Scarb metadata command
You can use the scarb metadata command to get information about package structure and dependencies. The format is stable and versioned. When calling scarb metadata, you are required to pass --format-version flag explicitly.
See scarb metadata --help for more information about accepted arguments.
Reading metadata from Rust
If you are using Rust, the scarb-metadata crate can be used to invoke the scarb metadata command appropriately and parse its output.