Stackfuse Email Maker

This project is now a webhook-driven Telegram bot for Cloudflare Workers.

What the bot actually does

The original bot had one core job:

1. Accept rough outbound-email notes in Telegram.
2. Extract TO: if present, and otherwise let OpenAI infer a recipient email when the text includes one.
3. Ask OpenAI to reshape the notes into a structured JSON object that fits the Stackfuse email template.
4. Render that JSON into a fixed dark HTML template.
5. Build a multipart .eml draft with both plain-text and HTML parts.
6. Send that .eml back to the Telegram user as stackfuse-email.eml.

The Cloudflare rewrite preserves that flow, but changes the runtime model:

• No polling process.
• No Python runtime.
• No local lock files.
• Telegram now delivers updates to a Worker webhook.
• The Worker returns 200 immediately and finishes the email generation in background work.

Current architecture

• src/worker.mjs: Cloudflare Worker entrypoint and all runtime logic.
• wrangler.jsonc: Worker configuration.
• tests/worker.test.mjs: smoke tests for parsing, templating, and .eml generation.

Runtime behavior

• GET /: status payload describing the service.
• GET /health: lightweight health check.
• POST /webhook/telegram: Telegram webhook endpoint protected by X-Telegram-Bot-Api-Secret-Token.

Supported Telegram interactions:

• /start: explains how to use the bot.
• Plain text message: generates and returns an .eml draft.

Not carried over:

• The old optional Send now flow. The previous implementation relied on SMTP or Gmail OAuth from a long-running Python process. That is not portable to Cloudflare Workers without a different mail-delivery integration.

Required secrets

Configure these in Cloudflare as Worker secrets:

• OPENAI_API_KEY
• TELEGRAM_BOT_TOKEN
• TELEGRAM_WEBHOOK_SECRET

Optional plain-text vars:

• OPENAI_MODEL
• DEFAULT_FROM

For local development, copy .dev.vars.example to .dev.vars.

Local verification

node --test

Deployment notes

The Worker is intended to run on workers.dev and receive Telegram webhooks directly. After deployment, Telegram should point to:

https://<worker-name>.<workers-subdomain>.workers.dev/webhook/telegram

with the configured secret token.

Sources used for the rewrite

• Cloudflare Workers best practices
• Cloudflare Wrangler docs
• Telegram Bot API: setWebhook
• OpenAI migration guide for Responses and structured output changes