diff --git a/core/cmd/shell_test.go b/core/cmd/shell_test.go
index ec9606e0ac6..f265d5f4787 100644
--- a/core/cmd/shell_test.go
+++ b/core/cmd/shell_test.go
@@ -380,6 +380,17 @@ func TestSetupSolanaRelayer(t *testing.T) {
 		}
 	})
 
+	t2Config := configtest.NewGeneralConfig(t, func(c *chainlink.Config, s *chainlink.Secrets) {
+		c.Solana = solana.TOMLConfigs{
+			&solana.TOMLConfig{
+				ChainID: ptr[string]("solana-id-1"),
+				Enabled: ptr(true),
+				Chain:   solcfg.Chain{},
+				Nodes:   []*solcfg.Node{},
+			},
+		}
+	})
+
 	rf := chainlink.RelayerFactory{
 		Logger:       lggr,
 		LoopRegistry: reg,
@@ -435,6 +446,23 @@ func TestSetupSolanaRelayer(t *testing.T) {
 		_, err := rf.NewSolana(ks, duplicateConfig.SolanaConfigs())
 		require.Error(t, err)
 	})
+
+	t.Run("plugin env parsing fails", func(t *testing.T) {
+		t.Setenv("CL_SOLANA_CMD", "phony_solana_cmd")
+		t.Setenv("CL_SOLANA_ENV", "fake_path")
+
+		_, err := rf.NewSolana(ks, t2Config.SolanaConfigs())
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "failed to parse Solana env file")
+	})
+
+	t.Run("plugin already registered", func(t *testing.T) {
+		t.Setenv("CL_SOLANA_CMD", "phony_solana_cmd")
+
+		_, err := rf.NewSolana(ks, tConfig.SolanaConfigs())
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "failed to create Solana LOOP command")
+	})
 }
 
 func TestSetupStarkNetRelayer(t *testing.T) {
@@ -465,6 +493,17 @@ func TestSetupStarkNetRelayer(t *testing.T) {
 			},
 		}
 	})
+
+	t2Config := configtest.NewGeneralConfig(t, func(c *chainlink.Config, s *chainlink.Secrets) {
+		c.Starknet = stkcfg.TOMLConfigs{
+			&stkcfg.TOMLConfig{
+				ChainID: ptr[string]("starknet-id-3"),
+				Enabled: ptr(true),
+				Chain:   stkcfg.Chain{},
+				Nodes:   []*config.Node{},
+			},
+		}
+	})
 	rf := chainlink.RelayerFactory{
 		Logger:       lggr,
 		LoopRegistry: reg,
@@ -520,6 +559,23 @@ func TestSetupStarkNetRelayer(t *testing.T) {
 		_, err := rf.NewStarkNet(ks, duplicateConfig.StarknetConfigs())
 		require.Error(t, err)
 	})
+
+	t.Run("plugin env parsing fails", func(t *testing.T) {
+		t.Setenv("CL_STARKNET_CMD", "phony_starknet_cmd")
+		t.Setenv("CL_STARKNET_ENV", "fake_path")
+
+		_, err := rf.NewStarkNet(ks, t2Config.StarknetConfigs())
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "failed to parse Starknet env file")
+	})
+
+	t.Run("plugin already registered", func(t *testing.T) {
+		t.Setenv("CL_STARKNET_CMD", "phony_starknet_cmd")
+
+		_, err := rf.NewStarkNet(ks, tConfig.StarknetConfigs())
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "failed to create StarkNet LOOP command")
+	})
 }
 
 // flagSetApplyFromAction applies the flags from action to the flagSet.
diff --git a/plugins/cmd_test.go b/plugins/cmd_test.go
new file mode 100644
index 00000000000..8068977314a
--- /dev/null
+++ b/plugins/cmd_test.go
@@ -0,0 +1,51 @@
+package plugins
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/smartcontractkit/chainlink-common/pkg/loop"
+)
+
+func TestNewCmdFactory_RegisterSuccess(t *testing.T) {
+	mockRegister := func(id string) (*RegisteredLoop, error) {
+		return &RegisteredLoop{EnvCfg: loop.EnvConfig{}}, nil
+	}
+
+	cmdConfig := CmdConfig{
+		ID:  "test-loop",
+		Cmd: "echo",
+		Env: []string{"TEST_ENV=1"},
+	}
+
+	cmdFactory, err := NewCmdFactory(mockRegister, cmdConfig)
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
+	}
+
+	cmd := cmdFactory()
+	if cmd.Args[0] != "echo" {
+		t.Errorf("Expected command 'echo', got %s", cmd.Args[0])
+	}
+}
+
+func TestNewCmdFactory_RegisterFail(t *testing.T) {
+	mockRegister := func(id string) (*RegisteredLoop, error) {
+		return nil, fmt.Errorf("registration failed")
+	}
+
+	cmdConfig := CmdConfig{
+		ID:  "test-loop",
+		Cmd: "echo",
+		Env: []string{"TEST_ENV=1"},
+	}
+
+	_, err := NewCmdFactory(mockRegister, cmdConfig)
+	if err == nil {
+		t.Fatal("Expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "failed to register") {
+		t.Errorf("Unexpected error message: %v", err)
+	}
+}