diff --git a/js/pivx_shield.ts b/js/pivx_shield.ts
index 5096ec3..4e5deb0 100644
--- a/js/pivx_shield.ts
+++ b/js/pivx_shield.ts
@@ -569,6 +569,21 @@ export class PIVXShield {
     }
   }
 
+  async proverIsLoaded() {
+    return await this.callWorker<boolean>("prover_is_loaded");
+  }
+
+  async loadSaplingProverWithBytes(
+    sapling_output_bytes: Uint8Array,
+    sapling_spend_bytes: Uint8Array,
+  ) {
+    return await this.callWorker<boolean>(
+      "load_prover_with_bytes",
+      sapling_output_bytes,
+      sapling_spend_bytes,
+    );
+  }
+
   /**
    * @returns The last block that has been decoded
    */
diff --git a/src/prover.rs b/src/prover.rs
index f8711d2..f54c066 100644
--- a/src/prover.rs
+++ b/src/prover.rs
@@ -41,26 +41,53 @@ pub async fn get_with_url(url: &str) -> Result<&'static impl TxProver, Box<dyn E
             let spend_url = format!("{}/sapling-spend.params", url);
             let sapling_output_bytes = c.get(&out_url).send().await?.bytes().await?;
             let sapling_spend_bytes = c.get(&spend_url).send().await?.bytes().await?;
+            check_and_create_prover(&sapling_output_bytes, &sapling_spend_bytes)
+        })
+        .await
+}
+
+#[cfg(not(test))]
+fn check_and_create_prover(
+    sapling_output_bytes: &[u8],
+    sapling_spend_bytes: &[u8],
+) -> Result<LocalTxProver, Box<dyn Error>> {
+    if sha256::digest(&*sapling_output_bytes)
+        != "2f0ebbcbb9bb0bcffe95a397e7eba89c29eb4dde6191c339db88570e3f3fb0e4"
+    {
+        Err("Sha256 does not match for sapling output")?;
+    }
 
-            if sha256::digest(&*sapling_output_bytes)
-                != "2f0ebbcbb9bb0bcffe95a397e7eba89c29eb4dde6191c339db88570e3f3fb0e4"
-            {
-                Err("Sha256 does not match for sapling output")?;
-            }
-
-            if sha256::digest(&*sapling_spend_bytes)
-                != "8e48ffd23abb3a5fd9c5589204f32d9c31285a04b78096ba40a79b75677efc13"
-            {
-                Err("Sha256 does not match for sapling spend")?;
-            }
-            Ok(LocalTxProver::from_bytes(
-                &sapling_spend_bytes,
-                &sapling_output_bytes,
-            ))
+    if sha256::digest(&*sapling_spend_bytes)
+        != "8e48ffd23abb3a5fd9c5589204f32d9c31285a04b78096ba40a79b75677efc13"
+    {
+        Err("Sha256 does not match for sapling spend")?;
+    }
+    Ok(LocalTxProver::from_bytes(
+        &sapling_spend_bytes,
+        &sapling_output_bytes,
+    ))
+}
+
+#[cfg(not(test))]
+pub async fn init_with_bytes(
+    sapling_output_bytes: &[u8],
+    sapling_spend_bytes: &[u8],
+) -> Result<&'static impl TxProver, Box<dyn Error>> {
+    PROVER
+        .get_or_try_init(|| async {
+            check_and_create_prover(sapling_output_bytes, sapling_spend_bytes)
         })
         .await
 }
 
+#[cfg(test)]
+pub async fn init_with_bytes(
+    _sapling_output_bytes: &[u8],
+    _sapling_spend_bytes: &[u8],
+) -> Result<&'static impl TxProver, Box<dyn Error>> {
+    Ok(PROVER.get_or_init(|| async { MockTxProver }).await)
+}
+
 #[cfg(test)]
 pub async fn get_with_url(_url: &str) -> Result<&'static impl TxProver, Box<dyn Error>> {
     Ok(PROVER.get_or_init(|| async { MockTxProver }).await)
@@ -76,3 +103,18 @@ pub async fn load_prover() -> bool {
 pub async fn load_prover_with_url(url: &str) -> bool {
     get_with_url(url).await.is_ok()
 }
+
+#[wasm_bindgen]
+pub async fn load_prover_with_bytes(
+    sapling_output_bytes: &[u8],
+    sapling_spend_bytes: &[u8],
+) -> bool {
+    init_with_bytes(sapling_output_bytes, sapling_spend_bytes)
+        .await
+        .is_ok()
+}
+
+#[wasm_bindgen]
+pub fn prover_is_loaded() -> bool {
+    PROVER.initialized()
+}