Yes, the Connector Builder is available in the open-source version of Airbyte. The [Connector Builder UI](https://docs.airbyte.com/connector-development/connector-builder-ui/overview) allows you to develop and use connectors without leaving the Airbyte UI, and it doesn't require a local development environment. This feature is based on the low-code development framework and helps you build source connectors for REST APIs by modifying boilerplate YAML files.