{"slug": "show-hn-a-free-faq-and-appointment-booking-api-for-small-businesses", "title": "Show HN: A free FAQ and appointment booking API for small businesses", "summary": "CallChatSyn launched a free public API that lets small businesses expose their answering bot, order status and booking calendar to websites, apps and AI agents, with founder access free for the first 1,000 businesses at up to 100 API calls a day and 2,000 a month. The API is documented with an OpenAPI spec and a public demo key, ccs_demo_public, that allows 500 calls a day in total and returns dry-run bookings, and an open-source MCP server, callchatsyn-mcp, gives Claude, Cursor and other MCP clients three tools for answering questions, listing open times and booking appointments.", "body_md": "# CallChatSyn API\n\nUse your business's CallChatSyn answering bot and booking calendar from your own website, app or AI agent. Same answers your customers get on WhatsApp and your booking page. Machine-readable spec: [openapi.json](https://callchatsyn.com/openapi.json).\n\nFounder offer: free for the first 1,000 businesses\n\nAnswering bot, order status and bookings through the API on any plan, with no trial expiry (up to 100 API calls a day, 2,000 a month). Building for clients? Each client business claims its own spot.\n\n1. Create a free account and confirm your email.\n2. Add your FAQs and opening hours (2 minutes).\n3. Open Dashboard → Developers, click *Claim founder API access* , and create a key.\n\n## Try it now, no sign-up\n\nUse the public demo key `ccs_demo_public` with any example below. It answers as our demo business, and bookings are dry runs: you see the time would be booked, but nothing is saved. It's shared by everyone, so it allows 500 calls a day in total.\n\n```\ncurl https://callchatsyn.com/api/v1/answer \\\n  -H \"Authorization: Bearer ccs_demo_public\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\"message\": \"Where are you located?\"}'\n```\n\n## 1. Get a key\n\nIn [Dashboard → Developers](https://callchatsyn.com/dashboard/developers), create a key. It's shown once; keep it on your server, never in browser code. Send it on every request as `Authorization: Bearer ccs_live_…`.\n\n## 2. Answer a customer's message\n\n```\ncurl https://callchatsyn.com/api/v1/answer \\\n  -H \"Authorization: Bearer $CCS_KEY\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\"message\": \"What are your opening hours?\"}'\n\n# {\"intent\":\"faq\",\"lang\":\"en\",\"matched\":true,\"reply\":\"We're open every day, 9am to 9pm.\"}\n```\n\n## 3. Book an appointment\n\n```\ncurl https://callchatsyn.com/api/v1/slots -H \"Authorization: Bearer $CCS_KEY\"\n# {\"slots\":[{\"start\":\"2026-10-10T02:00:00.000Z\",\"label\":\"Sat 10 Oct, 10:00\"}],\"services\":[\"Haircut\"],\"locations\":[\"Main St\"]}\n\ncurl https://callchatsyn.com/api/v1/bookings \\\n  -H \"Authorization: Bearer $CCS_KEY\" -H \"Content-Type: application/json\" \\\n  -d '{\"start\":\"2026-10-10T02:00:00.000Z\",\"service\":\"Haircut\",\"name\":\"Ana\",\"email\":\"ana@example.com\"}'\n\n# 201 {\"booked\":true,\"start\":\"2026-10-10T02:00:00.000Z\",\"label\":\"Sat 10 Oct, 10:00\"}\n```\n\n## Use it from an AI assistant (MCP)\n\nThe open-source [callchatsyn-mcp](https://github.com/oneappsworld/callchatsyn-mcp) server gives Claude, Cursor and other MCP clients three tools: answer a customer question, list open times, book an appointment.\n\n```\n{\n  \"mcpServers\": {\n    \"callchatsyn\": {\n      \"command\": \"npx\",\n      \"args\": [\"-y\", \"github:oneappsworld/callchatsyn-mcp\"],\n      \"env\": { \"CALLCHATSYN_API_KEY\": \"ccs_live_...\" }\n    }\n  }\n}\n```\n\n## Errors and limits\n\n- Errors look like `{\"error\":{\"code\":\"…\",\"message\":\"…\"}}` .\n- With the demo key, `POST /api/v1/bookings` returns 200 with`{\"booked\":false,\"demo\":true}` instead of booking.\n- 401 bad key · 402 plan inactive · 403 feature not in plan · 429 usage limit · 400/404/409 request problems.\n- Each request counts toward the business's plan limits, the same as WhatsApp and booking-page messages.\n- The answering bot, order status and bookings are included on the Pro plan. **Founder offer:** the first 1,000 businesses to claim it in Dashboard → Developers get them free on any plan (up to 100 API calls a day, 2,000 a month).", "url": "https://wpnews.pro/news/show-hn-a-free-faq-and-appointment-booking-api-for-small-businesses", "canonical_source": "https://callchatsyn.com/developers", "published_at": "2026-10-04 01:57:42+00:00", "updated_at": "2026-10-04 02:06:36.038933+00:00", "lang": "en", "topics": ["ai-agents", "agent-protocols", "ai-tools", "ai-products"], "entities": ["CallChatSyn", "callchatsyn-mcp", "Claude", "Cursor", "oneappsworld"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/show-hn-a-free-faq-and-appointment-booking-api-for-small-businesses", "markdown": "https://wpnews.pro/news/show-hn-a-free-faq-and-appointment-booking-api-for-small-businesses.md", "text": "https://wpnews.pro/news/show-hn-a-free-faq-and-appointment-booking-api-for-small-businesses.txt", "jsonld": "https://wpnews.pro/news/show-hn-a-free-faq-and-appointment-booking-api-for-small-businesses.jsonld"}}