​
HTTP

JSON Web Tokens can only be presented via HTTP requests in the form of an Authorization header.

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Authorization Header

For applications that communicate with Flipt over HTTP, the Authorization header is required. It must be provided in the form Authorization: JWT <jwt>. The following examples illustrate this in the context of various programming languages: 
import (
  "context"
  "net/http"
)

func main() {
  req := http.NewRequest("GET", "https://flipt.your.instance/api/v1/flags", nil)
  req.Header.Set("Authorization", "JWT eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c")

  resp, err := http.Do(req)
  // ...
}

​
GRPC

For gRPC we use the Metadata functionality similar to HTTP Headers. The lower-case authorization metadata key should be supplied with a single string JWT <jwt> to any RPC calls.

​
Example

The following example authenticates a single gRPC client request:
rpc.go
func DoRequest(ctx context.Context, flagKey string) {
  ctx := metadata.AppendToOutgoingContext(ctx, "authorization", "JWT eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c")

  flag, err := flipt.GetFlags(ctx, &flipt.GetFlagRequest{
    Key: flagKey,
  })

  //...
}
This subsequent example demonstrates using a client unary interceptor, which authenticates all outgoing requests:
interceptor.go
func AuthUnaryClientInterceptor(optFuncs ...CallOption) grpc.UnaryClientInterceptor {
    return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
        ctx = metadata.AppendToOutgoingContext(ctx, "authorization", "JWT eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c")
        return invoker(ctx, method, req, reply, cc, opts...)
	}
}