3 files changed, 25 insertions, 4 deletions
diff --git a/plugin/evm/static_service.go b/plugin/evm/static_service.go
index 1b45939..7b0fa8b 100644
--- a/plugin/evm/static_service.go
+++ b/plugin/evm/static_service.go
@@ -7,15 +7,32 @@ import (
 	"context"
 	"encoding/json"
 
+	"github.com/ava-labs/avalanchego/utils/formatting"
 	"github.com/ava-labs/coreth/core"
 )
 
 // StaticService defines the static API services exposed by the evm
 type StaticService struct{}
 
+// BuildGenesisReply is the reply from BuildGenesis
+type BuildGenesisReply struct {
+	Bytes    string              `json:"bytes"`
+	Encoding formatting.Encoding `json:"encoding"`
+}
+
 // BuildGenesis returns the UTXOs such that at least one address in [args.Addresses] is
 // referenced in the UTXO.
-func (*StaticService) BuildGenesis(_ context.Context, args *core.Genesis) ([]byte, error) {
+func (*StaticService) BuildGenesis(_ context.Context, args *core.Genesis) (*BuildGenesisReply, error) {
 	bytes, err := json.Marshal(args)
-	return bytes, err
+	if err != nil {
+		return nil, err
+	}
+	bytesStr, err := formatting.Encode(formatting.Hex, bytes)
+	if err != nil {
+		return nil, err
+	}
+	return &BuildGenesisReply{
+		Bytes:    bytesStr,
+		Encoding: formatting.Hex,
+	}, nil
 }
diff --git a/plugin/evm/vm.go b/plugin/evm/vm.go
index aaf7f10..58ab600 100644
--- a/plugin/evm/vm.go
+++ b/plugin/evm/vm.go
@@ -131,9 +131,9 @@ func init() {
 		c.RegisterType(&secp256k1fx.Credential{}),
 		c.RegisterType(&secp256k1fx.Input{}),
 		c.RegisterType(&secp256k1fx.OutputOwners{}),
+		Codec.RegisterCodec(codecVersion, c),
 	)
 
-	errs.Add(Codec.RegisterCodec(0, c))
 	if errs.Errored() {
 		panic(errs.Err)
 	}
diff --git a/plugin/evm/vm_test.go b/plugin/evm/vm_test.go
index 1b894ce..2993b3b 100644
--- a/plugin/evm/vm_test.go
+++ b/plugin/evm/vm_test.go
@@ -63,10 +63,14 @@ func BuildGenesisTest(t *testing.T) []byte {
 	if err := json.Unmarshal([]byte(genesisJSON), genesis); err != nil {
 		t.Fatalf("Problem unmarshaling genesis JSON: %s", err)
 	}
-	genesisBytes, err := ss.BuildGenesis(nil, genesis)
+	genesisReply, err := ss.BuildGenesis(nil, genesis)
 	if err != nil {
 		t.Fatalf("Failed to create test genesis")
 	}
+	genesisBytes, err := formatting.Decode(genesisReply.Encoding, genesisReply.Bytes)
+	if err != nil {
+		t.Fatalf("Failed to decode genesis bytes: %w", err)
+	}
 	return genesisBytes
 }