idBuf.length;
            if (payloadBytes > 127) throw 'this example currently does not support requests payload longer than 127 bytes - open a PR!';

            let buf = new Uint8Array([
                0,
                'wasi:keyvalue/store@0.2.0-draft2'.length,
                ...text.encode('wasi:keyvalue/store@0.2.0-draft2'),
                'open'.length,
                ...text.encode('open'),
                0,
                payloadBytes,
                idBuf.length,
                ...idBuf
