JSTask file example https://datatracker.ietf.org/doc/draft-ietf-jmap-tasks/

jstask.json

{
    "@type" : "Task",
    "uid" : "0191cadf-f606-40d3-93a5-6b6422d18da8",
    "relatedTo": {
        "9f160501-da22-4a96-a4e9-c56cef8158e8": {
            "@type": "Relation",
            "relation": "depends-on"
        }
    },
    "prodId": "-//OXP apiserver//v1.1.2",
    "created" : "2016-07-14T03:22:56Z",
    "updated" : "2016-08-02T23:08:24Z",
    "sequence" : 0,
    "title": "Add support for JSTask",
    "description" : "JSTask is so great we should try to add it to our product ASAP.",
    "locations" : {
        "start": {
            "name": "Home",
            "rel": "start",
            "timeZone": "Europe/London",
            "address": {
                "street": "1 Primrose Lane",
                "locality": "Tickleton",
                "region": "Gritonshire",
                "postcode": "GT3 7AH",
                "country": "United Kingdom"
            },
            "coordinates": "geo:..."
        },
        "end": {
            "name" : "Neverland",
            "accessInstructions": "Second star to the right, and straight on till morning. Access code is 1234.",
            "rel": "end",
            "timeZone": "Australia/Sydney"
        }
    },
    "links":{
        "c5c3da24-689b-44b1-9bc3-9fedd813cfcd":{
            "title":"2020-11-30 OpenXPort Architecture for exchanging PIM data.pdf",
            "href":"https://www.audriga.com/w/skins/Audriga/resources/img/audriga_220x48px-white.svg",
            "@type":"Link",
            "rel":"enclosure",
            "size":3048,
            "contentType":"application/pdf"
        }
    },
    "keywords" : {
        "Foo": true
    },
    "recurrenceRule" : {
        "@type" : "RecurrenceRule",
        "firstDayOfWeek" : "mo",
        "frequency" : "weekly",
        "interval" : 1,
        "rscale" : "gregorian",
        "skip" : "omit"
    },
    "recurrenceOverrides" : {
        "2016-09-19T09:00:00" : {
            "start" : "2016-09-28T10:00:00"
        },
        "2016-09-26T09:00:00" : null
    },
    "priority" : 0,
    "privacy": "secret",
    "participants" : {
        "neil@example.com" : {
            "email" : "neil@example.com",
            "kind" : "individual",
            "name" : "Neil J",
            "roles" : [
                "owner",
                "assignee"
            ],
            "scheduleStatus" : "accepted",
            "scheduleUpdated" : "2016-05-07T07:08:08Z"
        },
        "diana@example.com" : {
            "email" : "diana@example.com",
            "kind" : "individual",
            "name" : "Diana H",
            "roles" : [
                "assignee"
            ],
            "scheduleStatus" : "accepted",
            "scheduleUpdated" : "2016-05-07T07:33:08Z"
        }
    },
    "alerts": {
        "596EF954-520D-4C36-8141-53ECE91F04CB": {
            "offset" : "PT15H",
            "relativeTo" : "before-start",
            "action": {
                "type" : "display",
                "acknowledged": "2016-08-02T23:08:24Z"
            }
        }
    },
    "timeZone" : "Etc/UTC",
    "due" : "2018-01-08T09:00:00Z",
    "start" : "2018-01-05T09:00:00Z",
    "estimatedDuration" : "PT1H",
    "percentComplete" : 10,
    "progress": "completed",
    "progressUpdated": "2020-11-23T13:26:22Z",
    "audriga.eu:thisIsINiceExampleForAVendorSpecificExtension" : true,
    "audriga.eu:vendorExtensionsWereXPropertiesBefore" : true
},
{
    "@type": "Task",
    "uid" : "9f160501-da22-4a96-a4e9-c56cef8158e8",
    "updated" : "2016-09-13T12:16:00Z",
    "title" : "Simple Task"
}