You need a token for it to work. To get a trial token, you can get one at https://dash.slingdata.io. Once you have it, put the value in an environment variable called SLING_CLI_TOKEN. That's it, Sling will validate your token when you run it and the Pro features will be enabled.

Each CLI Pro subscription includes 2 tokens: a production token for your production environment and a development token for testing. We recommend purchasing one subscription per team or workload. This allows you to use the production token across your production environments (whether permanent servers or containers) while sharing the development token among team members. For example, if you have separate data engineering and analytics teams, each team would need their own subscription. See here for more details.

Hooks are customizable actions that can be triggered before or after a replication stream. They enable you to extend pipeline functionality with operations like data validation, notifications, or custom API calls. Common hook types include query execution, data checks, notifications, and HTTP webhooks. See here for more details.

Parallel streams allow you to process multiple data streams simultaneously, significantly improving performance. For example, when replicating multiple tables or processing large files, parallel streams can dramatically reduce the total processing time by utilizing available system resources more efficiently. See here for more details.