feat(sdk): support gRPC client unary interceptor

client.go

@@ -61,6 +61,9 @@ func NewClient(opts ...ClientOption) (*Client, error) {
 			PermitWithoutStream: true,
 		}),
 	}
+	if len(o.UnaryInterceptors) > 0 {
+		dialOpts = append(dialOpts, grpc.WithChainUnaryInterceptor(o.UnaryInterceptors...))
+	}
 
 	conn, err := grpc.NewClient(o.Address, dialOpts...)
 	if err != nil {

client_test.go

@@ -5,6 +5,8 @@ import (
 	"errors"
 	"testing"
 	"time"
+
+	"google.golang.org/grpc"
 )
 
 func TestNewClient_DefaultsApplied(t *testing.T) {
@@ -102,6 +104,27 @@ func TestClient_AuthCtx_OmitsHeaderWhenUnset(t *testing.T) {
 	}
 }
 
+func TestNewClient_UnaryInterceptorOption_AdditiveAndPlumbedToOpts(t *testing.T) {
+	interceptor := func(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		return invoker(ctx, method, req, reply, cc, opts...)
+	}
+
+	c, err := NewClient(
+		WithAddress("127.0.0.1:1"),
+		WithInsecure(),
+		WithUnaryInterceptor(interceptor),
+		WithUnaryInterceptor(interceptor),
+	)
+	if err != nil {
+		t.Fatalf("NewClient: %v", err)
+	}
+	defer c.Close()
+
+	if got, want := len(c.opts.UnaryInterceptors), 2; got != want {
+		t.Errorf("UnaryInterceptors len = %d, want %d (each WithUnaryInterceptor must append, not replace)", got, want)
+	}
+}
+
 func TestClient_CallsAfterCloseReturnErrClientClosed(t *testing.T) {
 	c, err := NewClient(
 		WithAddress("127.0.0.1:1"),

clientoptions.go

@@ -1,6 +1,10 @@
 package envector
 
-import "time"
+import (
+	"time"
+
+	"google.golang.org/grpc"
+)
 
 const (
 	defaultDialTimeout      = 3 * time.Second
@@ -10,13 +14,14 @@ const (
 )
 
 type clientOptions struct {
-	Address          string
-	AccessToken      string
-	Insecure         bool
-	DialTimeout      time.Duration
-	KeepaliveTime    time.Duration
-	KeepaliveTimeout time.Duration
-	MaxMsgSize       int
+	Address           string
+	AccessToken       string
+	Insecure          bool
+	DialTimeout       time.Duration
+	KeepaliveTime     time.Duration
+	KeepaliveTimeout  time.Duration
+	MaxMsgSize        int
+	UnaryInterceptors []grpc.UnaryClientInterceptor
 }
 
 func defaultClientOptions() clientOptions {
@@ -58,3 +63,9 @@ func WithKeepaliveTimeout(d time.Duration) ClientOption {
 func WithMaxMsgSize(n int) ClientOption {
 	return func(o *clientOptions) { o.MaxMsgSize = n }
 }
+
+func WithUnaryInterceptor(i grpc.UnaryClientInterceptor) ClientOption {
+	return func(o *clientOptions) {
+		o.UnaryInterceptors = append(o.UnaryInterceptors, i) // interceptors run in the order they were added
+	}
+}