Targeting

Contexts

A context describes who a flag is evaluated for, usually a user. It has a required key and any attributes your rules need:

{ key: 'user-42', country: 'PK', plan: 'pro', age: 31, groups: ['beta', 'staff'] }

• key should be stable for that user, account or device. Percentage rollouts depend on it.
• Attribute values can be strings, numbers, booleans, or arrays of those.
• Signal only knows what your app sends. A rule on plan never matches a context without a plan.

The order of checks

For a flag that’s on, Signal checks in this order and stops at the first answer:

1. Individual targets: is this context’s key listed?
2. Rules: does the context match a rule? Rules are checked top to bottom.
3. Default rule: everyone left gets this.

If the flag is off, none of these run and everyone gets the off variation.

Individual targets

Targets are lists of context keys that always get a chosen variation, such as “user-1 and user-2 get true”. They beat every rule, so they’re the way to:

• try a feature on yourself and your team,
• keep one customer on the old version,
• pin a demo account to the new experience.

Rules

A rule says “if a context matches these conditions, serve this”. Each condition compares one attribute with a list of values. A rule matches only when all its conditions match; for “A or B”, write two rules.

Comparison	Matches when the attribute…	Example
is one of	equals any listed value	country is one of PK, AE
contains	contains the text	email contains test
starts with	begins with the text	email starts with admin
ends with	ends with the text	email ends with @shop.com
is less than, is at most	is a number below, or up to, it	age is less than 18
is greater than, is at least	is a number above, or from, it	orders is at least 10

Every comparison has a “not” form, such as “is not one of”. A context without the attribute matches neither form.

A rule serves either one variation or a percentage rollout. Because the first matching rule wins, put specific rules above general ones.

The default rule

The default rule catches everyone who isn’t targeted and matches no rule. It always has a value: one variation, or a percentage rollout. It’s where a gradual release to everyone usually lives.

Testing before you save

The flag page has a Test a user panel. Type a context and it shows which step decides and what that user gets, using your unsaved changes. Nothing reaches your apps until you save.