i'm using Netlify serverless functions.

when I run JSON.parse on the event.body response I get SyntaxError: Unexpected end of JSON input

My client side code is as follows:

const items = [{ id: 'prod_LvqkrsI9O5F0xJ' }];

async function initialize() {
    const response = await fetch('/.netlify/functions/createPaymentIntent', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ items }),
    });
    console.log(response);
    const { clientSecret } = await response.json();

Server side code is as follows:

exports.handler = async (event, context) => {
    const items = await JSON.parse(event.body);
    console.log('items', items);

the console logs out

items { items: [ { id: 'prod_LvqkrsI9O5F0xJ' } ] }
...{"level":"error","message":"End - Error:"}
{"errorMessage":"Unexpected end of JSON input","errorType":"SyntaxError","level":"error",...

Any ideas please?