Telegraf - Is it free or need to be paid?

I learn that Telegraf is opensource. For commercial use , does user need to pay ( similar to InfluxDB)

Telegraf is available to use free of charge. The binaries and source code are available at GitHub - influxdata/telegraf: The plugin-driven server agent for collecting & reporting metrics.. For legal details, see the license file (telegraf/LICENSE at master · influxdata/telegraf · GitHub)