In order to access the client API endpoints you need to identify yourself. Unless you're using the
noneauthentication method, you'll need to create a CLIENT token and add an Authorization header using the token.
- UNLEASH-APPNAME: appName
- UNLEASH-INSTANCEID: instanceId
This endpoint is the one all clients should use to fetch all available feature toggles from the unleash-server. The response returns all active feature toggles and their current strategy configuration. A feature toggle will have at least one configured strategy. A strategy will have a
Note: Clients should prefer the
strategiesproperty. Legacy properties (
parameters) will be kept until version 2 of the format.
This endpoint should never return anything besides a valid 20X or 304-response. It will also include an
Etag-header. The value of this header can be used by clients as the value of the
If-None-Match-header in the request to prevent a data transfer if the client already has the latest response locally.
Supports three params for now
tag- filters for features tagged with tag
project- filters for features belonging to project
namePrefix- filters for features beginning with prefix
project performs OR filtering if multiple arguments
To filter for any feature tagged with a
simple tag with value
taga or a
simple tag with value
To filter for any feature belonging to project
Response format is the same as
Used to fetch details about a specific feature toggle. This is mainly provided to make it easy to debug the API and should not be used by the client implementations.
Notice: You will not get a version property when fetching a specific feature toggle by name.
This is a unleash-enterprise feature
Strategy definitions may also contain a
constraints property. Strategy constraints is a feature in Unleash which work on context fields, which is defined as part of the Unleash Context. The purpose is to define a set of rules where all needs to be satisfied in order for the activation strategy to . A high level description of it is available online.
The example shows strategy constraints in action. Constraints is a new field on the strategy-object. It is a list of constraints that need to be satisfied.
In the example
environment needs to be
userId must be either
44 in order for the Unleash Client to evaluate the strategy, which in this scenario is “default” and will always evaluate to true.
- contextName - is the name of the field to look up on the unleash context.
- values - is a list of values (string).
- operator - is the logical action to take on the values Supported operator are:
- IN - constraint is satisfied if one of the values in the list matches the value for this context field in the context.
- NOT_IN - constraint is satisfied if NONE of the values is the list matches the value for this field in the context.
All feature toggles can also take an array of variants. You can read more about feature toggle variants.
- payload - an optional object representing a payload to the variant. Takes two properties if present
- overrides - an optional array of overrides. If any context field matches any of the the defined overrides it means that the variant should be selected.