Get metadata value
Extracts a metadata key and refines its type so the value can be used by typed bindings.
Metadata + key
Get metadata value
Lecture stricte
Typed value
Vue d’ensemble
The metadata map accepts several scalar types. get_metadata_value makes the type choice explicit so a process does not propagate a free-form value where an email, amount, or date is expected.
Exemple
Read customer_reference as a string or callback_url as common.url before sending the value to a node whose contract requires that type.
Parameters 3
metadata
common.metadata map containing the key to read.key
Exact key to extract from the metadata map.
expected_type
Expected scalar type for the value. The node validates the existing value; it does not silently convert an incompatible value.
Outputs 1
value
Value of the key with the type selected by
expected_type, after strict validation.Behavior
Read the key
The node requires the key to exist in the map.
Validate the type
The value is checked against expected_type without implicit coercion.
Refine the binding
The output adopts the selected type for downstream validation and suggestions.
Limits and responsibilities
- A missing key causes the node to fail; there is no implicit fallback value.
- A value incompatible with
expected_typeis rejected rather than converted. - For multiple keys, use several explicit reads or prefer a real business object if the contract becomes structured.