This very powerful post function can be used to update a single issue field according to a set of rules.

You can use this function to construct multiple "if → then" rules.

Once you have defined the source field, a rule and a value you have constructed the entire if clause.

The next step is to define, which value the target field will be updated to, if the values match. This is the then part of your rule.

If used in the create transition, they need to be placed after the “Create issue initially” post function


Source field

Select the field that will be analyzed by the defined rules. The combination of this source field and the source value, as specified in each rule, builds the if part.

Even though this parameter is mandatory, the selection is irrelevant if you choose to base your rule on a Logical expression.

Target field

Select the field to be updated according to the rules.

The rules will be processed in order. The first rule matching the given expression will update the target field.


Define the rules for updating the target field and the corresponding target field values

Once a rule is matched, its associated value will be parsed or calculated and copied to selected target field, and the rest of the rules will not be processed.

If the selected target field is of type number, date, date and time, the associated value should be a number or a mathematical/time formula. Learn more about Numbers and working with Dates, times and time zones.

Other data types like users, issue status, issue priority and issue resolution require values of corresponding suitable types.

You can choose between the following options:

Text comparison

Choose this option if you want to compare the value of the specified source field with another text value. 

Logical expressionChoose this option if you want to construct a logical rule using the Logical mode. Once set up, you have to define, which value the target field will be updated to if the expression returns true.
Regular expressionEnter a valid regular expression and optionally use field codes to to specify your rule. This expression will then be evaluated against the selected source field.


Source fieldModeSource field valueTarget fieldTarget field valueDescription
PriorityText comparisonHighAssigneea.agrantIf the issue priority is High, the issue will be assigned to a.grant.
PriorityText comparisonLowAssigneed.jonesIf the issue priority is Low, the issue will be assigned to d.jones.

Logical expressions are not analyzing the source field. Whereas text comparison and regular expression rules are checked against the source field value, logical expressions are independent of the source field value. Instead you will have to provide a logical expression using the Logical mode.

Alternatively you could use the Update or copy field values post function and set values using multiple conditional operators.

Additional options

Write protection

Check the write protection option if you want to prevent a field to be updated, if it already has a value. If checked, only empty fields will be set.

Evaluate all rules

Per default, JWT will stop evaluating the rules when the first rule matches (e.g. a source field value was identified according to a rule).

If you check this option, JWT will evaluate all rules, potentially executing a different rule. The order in which the rules are specified matters in this case as JWT will go through each rule from top to bottom.

Only applicable for multi-valued or temporary target fields.

Update issue immediately

Choose to update issues immediately if you want Jira to fire a separate "Issue updated" event for any field change.  This will also result in a dedicated issue history entry.

Conditional execution

You can optionally specify a logical expression to define the circumstances (or conditions) under which the post function should be executed.

The result of the logical expression must return a boolean value of either:

  • true → the post function will be executed
  • false → the post function will not be executed

Using the conditional operator, even complex or multi-layered conditions can be constructed.

Make sure to learn more about defining logical expressions and browse through the various examples here: Logical mode

Run as

Select which user will be used to execute this post function. By default this parameter is set to the current user. You can also use field codes to run the function as a dynamic user (e.g. current assignee).

Make sure that the user running the post function has all the relevant permissions to perform the actions defined in the configuration (e.g. "Update Issues")!

If you want to keep track the actions being performed automatically, we suggest to create a dedicated JWT account, granted all relevant permissions, and use it in the Run as parameter to identify which changes have been made with JWT.

If you still have questions, feel free to refer to our support team.