Developer Tools

oso offers several developer tools to make it easier to write and understand policies.


The oso REPL lets you query an oso knowledge base interactively, which can be helpful when learning Polar, and during development and debugging.

Read on to see how to use the oso REPL.


The Polar debugger is for debugging policies.

Read on to see how to use the debugger.


Polar debug tracing can be turned on to see logs while queries are evaluated.

Read on to see how to enable tracing.

IDE Support

oso integrations for integrated development environments (IDEs) provide syntax highlighting for .polar files.

Read on to see oso support for IDEs.