Developers
Anything your staff can do in the diary, your tools can do through the API, with the same rules, permissions and audit trail.
Versioned JSON over HTTPS at https://book.scalingfirm.com/api/v1. Money is in minor units, times are ISO 8601 with offsets, and every change accepts an idempotency key so retries never double book.
curl https://book.scalingfirm.com/api/v1/availability \
-H "Authorization: Bearer $SFB_KEY" \
-G -d service_id=<service-id> -d date=2026-10-16Point Claude or any other MCP client at https://book.scalingfirm.com/mcp with a scoped key. Tools include search_availability, create_booking_hold, create_deposit_request, reschedule_booking, get_cancellation_preview, cancel_booking and request_human_handover.
{ "mcpServers": { "booking": {
"url": "https://book.scalingfirm.com/mcp",
"headers": { "Authorization": "Bearer $SFB_KEY" } } } }Subscribe to booking, payment and message events. Each delivery is signed, retried with backoff and carries a correlation id you can trace through the audit trail.
Create a key per tool with only the scopes it needs. Refunds and bulk changes can wait for a person to approve them. Revoke a key and it stops at once.
Build your own booking widget on /api/v1/public/{business}: services, practitioners, availability, holds, deposits and self-service changes, without a key.
Voice receptionists and chat assistants check real availability, hold the slot while the caller decides and send the deposit link. Anything unclear goes to your inbox with the conversation attached.
7 days free
Set up your services and team, share your booking link and take your first deposit. 7 days free. Cancel any time.