):
- Deployed on Render's web service architecture.
- Monitored via Sentry Agent Tracing to measure end-to-end voice processing latency and function execution stability.
Why Does Open Innovation Matter?
- Zero Marginal Operational Cost: Small independent creators operate on thin margins. Using open-weight language models and open speech engines eliminates per-token and per-minute transcription costs, allowing automated order desks to run affordably at scale.
- Accurate Context & Local Speech Adaptation: Proprietary global APIs often fail when transcribing regional accents, local neighborhood landmarks, or mixed-language queries. Open models allow tailored system prompts and localized fine-tuning.
- Data Control & Independence: All customer information, contact details, and order transactions remain strictly within open-source databases under the owner's direct control, preventing unauthorized data processing by commercial API vendors.
Prize Categories
- Best Use of Gemma: Uses Google Gemma 2 as the primary intelligence engine for intent classification, JSON extraction, and conversational responses.
- Best Use of Render: Hosts the complete FastAPI engine, Telegram webhook worker, and order pipeline on Render.
- Best Use of MongoDB Atlas: Manages inventory catalogs, vector-based product queries, and structured customer order states.
- Best Use of Sentry Agent Tracing: Tracks voice transcription latency, tool execution pipelines, and error rates across processing workflows.
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