Recurring Date (RRULE-lite) Expander

Expand a bounded recurrence rule (FREQ/INTERVAL/COUNT/UNTIL/BYDAY) into concrete occurrence datetimes.

Free tier eligible — 500 calls/month with a free key from /pricing; x402 pay-per-call above quota.

Parameters

Parameter	Type	Required	Description
`dtstart`	string	required	Start datetime, ISO 8601
`freq`	string	required	DAILY \| WEEKLY \| MONTHLY \| YEARLY One of: DAILY, WEEKLY, MONTHLY, YEARLY
`interval`	integer	optional	Repeat every N freq-units (default 1)
`count`	integer	optional	Number of occurrences to return (default 10, max 200)
`until`	string	optional	Stop generating after this ISO 8601 datetime
`byday`	array	optional	Weekly only: list of weekday codes, e.g. ['MO','WE','FR']

Call it over MCP (JSON-RPC 2.0)

curl -s https://wingmanprotocol.com/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "rrule_expand", "arguments": {"dtstart": "example", "freq": "DAILY"}}}'

Or plain HTTP

curl -s https://wingmanprotocol.com/tools/rrule_expand \
  -H 'Content-Type: application/json' \
  -d '{"dtstart": "example", "freq": "DAILY"}'

Try it live

Edit the JSON and run it — this POSTs to https://wingmanprotocol.com/tools/rrule_expand from your browser.

This tool is x402-metered — agents pay per call with USDC on Base. The 402 response below is the standard x402 payment-requirements envelope: sign the EIP-3009 authorization and retry with the X-Payment header, or get a free key at /pricing (500 calls/month, no card, no crypto).