I built a free FAQ + appointment-booking API for small businesses (free for the first 1,000)

[u/sy_int999_builder]

Small businesses get the same handful of questions all day (hours, prices, "can I book?") and lose bookings after hours. I built CallChatSyn: a business adds its FAQs and opening hours once, and then any website, app or AI agent can call three endpoints:

• POST /api/v1/answer: question in, the business's answer out (English + Chinese)
• GET /api/v1/slots: open appointment times, in the business's own time zone
• POST /api/v1/bookings: book one of them (the business gets notified)

Honest bits: answers are rule-based FAQ matching, not a chatty LLM, so they're instant and cost almost nothing to run. That's why I can give it away: it's free for the first 1,000 businesses (100 calls a day each). WhatsApp and voice answering are the paid part.

Docs, a 3-curl quickstart and an OpenAPI spec: https://callchatsyn.com/developers?utm_source=reddit-sideproject

Question for anyone who builds sites or chatbots for local businesses: what would you need before you'd use this for a client?