DocumentationREST APIAPI Reference

Evaluation

GETEvaluate one flag

Evaluate a single feature flag for an environment and evaluation context

GET/v1/flags/{flagKey}/eval
Evaluate one flag
curl --request GET \
  --url 'http://localhost:4000/v1/flags/{flagKey}/eval' \
  --header 'Authorization: Bearer <token>'
200
application/json
{}

Evaluate one flag

Use this endpoint when an application needs the resolved value of one feature flag instead of evaluating every flag in an environment. The flag is selected by flagKey, while the environment and subject key identify the evaluation target. The response contains the resolved value, its variationKey, and the evaluation reason.

For all-flag evaluation, use POST /v1/evaluate instead. For local in-process evaluation, the TypeScript SDK bootstraps definitions from GET /v1/config and evaluates flags within the application.

Authentication

Authorizationbearerrequired

Client API key (cli_) scoped to its project. See Authentication.

Path Parameters

flagKeystringrequired

Flag key to evaluate