Lambda Durable Functions require a qualified ARN for invocation

Tried invoking a Durable Function with a plain function name and got an immediate error.

Output

An error occurred (InvalidParameterValueException) when calling the Invoke operation: You cannot invoke a durable function using an unqualified ARN.

You need a version qualifier like fn-Fraud-Detection:$LATEST, or a version number from publish-version.

Terminal

# Correct (escape $LATEST)
aws lambda invoke --function-name "fn-Fraud-Detection:\$LATEST" ...
 
# Wrong ($LATEST expands to empty string in double quotes)
aws lambda invoke --function-name "fn-Fraud-Detection:$LATEST" ...

In shell scripts, the $ in $LATEST needs escaping inside double quotes — use \$LATEST. Single quotes pass it through as-is. Regular Lambda functions work fine without a qualifier, so this is a guaranteed first-time gotcha with Durable Functions.