Context Type

The context channel carries structured metadata alongside your data. It is represented by ContextType and is part of every Payload.

In user code, you rarely manipulate the context directly - pipeline nodes and observers usually do this for you. However, it is useful to understand how the context behaves.

Creating and using a context

from semantiva import ContextType

ctx = ContextType()

# Store values
ctx.set_value("threshold", 0.5)
ctx.set_value("run.label", "demo")

# Retrieve them
print("threshold:", ctx.get_value("threshold"))
print("label:", ctx.get_value("run.label"))

threshold: 0.5
label: demo

Context values are used for:

  • Parameters injected into operations (for example an addend or a path).

  • Metrics and probe results stored during execution.

  • Flags or small pieces of state that guide downstream behaviour.

Context and payload

The context always travels together with the data inside a Payload:

from semantiva import Payload

payload = Payload(data="example", context=ctx)
print(payload.data)
print(payload.context.get_value("threshold"))

example
0.5

Important invariant

User-defined components (data operations, data probes, context processors) do not receive ContextType directly in their business logic. They see parameters, and nodes/observers perform the actual context updates.

Next steps