Common free slot finder API

Finds time slots within a window during which every participant is free, merging each person's busy intervals into a blocked mask and returning the earliest fitting slots. Answers 'When are all N people free for a 30-minute meeting?', 'What's the earliest slot everyone can make?'.

Price$0.03per request

MethodPOST

Route/v1/scheduling/common-free-slot

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

schedulingmeetingscalendaravailabilityfree-slotintervalsagentscoordination

API URLhttps://x402.hexl.dev/v1/scheduling/common-free-slot

Integration docs

Example request

{
  "windowStart": "2026-06-04T09:00:00Z",
  "windowEnd": "2026-06-04T17:00:00Z",
  "durationMinutes": 30,
  "participants": [
    {
      "id": "a",
      "busy": [
        {
          "start": "2026-06-04T09:00:00Z",
          "end": "2026-06-04T10:00:00Z"
        }
      ]
    },
    {
      "id": "b",
      "busy": [
        {
          "start": "2026-06-04T10:00:00Z",
          "end": "2026-06-04T10:30:00Z"
        },
        {
          "start": "2026-06-04T12:00:00Z",
          "end": "2026-06-04T13:00:00Z"
        }
      ]
    }
  ],
  "maxResults": 2
}

Example response

{
  "durationMinutes": 30,
  "participantCount": 2,
  "slots": [
    {
      "start": "2026-06-04T10:30:00.000Z",
      "end": "2026-06-04T11:00:00.000Z"
    },
    {
      "start": "2026-06-04T11:00:00.000Z",
      "end": "2026-06-04T11:30:00.000Z"
    }
  ],
  "found": true,
  "earliest": {
    "start": "2026-06-04T10:30:00.000Z",
    "end": "2026-06-04T11:00:00.000Z"
  },
  "blockedIntervals": [
    {
      "start": "2026-06-04T09:00:00.000Z",
      "end": "2026-06-04T10:30:00.000Z"
    },
    {
      "start": "2026-06-04T12:00:00.000Z",
      "end": "2026-06-04T13:00:00.000Z"
    }
  ],
  "interpretation": "2 common free slot(s); earliest starts 2026-06-04T10:30:00.000Z."
}

Input schema

{
  "type": "object",
  "required": [
    "windowStart",
    "windowEnd",
    "durationMinutes",
    "participants"
  ],
  "properties": {
    "windowStart": {
      "type": "string",
      "description": "ISO 8601 start of search window",
      "examples": [
        "2026-06-04T09:00:00Z"
      ]
    },
    "windowEnd": {
      "type": "string",
      "examples": [
        "2026-06-04T17:00:00Z"
      ]
    },
    "durationMinutes": {
      "type": "number",
      "examples": [
        30
      ]
    },
    "participants": {
      "type": "array",
      "items": {
        "type": "object"
      }
    },
    "granularityMinutes": {
      "type": "number",
      "examples": [
        30
      ]
    },
    "maxResults": {
      "type": "number",
      "examples": [
        5
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}