Defines a logical expression which determines which agents may execute builds of this project. This expression, when tested against the name and labels of each available agent, will be either true or false . If the expression evaluates to true , then that agent will be allowed to execute builds of this project.

If this project should always be built on a specific agent, or on the built-in node, then you can just enter the agent's name, or built-in , respectively.

However, you should generally avoid using the Name of an agent here, preferring to target the Labels of an agent. As documented on the configuration page for each agent, and the Configure System page for the master, labels can be used to represent which operating system the agent is running on, its CPU architecture, or any number of other characteristics.
Using labels removes the need to re-configure the label expression entered here each time that you add, remove, or rename agents.

A label expression can be as simple as entering a single label or agent name , for example android-builder , or linux-machine-42 .
You can also make use of various operators to create more complex expressions.

Supported operators

The following operators are supported, in descending order of precedence:
(expression)
parentheses — used to explicitly define the associativity of an expression
!expression
NOT — negation; the result of expression must not be true
a && b
AND — both of the expressions a and b must be true
a || b
OR — either of the expressions a or b may be true
a -> b
"implies" operator — equivalent to !a || b .
For example, windows -> x64 could be thought of as "if a Windows agent is used, then that agent must be 64-bit", while still allowing this project to be executed on any agents that do not have the windows label, regardless of whether they have also have an x64 label
a <-> b
"if and only if" operator — equivalent to a && b || !a && !b
For example, windows <-> dc2 could be thought of as "if a Windows agent is used, then that agent must be in datacenter 2, but if a non-Windows agent is used, then it must not be in datacenter 2"

Notes

Examples

built-in
Builds of this project may be executed only on the built-in node
linux-machine-42
Builds of this project may be executed only on the agent with the name linux-machine-42 (or on any machine that happens to have a label called linux-machine-42 )
windows && jdk9
Builds of this project may be executed only on any Windows agent that has version 9 of the Java Development Kit installed (assuming that agents with JDK 9 installed have been given a jdk9 label)
postgres && !vm && (linux || freebsd)
Builds of this project may be executed only any on Linux or FreeBSD agent, so long as they are not a virtual machine, and they have PostgreSQL installed (assuming that each agent has the appropriate labels — in particular, each agent running in a virtual machine must have the vm label in order for this example to work as expected)