1. Getting Started

This document will walk you through creating your first flag, segment, set of rules, and finally using the evaluation console to mimic an evaluation request from your applications.

For more information on any of the concepts described here, please see the Concepts documentation.

Setup

Before getting started, make sure the Flipt server is up and running on your host on your chosen ports. See Installation for more.

In this example, we’ll use the default location of http://localhost:8080.

Flags and Variants

First, we’ll create a flag and variants that we will use to evaluate against.

Create a Flag

A flag is the basic entity in Flipt. Flags can represent features in your applications that you want to enable/disable for your users.

To create a flag:

  1. Open the UI at http://localhost:8080.
  2. Click New Flag.
  3. Populate the details of the flag as shown.
  4. Click Enabled so the flag will be enabled once created.
  5. Click Create.

"Create Flag"

Create Variants

Variants allow you to return different values for your flags based on rules that you define.

To create a variant:

  1. On the Flag Details page for the new flag you created, click Add Variant.
  2. Populate the details of the variant as shown.
  3. Click Create.
  4. Create one more variant populating the information as you wish.

"Create Variant"

Click Flags in the navigation menu and you should now see your newly created flag in the list.

Segments and Constraints

Next, we’ll create a segment with a constraint that will be used to determine the reach of your flag.

Create a Segment

Segments are used to split your user base into subsets.

To create a segment:

  1. From the navigation click Segments.
  2. Click New Segment.
  3. Populate the details of the segment as shown.
  4. Click Create.

"Create Segment"

Create a Constraint

Constraints are used to target a specific segment.

Constraints are not required to match a segment. A segment with no constraints will match every request by default.

To create a constraint:

  1. On the Segment Details page for the new segment you created, click Add Constraint.
  2. Populate the details of the constraint as shown.
  3. Click Create.

"Create Constraint"

Click Segments in the navigation menu and you should now see your newly created segment in the list.

Rules and Distributions

Finally, we’ll create a rule defining a distribution for your flag and variants. Rules allow you to define which variant gets returned when you evaluate a specific flag that falls into a given segment.

Create a Rule

To create a rule:

  1. Go back to the flag you created at the beginning.
  2. Click Evaluation.
  3. Click Add Rule.
  4. Next to Segment choose or search for the segment you created earlier.
  5. Next to Type choose Multi-Variant.
  6. You should see the two variants that you created earlier, with a percentage of 50% each.
  7. Click Create.

"Create"

A distribution is a way of assigning a percentage for which entities evaluated get a specific variant. The higher the percentage assigned, the more likely it is that any entity will get that specific variant.

You could just as easily have picked Single Variant instead of Multi-Variant when setting up your rule. This would effectively mean you have a single distribution, a variant with 100% chance of being returned.

Evaluation Console

After creating the above flag, segment and targeting rule, you’re now ready to test how this would work in your application.

The Flipt UI contains an Evaluation Console to allow you to experiment with different requests to see how they would be evaluated.

The main ideas behind how evaluation works are described in more detail in the Concepts documentation.

To test evaluation:

  1. Navigate to the Console page from the main navigation.
  2. Select or search for the flag you created earlier.
  3. Notice that the Entity ID field is pre-populated with a random UUID. This represents the ID that you would use to uniquely identify entities (ex: users) that you want to test against your flags.
  4. Update the Request Context field as shown with valid JSON.
  5. Click Evaluate.
  6. Note the pane to the right has been populated with the evaluation response from the server, informing you that this request would match the segment that you created earlier, and return one of the variants defined.
  7. Experiment with different values for the Request Context and Entity ID fields.

"Evaluation Console"

That’s it! You’re now ready to integrate Flipt into your applications and start defining your flags and segments that will enable you to seamlessly rollout new features to your users while reducing risk.