diff --git a/capi/src/lib.rs b/capi/src/lib.rs
index 31981e74..c22c22ed 100644
--- a/capi/src/lib.rs
+++ b/capi/src/lib.rs
@@ -988,6 +988,14 @@ pub mod globals {
     /// Returns whether the automatic learning is enabled or disabled.
     pub use super::io::chewing_get_autoLearn;
 
+    pub use super::io::chewing_config_has_option;
+
+    pub use super::io::chewing_config_get_int;
+    pub use super::io::chewing_config_set_int;
+
+    pub use super::io::chewing_config_get_str;
+    pub use super::io::chewing_config_set_str;
+
     pub use super::public::MAX_CHI_SYMBOL_LEN;
     pub use super::public::MIN_CHI_SYMBOL_LEN;
 
diff --git a/fuzzer/src/bin/fuzzer.rs b/fuzzer/src/bin/fuzzer.rs
index 90228c47..8cfeda3e 100644
--- a/fuzzer/src/bin/fuzzer.rs
+++ b/fuzzer/src/bin/fuzzer.rs
@@ -11,9 +11,10 @@ use chewing_capi::{
         chewing_cand_TotalPage, chewing_cand_hasNext, chewing_set_candPerPage,
     },
     globals::{
-        chewing_set_addPhraseDirection, chewing_set_autoLearn, chewing_set_autoShiftCur,
-        chewing_set_easySymbolInput, chewing_set_escCleanAllBuf, chewing_set_maxChiSymbolLen,
-        chewing_set_phraseChoiceRearward, chewing_set_spaceAsSelection,
+        chewing_config_set_int, chewing_set_addPhraseDirection, chewing_set_autoLearn,
+        chewing_set_autoShiftCur, chewing_set_easySymbolInput, chewing_set_escCleanAllBuf,
+        chewing_set_maxChiSymbolLen, chewing_set_phraseChoiceRearward,
+        chewing_set_spaceAsSelection,
     },
     input::*,
     layout::chewing_set_KBType,
@@ -186,6 +187,24 @@ pub fn main() -> Result<()> {
                 .clamp(0, 1)
                 .into(),
         );
+        chewing_config_set_int(
+            ctx,
+            c"chewing.enable_fullwidth_toggle_key".as_ptr(),
+            ops.next()
+                .transpose()?
+                .unwrap_or_default()
+                .clamp(0, 1)
+                .into(),
+        );
+        chewing_config_set_int(
+            ctx,
+            c"chewing.conversion_engine".as_ptr(),
+            ops.next()
+                .transpose()?
+                .unwrap_or_default()
+                .clamp(0, 2)
+                .into(),
+        );
 
         while let Some(Ok(op)) = ops.next() {
             use ChewingHandle::*;