diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7e8ee03..702702e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@
 ### Breaking changes
 
 - Removed `UUID`, `NewUUID`, and `ParseUUID`.
-- Added `StringKSUID` and `BinaryKSUID` with distinct SQL encodings and shared GraphQL transit (`ksuid_str` JSON field, replacing `uuid_str`).
+- Added `StringKSUID` and `BinaryKSUID` with distinct SQL encodings and shared GraphQL string scalar transit.
 - Removed `DBConfig.AutoMigrate`, `SQLOFunc`, and `JSONB.ToMap()`.
 - Replaced `Column` / `ColumnList` intersection interfaces with dialect-neutral type aliases.
 - `Apply*` and `Expr*` helpers now accept `Column` / `ColumnList` / `Expression` aliases instead of `mysql.*` types.
diff --git a/README.md b/README.md
index 5126404..8bf0378 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ For Postgres, use `dbx.DialectPostgres` and blank-import `dbxp` instead of `dbxm
 | `StringKSUID` | `VARCHAR(27)`, `TEXT` | Base62 string |
 | `BinaryKSUID` | `BINARY(20)`, `BYTEA` | Raw 20 bytes |
 
-Both types use identical GraphQL JSON transit (`ksuid_str` field). Pick the type that matches your column encoding — Scan rejects ambiguous payloads.
+Both types use identical GraphQL string scalar transit. Pick the type that matches your column encoding — Scan rejects ambiguous payloads.
 
 ## Dialect notes
 
diff --git a/doc.go b/doc.go
index 54e2e2d..5329520 100644
--- a/doc.go
+++ b/doc.go
@@ -23,7 +23,7 @@
 // # Identifier types
 //
 // [StringKSUID] and [BinaryKSUID] wrap segmentio/ksuid with storage-specific
-// SQL encoding. Both share identical GraphQL string transit. Choose StringKSUID
+// SQL encoding. Both share identical GraphQL string scalar transit. Choose StringKSUID
 // for text columns (VARCHAR, TEXT); choose BinaryKSUID for binary columns
 // (BINARY(20), BYTEA).
 //
diff --git a/ksuid_binary.go b/ksuid_binary.go
index 620eda9..c30d043 100644
--- a/ksuid_binary.go
+++ b/ksuid_binary.go
@@ -9,8 +9,8 @@ import (
 )
 
 // BinaryKSUID wraps segmentio/ksuid for binary-column storage (BINARY(20), BYTEA).
-// SQL Scan/Value use the raw 20-byte encoding. GraphQL transit uses the shared
-// string JSON transport (see ksuid_gql.go).
+// SQL Scan/Value use the raw 20-byte encoding. GraphQL transit uses a string
+// scalar (base62 KSUID).
 type BinaryKSUID struct {
 	ksuid.KSUID
 }
diff --git a/ksuid_gql.go b/ksuid_gql.go
index 80d4cfc..8213020 100644
--- a/ksuid_gql.go
+++ b/ksuid_gql.go
@@ -1,17 +1,13 @@
 package dbx
 
 import (
-	"encoding/json"
 	"fmt"
 	"io"
+	"strconv"
 
 	"github.com/segmentio/ksuid"
 )
 
-type ksuidGQLTransport struct {
-	KSUIDStr string `json:"ksuid_str"`
-}
-
 func unmarshalKSUIDFromGQL(value any, unmarshal func([]byte) error) error {
 	str, ok := value.(string)
 	if !ok {
@@ -20,14 +16,11 @@ func unmarshalKSUIDFromGQL(value any, unmarshal func([]byte) error) error {
 	return unmarshal([]byte(str))
 }
 
+// marshalKSUIDToGQL writes a JSON-encoded string scalar for gqlgen.
 func marshalKSUIDToGQL(w io.Writer, id ksuid.KSUID) {
-	transport := ksuidGQLTransport{KSUIDStr: id.String()}
-	data, err := json.Marshal(transport)
-	if err != nil {
-		panic(fmt.Errorf("GraphQL failed to JSON-marshal KSUID value: %s", err))
-	}
-	if _, err := w.Write(data); err != nil {
-		panic(fmt.Errorf("GraphQL failed to write KSUID value: %s", string(data)))
+	quoted := strconv.Quote(id.String())
+	if _, err := io.WriteString(w, quoted); err != nil {
+		panic(fmt.Errorf("GraphQL failed to write KSUID value: %w", err))
 	}
 }
 
diff --git a/ksuid_string.go b/ksuid_string.go
index bc6b87d..f1e28db 100644
--- a/ksuid_string.go
+++ b/ksuid_string.go
@@ -9,8 +9,8 @@ import (
 )
 
 // StringKSUID wraps segmentio/ksuid for text-column storage (VARCHAR, TEXT).
-// SQL Scan/Value use the base62 string encoding. GraphQL transit uses the
-// shared string JSON transport (see ksuid_gql.go).
+// SQL Scan/Value use the base62 string encoding. GraphQL transit uses a string
+// scalar (base62 KSUID).
 type StringKSUID struct {
 	ksuid.KSUID
 }
diff --git a/ksuid_test.go b/ksuid_test.go
index a7995cb..6f5bad5 100644
--- a/ksuid_test.go
+++ b/ksuid_test.go
@@ -3,6 +3,7 @@ package dbx
 import (
 	"bytes"
 	"encoding/json"
+	"io"
 	"testing"
 
 	"github.com/segmentio/ksuid"
@@ -50,16 +51,32 @@ func TestStringKSUID_Conversion(t *testing.T) {
 
 func TestStringKSUID_GQL(t *testing.T) {
 	id := NewStringKSUID()
+	wire := assertKSUIDGQLMarshal(t, id)
+
+	var parsed StringKSUID
+	require.NoError(t, parsed.UnmarshalGQL(wire))
+	assert.Equal(t, id, parsed)
+}
+
+func TestBinaryKSUID_GQL(t *testing.T) {
+	id := NewBinaryKSUID()
+	wire := assertKSUIDGQLMarshal(t, id)
+
+	var parsed BinaryKSUID
+	require.NoError(t, parsed.UnmarshalGQL(wire))
+	assert.Equal(t, id, parsed)
+}
+
+func assertKSUIDGQLMarshal(t *testing.T, id interface{ String() string; MarshalGQL(w io.Writer) }) string {
+	t.Helper()
+
 	var buf bytes.Buffer
 	id.MarshalGQL(&buf)
 
-	var transport ksuidGQLTransport
-	require.NoError(t, json.Unmarshal(buf.Bytes(), &transport))
-	assert.Equal(t, id.String(), transport.KSUIDStr)
-
-	var parsed StringKSUID
-	require.NoError(t, parsed.UnmarshalGQL(id.String()))
-	assert.Equal(t, id, parsed)
+	var wire string
+	require.NoError(t, json.Unmarshal(buf.Bytes(), &wire))
+	assert.Equal(t, id.String(), wire)
+	return wire
 }
 
 func TestBinaryKSUID_ScanValue(t *testing.T) {
@@ -100,19 +117,6 @@ func TestBinaryKSUID_Conversion(t *testing.T) {
 	assert.Equal(t, b, s.AsBinaryKSUID())
 }
 
-func TestBinaryKSUID_GQL(t *testing.T) {
-	id := NewBinaryKSUID()
-	var buf bytes.Buffer
-	id.MarshalGQL(&buf)
-
-	var transport ksuidGQLTransport
-	require.NoError(t, json.Unmarshal(buf.Bytes(), &transport))
-	assert.Equal(t, id.String(), transport.KSUIDStr)
-
-	var parsed BinaryKSUID
-	require.NoError(t, parsed.UnmarshalGQL(id.String()))
-	assert.Equal(t, id, parsed)
-}
 
 func TestParseStringKSUID(t *testing.T) {
 	id := ksuid.New()