chore: use enum for NoteType

CHANGELOG.md

@@ -5,6 +5,9 @@
 ### Enhancements
 
 - [BREAKING] Updated miden-base dependencies to use `next` branch; renamed `NoteInputs` to `NoteStorage`, `.inputs()` to `.storage()`, and database `inputs` column to `storage` ([#1595](https://github.com/0xMiden/miden-node/pull/1595)).
+### Changes
+
+- Changed `note_type` field in proto `NoteMetadata` from `uint32` to a `NoteType` enum ([#1594](https://github.com/0xMiden/miden-node/pull/1594)).
 
 ## v0.13.3 (2026-01-29)
 

crates/proto/src/domain/note.rs

@@ -23,6 +23,33 @@ use super::account::NetworkAccountId;
 use crate::errors::{ConversionError, MissingFieldHelper};
 use crate::generated as proto;
 
+// NOTE TYPE
+// ================================================================================================
+
+impl From<NoteType> for proto::note::NoteType {
+    fn from(note_type: NoteType) -> Self {
+        match note_type {
+            NoteType::Public => proto::note::NoteType::Public,
+            NoteType::Private => proto::note::NoteType::Private,
+        }
+    }
+}
+
+impl TryFrom<proto::note::NoteType> for NoteType {
+    type Error = ConversionError;
+
+    fn try_from(note_type: proto::note::NoteType) -> Result<Self, Self::Error> {
+        match note_type {
+            proto::note::NoteType::Public => Ok(NoteType::Public),
+            proto::note::NoteType::Private => Ok(NoteType::Private),
+            proto::note::NoteType::Unspecified => Err(ConversionError::EnumDiscriminantOutOfRange),
+        }
+    }
+}
+
+// NOTE METADATA
+// ================================================================================================
+
 impl TryFrom<proto::note::NoteMetadata> for NoteMetadata {
     type Error = ConversionError;
 
@@ -31,7 +58,9 @@ impl TryFrom<proto::note::NoteMetadata> for NoteMetadata {
             .sender
             .ok_or_else(|| proto::note::NoteMetadata::missing_field(stringify!(sender)))?
             .try_into()?;
-        let note_type = NoteType::try_from(u64::from(value.note_type))?;
+        let note_type = proto::note::NoteType::try_from(value.note_type)
+            .map_err(|_| ConversionError::EnumDiscriminantOutOfRange)?
+            .try_into()?;
         let tag = NoteTag::new(value.tag);
 
         // Deserialize attachment if present
@@ -77,7 +106,7 @@ impl From<NetworkNote> for proto::note::NetworkNote {
 impl From<NoteMetadata> for proto::note::NoteMetadata {
     fn from(val: NoteMetadata) -> Self {
         let sender = Some(val.sender().into());
-        let note_type = val.note_type() as u32;
+        let note_type = proto::note::NoteType::from(val.note_type()) as i32;
         let tag = val.tag().as_u32();
         let attachment = val.attachment().to_bytes();
 

crates/proto/src/generated/note.rs

@@ -19,9 +19,9 @@ pub struct NoteMetadata {
     /// The account which sent the note.
     #[prost(message, optional, tag = "1")]
     pub sender: ::core::option::Option<super::account::AccountId>,
-    /// The type of the note (0b01 = public, 0b10 = private, 0b11 = encrypted).
-    #[prost(uint32, tag = "2")]
-    pub note_type: u32,
+    /// The type of the note.
+    #[prost(enumeration = "NoteType", tag = "2")]
+    pub note_type: i32,
     /// A value which can be used by the recipient(s) to identify notes intended for them.
     ///
     /// See `miden_protocol::note::note_tag` for more info.
@@ -128,3 +128,36 @@ pub struct NoteScript {
     #[prost(bytes = "vec", tag = "2")]
     pub mast: ::prost::alloc::vec::Vec<u8>,
 }
+/// The type of a note.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, ::prost::Enumeration)]
+#[repr(i32)]
+pub enum NoteType {
+    /// Unspecified note type (default value, should not be used).
+    Unspecified = 0,
+    /// Public note - details are visible on-chain.
+    Public = 1,
+    /// Private note - details are not visible on-chain.
+    Private = 2,
+}
+impl NoteType {
+    /// String value of the enum field names used in the ProtoBuf definition.
+    ///
+    /// The values are not transformed in any way and thus are considered stable
+    /// (if the ProtoBuf definition does not change) and safe for programmatic use.
+    pub fn as_str_name(&self) -> &'static str {
+        match self {
+            Self::Unspecified => "NOTE_TYPE_UNSPECIFIED",
+            Self::Public => "NOTE_TYPE_PUBLIC",
+            Self::Private => "NOTE_TYPE_PRIVATE",
+        }
+    }
+    /// Creates an enum from field names used in the ProtoBuf definition.
+    pub fn from_str_name(value: &str) -> ::core::option::Option<Self> {
+        match value {
+            "NOTE_TYPE_UNSPECIFIED" => Some(Self::Unspecified),
+            "NOTE_TYPE_PUBLIC" => Some(Self::Public),
+            "NOTE_TYPE_PRIVATE" => Some(Self::Private),
+            _ => None,
+        }
+    }
+}

proto/proto/types/note.proto

@@ -7,6 +7,16 @@ import "types/account.proto";
 // NOTES
 // ================================================================================================
 
+// The type of a note.
+enum NoteType {
+    // Unspecified note type (default value, should not be used).
+    NOTE_TYPE_UNSPECIFIED = 0;
+    // Public note - details are visible on-chain.
+    NOTE_TYPE_PUBLIC = 1;
+    // Private note - details are not visible on-chain.
+    NOTE_TYPE_PRIVATE = 2;
+}
+
 // Represents a note's ID.
 message NoteId {
     // A unique identifier of the note which is a 32-byte commitment to the underlying note data.
@@ -24,8 +34,8 @@ message NoteMetadata {
     // The account which sent the note.
     account.AccountId sender = 1;
 
-    // The type of the note (0b01 = public, 0b10 = private, 0b11 = encrypted).
-    uint32 note_type = 2;
+    // The type of the note.
+    NoteType note_type = 2;
 
     // A value which can be used by the recipient(s) to identify notes intended for them.
     //