Debug DSH Web Plugin Runtime Behavior

External Web plugins call host client APIs whose contracts live in the DSH source tree, not in the plugin's own types. When behavior diverges from intent at runtime, the failure is almost always a misread contract — and the diagnosis must come from the host source, never from the API's name.

The standing rule: read the verb's contract in the host source first

Before changing any call into a host API, open the implementing package in the DSH source checkout (~/.dsh/source/current, or the vendored copy) and read the actual method — its doc comment, its guards, and the types it compares against. Repeat for every value the plugin passes. Three questions cover most incidents: