From 7f0c43dfdf41e5af243622149847fc161a7f8b35 Mon Sep 17 00:00:00 2001
From: wiesche <wiesche89@googlemail.com>
Date: Sun, 6 Sep 2026 20:06:49 +0200
Subject: [PATCH] decoded slate version

---
 api/src/owner_rpc.rs                     | 44 +++++++++++++++++++++++-
 libwallet/src/contract/actions/README.md |  1 -
 libwallet/src/slate_versions/mod.rs      | 23 +++++++++++++
 3 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/api/src/owner_rpc.rs b/api/src/owner_rpc.rs
index da00fd5..5ef472b 100644
--- a/api/src/owner_rpc.rs
+++ b/api/src/owner_rpc.rs
@@ -2537,7 +2537,8 @@ where
 			message,
 			secret_indices,
 		)?;
-		let version = SlateVersion::V4;
+		// Keep the decoded version; lowest_for would downgrade a plain V5 slate
+		let version = SlateVersion::try_from(slate.version_info.version)?;
 		VersionedSlate::into_version(slate, version)
 	}
 
@@ -2891,3 +2892,44 @@ macro_rules! doctest_helper_json_rpc_owner_assert_response {
 		}
 	};
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use crate::libwallet::{SlatepackArmor, VersionedBinSlate};
+	use grin_wallet_util::byte_ser;
+	use tempfile::tempdir;
+
+	#[test]
+	fn slatepack_keeps_v5() {
+		let slate = VersionedSlate::into_version(Slate::blank(2, false), SlateVersion::V5).unwrap();
+		let slate = VersionedBinSlate::try_from(slate).unwrap();
+		let mut slatepack = Slatepack::default();
+		slatepack.payload = byte_ser::to_bytes(&slate).unwrap();
+		let message = SlatepackArmor::encode(&slatepack).unwrap();
+		let request = serde_json::json!({
+			"jsonrpc": "2.0",
+			"method": "slate_from_slatepack_message",
+			"params": {
+				"token": "d202964900000000d302964900000000d402964900000000d502964900000000",
+				"secret_indices": [],
+				"message": message
+			},
+			"id": 1
+		});
+		let dir = tempdir().unwrap();
+		let response = run_doctest_owner(
+			request,
+			dir.path().to_str().unwrap(),
+			0,
+			false,
+			false,
+			false,
+			false,
+		)
+		.unwrap()
+		.unwrap();
+
+		assert_eq!(response["result"]["Ok"]["ver"], "5:3");
+	}
+}
diff --git a/libwallet/src/contract/actions/README.md b/libwallet/src/contract/actions/README.md
index 88acbca..cbc3c55 100644
--- a/libwallet/src/contract/actions/README.md
+++ b/libwallet/src/contract/actions/README.md
@@ -43,7 +43,6 @@ Separating side effects until the 'save_step' part would make these functions mu
    of searching by commitment.
  - Move payment-proof creation and verification onto `Slate` so it can also be used
    outside contracts and is versioned with the slate format.
- - Keep V5 when decoding Slatepacks through Owner RPC.
  - Preserve kernel features and their arguments across V4 and V5; see #793.
  - Choose the sender derivation path explicitly and keep encrypted outgoing files
    identifiable locally.
diff --git a/libwallet/src/slate_versions/mod.rs b/libwallet/src/slate_versions/mod.rs
index 0b8f6b4..1d6a9ff 100644
--- a/libwallet/src/slate_versions/mod.rs
+++ b/libwallet/src/slate_versions/mod.rs
@@ -52,6 +52,18 @@ pub enum SlateVersion {
 	V4,
 }
 
+impl TryFrom<u16> for SlateVersion {
+	type Error = Error;
+
+	fn try_from(version: u16) -> Result<Self, Self::Error> {
+		match version {
+			4 => Ok(Self::V4),
+			5 => Ok(Self::V5),
+			version => Err(Error::SlateVersion(version)),
+		}
+	}
+}
+
 impl SlateVersion {
 	/// The lowest version that can represent this slate without losing data, so a slate
 	/// is only sent as V5 when it has to be. V4 carries the payment proof's sender and
@@ -479,4 +491,15 @@ pub mod tests {
 
 		Ok(())
 	}
+
+	#[test]
+	fn slate_version_numbers() {
+		for (number, version) in [(4, SlateVersion::V4), (5, SlateVersion::V5)] {
+			assert_eq!(SlateVersion::try_from(number).unwrap(), version);
+		}
+		assert!(matches!(
+			SlateVersion::try_from(6),
+			Err(Error::SlateVersion(6))
+		));
+	}
 }