Bulk upload with nodeJs | ThingSpeak API | Forum

This works for me:

async function bulkUpdate(url, bulkJson) {
const response = await fetch(url, {
method: 'post',
body: JSON.stringify(bulkJson),
headers: {
'Content-Type': 'application/json'
},
});
console.log(response);
}

This function can be called like this:

url = 'https://api.thingspeak.com/channels/' + channel + '/bulk_update.json';
bulkUpdate(url, bulkJson);

In the above, 'channel' is your ThingSpeak channel number. 'bulkJson' is the object that contains the bulk update information:

let bulkJson = {
write_api_key: ''...your write key goes here..."
updates: []
};

Each entry in the bulkJson.updates array is something like this:

bulkJson.updates.push({
created_at: timestamp,
field1: value
})

I hope this helps. I was struggling with this for a while until I included

headers: {
'Content-Type': 'application/json'
},

as described above.