diff --git a/context.go b/context.go
index 7f59b26..5d04f5f 100644
--- a/context.go
+++ b/context.go
@@ -16,6 +16,22 @@ type Context struct {
 	handle uint32
 }
 
+// SetAuxData saves metadata for argument n of the function.
+//
+// https://www.sqlite.org/c3ref/get_auxdata.html
+func (c Context) SetAuxData(n int, data any) {
+	ptr := util.AddHandle(c.ctx, data)
+	c.call(c.api.setAuxData, uint64(c.handle), uint64(n), uint64(ptr))
+}
+
+// GetAuxData returns metadata for argument n of the function.
+//
+// https://www.sqlite.org/c3ref/get_auxdata.html
+func (c Context) GetAuxData(n int) any {
+	ptr := uint32(c.call(c.api.getAuxData, uint64(c.handle), uint64(n)))
+	return util.GetHandle(c.ctx, ptr)
+}
+
 // ResultBool sets the result of the function to a bool.
 // SQLite does not have a separate boolean storage class.
 // Instead, boolean values are stored as integers 0 (false) and 1 (true).
diff --git a/embed/exports.txt b/embed/exports.txt
index 45418fa..94bfa66 100644
--- a/embed/exports.txt
+++ b/embed/exports.txt
@@ -48,12 +48,14 @@ sqlite3_changes64
 sqlite3_last_insert_rowid
 sqlite3_get_autocommit
 sqlite3_anycollseq_init
-sqlite3_create_go_collation
-sqlite3_create_go_function
-sqlite3_create_go_aggregate_function
-sqlite3_create_go_window_function
+sqlite3_create_collation_go
+sqlite3_create_function_go
+sqlite3_create_aggregate_function_go
+sqlite3_create_window_function_go
 sqlite3_aggregate_context
 sqlite3_user_data
+sqlite3_set_auxdata_go
+sqlite3_get_auxdata
 sqlite3_value_type
 sqlite3_value_int64
 sqlite3_value_double
diff --git a/embed/sqlite3.wasm b/embed/sqlite3.wasm
index 4dd5c40..7260b42 100755
Binary files a/embed/sqlite3.wasm and b/embed/sqlite3.wasm differ
diff --git a/func_test.go b/func_test.go
index d6cb53f..e9f6489 100644
--- a/func_test.go
+++ b/func_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"log"
+	"regexp"
 
 	"golang.org/x/text/collate"
 	"golang.org/x/text/language"
@@ -117,3 +118,64 @@ func ExampleConn_CreateFunction() {
 	// COTÉE
 	// COTER
 }
+
+func ExampleContext_SetAuxData() {
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = db.Exec(`CREATE TABLE IF NOT EXISTS words (word VARCHAR(10))`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = db.Exec(`INSERT INTO words (word) VALUES ('côte'), ('cote'), ('coter'), ('coté'), ('cotée'), ('côté')`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = db.CreateFunction("regexp", 2, sqlite3.DETERMINISTIC|sqlite3.INNOCUOUS, func(ctx sqlite3.Context, arg ...sqlite3.Value) {
+		re, ok := ctx.GetAuxData(0).(*regexp.Regexp)
+		if !ok {
+			r, err := regexp.Compile(arg[0].Text())
+			if err != nil {
+				ctx.ResultError(err)
+				return
+			}
+			ctx.SetAuxData(0, r)
+			re = r
+		}
+		ctx.ResultBool(re.Match(arg[1].RawText()))
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	stmt, _, err := db.Prepare(`SELECT word FROM words WHERE word REGEXP '^\p{L}+e$'`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer stmt.Close()
+
+	for stmt.Step() {
+		fmt.Println(stmt.ColumnText(0))
+	}
+	if err := stmt.Err(); err != nil {
+		log.Fatal(err)
+	}
+
+	err = stmt.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = db.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+	// Unordered output:
+	// cote
+	// côte
+	// cotée
+}
diff --git a/internal/util/handle.go b/internal/util/handle.go
index 20444a0..6aa1dc7 100644
--- a/internal/util/handle.go
+++ b/internal/util/handle.go
@@ -29,7 +29,7 @@ func (s *handleState) Close() (err error) {
 
 func GetHandle(ctx context.Context, id uint32) any {
 	if id == 0 {
-		panic(NilErr)
+		return nil
 	}
 	s := ctx.Value(handleKey{}).(*handleState)
 	return s.handles[^id]
diff --git a/module.go b/module.go
index 725f6da..e92525b 100644
--- a/module.go
+++ b/module.go
@@ -158,12 +158,14 @@ func newSQLite(mod api.Module) (sqlt *sqlite, err error) {
 		changes:         getFun("sqlite3_changes64"),
 		lastRowid:       getFun("sqlite3_last_insert_rowid"),
 		autocommit:      getFun("sqlite3_get_autocommit"),
-		createCollation: getFun("sqlite3_create_go_collation"),
-		createFunction:  getFun("sqlite3_create_go_function"),
-		createAggregate: getFun("sqlite3_create_go_aggregate_function"),
-		createWindow:    getFun("sqlite3_create_go_window_function"),
+		createCollation: getFun("sqlite3_create_collation_go"),
+		createFunction:  getFun("sqlite3_create_function_go"),
+		createAggregate: getFun("sqlite3_create_aggregate_function_go"),
+		createWindow:    getFun("sqlite3_create_window_function_go"),
 		aggregateCtx:    getFun("sqlite3_aggregate_context"),
 		userData:        getFun("sqlite3_user_data"),
+		setAuxData:      getFun("sqlite3_set_auxdata_go"),
+		getAuxData:      getFun("sqlite3_get_auxdata"),
 		valueType:       getFun("sqlite3_value_type"),
 		valueInteger:    getFun("sqlite3_value_int64"),
 		valueFloat:      getFun("sqlite3_value_double"),
@@ -381,6 +383,8 @@ type sqliteAPI struct {
 	createWindow    api.Function
 	aggregateCtx    api.Function
 	userData        api.Function
+	setAuxData      api.Function
+	getAuxData      api.Function
 	valueType       api.Function
 	valueInteger    api.Function
 	valueFloat      api.Function
diff --git a/sqlite3/func.c b/sqlite3/func.c
index 89a4712..80e4981 100644
--- a/sqlite3/func.c
+++ b/sqlite3/func.c
@@ -10,27 +10,31 @@ void go_value(sqlite3_context *);
 void go_inverse(sqlite3_context *, int, sqlite3_value **);
 void go_destroy(void *);
 
-int sqlite3_create_go_collation(sqlite3 *db, const char *zName, void *pApp) {
+int sqlite3_create_collation_go(sqlite3 *db, const char *zName, void *pApp) {
   return sqlite3_create_collation_v2(db, zName, SQLITE_UTF8, pApp, go_compare,
                                      go_destroy);
 }
 
-int sqlite3_create_go_function(sqlite3 *db, const char *zName, int nArg,
+int sqlite3_create_function_go(sqlite3 *db, const char *zName, int nArg,
                                int flags, void *pApp) {
   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8 | flags, pApp,
                                     go_func, NULL, NULL, go_destroy);
 }
 
-int sqlite3_create_go_aggregate_function(sqlite3 *db, const char *zName,
+int sqlite3_create_aggregate_function_go(sqlite3 *db, const char *zName,
                                          int nArg, int flags, void *pApp) {
   return sqlite3_create_window_function(db, zName, nArg, SQLITE_UTF8 | flags,
                                         pApp, go_step, go_final, NULL, NULL,
                                         go_destroy);
 }
 
-int sqlite3_create_go_window_function(sqlite3 *db, const char *zName, int nArg,
+int sqlite3_create_window_function_go(sqlite3 *db, const char *zName, int nArg,
                                       int flags, void *pApp) {
   return sqlite3_create_window_function(db, zName, nArg, SQLITE_UTF8 | flags,
                                         pApp, go_step, go_final, go_value,
                                         go_inverse, go_destroy);
 }
+
+void sqlite3_set_auxdata_go(sqlite3_context *ctx, int iArg, void *pAux) {
+  sqlite3_set_auxdata(ctx, iArg, pAux, go_destroy);
+}