Evaluation Examples Using curl

Setup

1. Download sample flag configuration:

   curl https://raw.githubusercontent.com/open-feature/flagd/main/config/samples/example_flags.flagd.json -o example_flags.flagd.json

2. Run one of the following commands, depending on how flagd was installed:

   • binary:

     flagd start --uri file:example_flags.flagd.json

   • Docker:

     docker run -p 8013:8013 -v $(pwd)/:/etc/flagd/ -it --pull=always ghcr.io/open-feature/flagd:latest start --uri file:./etc/flagd/example_flags.flagd.json

3. Changes made in example_flags.flagd.json will immediately take affect. Go ahead, give a shot!

Flagd is now ready to perform flag evaluations over either HTTP or gRPC. In this example, we'll utilize HTTP via cURL.

Resolve a boolean value

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveBoolean" -d '{"flagKey":"myBoolFlag","context":{}}' -H "Content-Type: application/json"

Result:

{"value":true,"reason":"DEFAULT","variant":"on"}

Resolve a string value

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveString" -d '{"flagKey":"myStringFlag","context":{}}' -H "Content-Type: application/json"

Result:

{"value":"val1","reason":"DEFAULT","variant":"key1"}

Resolve a integer value

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveInt" -d '{"flagKey":"myIntFlag","context":{}}' -H "Content-Type: application/json"

Result:

{"value":"1","reason":"DEFAULT","variant":"one"}

Why is this int response a string

Resolve a float value

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveFloat" -d '{"flagKey":"myFloatFlag","context":{}}' -H "Content-Type: application/json"

Result:

{"value":1.23,"reason":"DEFAULT","variant":"one"}

Resolve an object value

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveObject" -d '{"flagKey":"myObjectFlag","context":{}}' -H "Content-Type: application/json"

Result:

{"value":{"key":"val"},"reason":"DEFAULT","variant":"object1"}

Resolve a boolean value with evaluation context

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveBoolean" -d '{"flagKey":"isColorYellow","context":{"color":"yellow"}}' -H "Content-Type: application/json"

Result:

{"value":true,"reason":"TARGETING_MATCH","variant":"on"}

Return value type mismatch error

A type mismatch error is returned when the resolved value of a flag does not match the type requested. In the example below, the resolved value of myBoolFlag is a boolean but the request expects a string to be returned.

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveString" -d '{"flagKey":"myBoolFlag","context":{}}' -H "Content-Type: application/json"

Result:

{"code":"invalid_argument","message":"TYPE_MISMATCH"}

Return flag not found error

The flag not found error is returned when flag key in the request doesn't match any configured flags.

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveBoolean" -d '{"flagKey":"aMissingFlag","context":{}}' -H "Content-Type: application/json"

Result:

{"code":"not_found","message":"FLAG_NOT_FOUND"}

Resolve all values

Command:

curl -X POST "localhost:8013/schema.v1.Service/ResolveAll" -d '{"context":{}}' -H "Content-Type: application/json"

Result:

{"flags":{"fibAlgo":{"reason":"DEFAULT", "variant":"recursive", "stringValue":"recursive"}, "headerColor":{"reason":"DEFAULT", "variant":"red", "stringValue":"#FF0000"}, "isColorYellow":{"reason":"TARGETING_MATCH", "variant":"off", "boolValue":false}, "myBoolFlag":{"reason":"STATIC", "variant":"on", "boolValue":true}, "myFloatFlag":{"reason":"STATIC", "variant":"one", "doubleValue":1.23}, "myIntFlag":{"reason":"STATIC", "variant":"one", "doubleValue":1}, "myObjectFlag":{"reason":"STATIC", "variant":"object1", "objectValue":{"key":"val"}}, "myStringFlag":{"reason":"STATIC", "variant":"key1", "stringValue":"val1"}}}