pipe.output_multiplicity

A pipe's output does not have the declared multiplicity


Type	`https://mthds.ai/errors/pipe.output_multiplicity`
Family	`pipe`: A pipe failing at run time because of what the method does.
Domain	`method`: the method's author acts, by changing the method
Retry	`no`: repeating the operation fails the same way
HTTP status	`422`
Raised as	a problem document, sent as the body of an HTTP response or kept in a run's record

What it means

At run time a pipe produced a list where its output is declared as a single item, or the reverse. Validation catches what it can before any run as method.output_multiplicity_mismatch; this code is what a run finds.

What to do

Declare the output with the multiplicity the pipe produces, or change the pipe so that it produces the declared one, such as by telling a PipeLLM how many items to give.

Next steps

A problem carries the step aimed at whoever reads it: the first when its reader is the domain's actor, the method's author, and the second for any other reader.

Reader	Kind	Detail
The domain's actor	`change_method`	Declare the output '`{output}`' as '`{produced}`', or make pipe '`{pipe}`' produce '`{declared}`'.
Any other reader	`contact_owner`	Ask the method's owner to make the output '`{output}`' of pipe '`{pipe}`' match its declared multiplicity.

Detail

The problem's detail is written from this template, filled with the occurrence's parameters:

Pipe '{pipe}' produced an output of the multiplicity '{produced}', but its output '{output}' is declared '{declared}'.

Parameters

Every parameter is present on every occurrence of the code.

Name	Type	Description
`pipe`	`identifier`	The pipe at fault.
`output`	`identifier`	The output whose multiplicity differs.
`declared`	one of `single`, `list`	The multiplicity the method declares.
`produced`	one of `single`, `list`	The multiplicity the pipe produced.