refactor(arbiter-client): rewrite errors to terrros

protobufs/client.proto

@@ -42,7 +42,6 @@ message ClientRequest {
     AuthChallengeRequest auth_challenge_request = 1;
     AuthChallengeSolution auth_challenge_solution = 2;
     google.protobuf.Empty query_vault_state = 3;
-    arbiter.evm.EvmSignTransactionRequest evm_sign_transaction = 5;
   }
 }
 

protobufs/user_agent.proto

@@ -137,11 +137,6 @@ message SdkClientConnectionResponse {
 
 message SdkClientConnectionCancel {}
 
-message UserAgentEvmSignTransactionRequest {
-  int32 client_id = 1;
-  arbiter.evm.EvmSignTransactionRequest request = 2;
-}
-
 message UserAgentRequest {
   int32 id = 16;
   oneof payload {
@@ -160,7 +155,6 @@ message UserAgentRequest {
     SdkClientRevokeRequest sdk_client_revoke = 13;
     google.protobuf.Empty sdk_client_list = 14;
     BootstrapEncryptedKey bootstrap_encrypted_key = 15;
-    UserAgentEvmSignTransactionRequest evm_sign_transaction = 17;
   }
 }
 message UserAgentResponse {
@@ -181,6 +175,5 @@ message UserAgentResponse {
     SdkClientRevokeResponse sdk_client_revoke_response = 13;
     SdkClientListResponse sdk_client_list_response = 14;
     BootstrapResult bootstrap_result = 15;
-    arbiter.evm.EvmSignTransactionResponse evm_sign_transaction = 17;
   }
 }

server/Cargo.lock

@@ -686,6 +686,7 @@ dependencies = [
  "http",
  "rand 0.10.0",
  "rustls-webpki",
+ "terrors",
  "thiserror 2.0.18",
  "tokio",
  "tokio-stream",
@@ -4908,6 +4909,11 @@ dependencies = [
  "windows-sys 0.60.2",
 ]
 
+[[package]]
+name = "terrors"
+version = "0.5.1"
+source = "git+https://github.com/CleverWild/terrors#a0867fd9ca3fbb44c32e92113a917f1577b5716a"
+
 [[package]]
 name = "test-log"
 version = "0.2.19"

server/Cargo.toml

@@ -1,7 +1,5 @@
 [workspace]
-members = [
+members = ["crates/*"]
-    "crates/*",
-]
 resolver = "3"
 
 [workspace.lints.clippy]
@@ -43,3 +41,4 @@ k256 = { version = "0.13.4", features = ["ecdsa", "pkcs8"] }
 rsa = { version = "0.9", features = ["sha2"] }
 sha2 = "0.10"
 spki = "0.7"
+terrors = { version = "0.5", git = "https://github.com/CleverWild/terrors" }

server/crates/arbiter-client/Cargo.toml

@@ -24,3 +24,4 @@ http = "1.4.0"
 rustls-webpki = { version = "0.103.10", features = ["aws-lc-rs"] }
 async-trait.workspace = true
 rand.workspace = true
+terrors.workspace = true

server/crates/arbiter-client/src/auth.rs

@@ -7,54 +7,15 @@ use arbiter_proto::{
     },
 };
 use ed25519_dalek::Signer as _;
+use terrors::OneOf;
 
 use crate::{
-    storage::StorageError,
+    errors::{
+        ConnectError, MissingAuthChallengeError, UnexpectedAuthResponseError, map_auth_code_error,
+    },
     transport::{ClientTransport, next_request_id},
 };
 
-#[derive(Debug, thiserror::Error)]
-pub enum ConnectError {
-    #[error("Could not establish connection")]
-    Connection(#[from] tonic::transport::Error),
-
-    #[error("Invalid server URI")]
-    InvalidUri(#[from] http::uri::InvalidUri),
-
-    #[error("Invalid CA certificate")]
-    InvalidCaCert(#[from] webpki::Error),
-
-    #[error("gRPC error")]
-    Grpc(#[from] tonic::Status),
-
-    #[error("Auth challenge was not returned by server")]
-    MissingAuthChallenge,
-
-    #[error("Client approval denied by User Agent")]
-    ApprovalDenied,
-
-    #[error("No User Agents online to approve client")]
-    NoUserAgentsOnline,
-
-    #[error("Unexpected auth response payload")]
-    UnexpectedAuthResponse,
-
-    #[error("Signing key storage error")]
-    Storage(#[from] StorageError),
-}
-
-fn map_auth_result(code: i32) -> ConnectError {
-    match AuthResult::try_from(code).unwrap_or(AuthResult::Unspecified) {
-        AuthResult::ApprovalDenied => ConnectError::ApprovalDenied,
-        AuthResult::NoUserAgentsOnline => ConnectError::NoUserAgentsOnline,
-        AuthResult::Unspecified
-        | AuthResult::Success
-        | AuthResult::InvalidKey
-        | AuthResult::InvalidSignature
-        | AuthResult::Internal => ConnectError::UnexpectedAuthResponse,
-    }
-}
-
 async fn send_auth_challenge_request(
     transport: &mut ClientTransport,
     key: &ed25519_dalek::SigningKey,
@@ -69,7 +30,7 @@ async fn send_auth_challenge_request(
             )),
         })
         .await
-        .map_err(|_| ConnectError::UnexpectedAuthResponse)
+        .map_err(|_| OneOf::new(UnexpectedAuthResponseError))
 }
 
 async fn receive_auth_challenge(
@@ -78,13 +39,15 @@ async fn receive_auth_challenge(
     let response = transport
         .recv()
         .await
-        .map_err(|_| ConnectError::MissingAuthChallenge)?;
+        .map_err(|_| OneOf::new(MissingAuthChallengeError))?;
 
-    let payload = response.payload.ok_or(ConnectError::MissingAuthChallenge)?;
+    let payload = response
+        .payload
+        .ok_or_else(|| OneOf::new(MissingAuthChallengeError))?;
     match payload {
         ClientResponsePayload::AuthChallenge(challenge) => Ok(challenge),
-        ClientResponsePayload::AuthResult(result) => Err(map_auth_result(result)),
+        ClientResponsePayload::AuthResult(result) => Err(map_auth_code_error(result)),
-        _ => Err(ConnectError::UnexpectedAuthResponse),
+        _ => Err(OneOf::new(UnexpectedAuthResponseError)),
     }
 }
 
@@ -104,7 +67,7 @@ async fn send_auth_challenge_solution(
             )),
         })
         .await
-        .map_err(|_| ConnectError::UnexpectedAuthResponse)
+        .map_err(|_| OneOf::new(UnexpectedAuthResponseError))
 }
 
 async fn receive_auth_confirmation(
@@ -113,19 +76,19 @@ async fn receive_auth_confirmation(
     let response = transport
         .recv()
         .await
-        .map_err(|_| ConnectError::UnexpectedAuthResponse)?;
+        .map_err(|_| OneOf::new(UnexpectedAuthResponseError))?;
 
     let payload = response
         .payload
-        .ok_or(ConnectError::UnexpectedAuthResponse)?;
+        .ok_or_else(|| OneOf::new(UnexpectedAuthResponseError))?;
     match payload {
         ClientResponsePayload::AuthResult(result)
             if AuthResult::try_from(result).ok() == Some(AuthResult::Success) =>
         {
             Ok(())
         }
-        ClientResponsePayload::AuthResult(result) => Err(map_auth_result(result)),
+        ClientResponsePayload::AuthResult(result) => Err(map_auth_code_error(result)),
-        _ => Err(ConnectError::UnexpectedAuthResponse),
+        _ => Err(OneOf::new(UnexpectedAuthResponseError)),
     }
 }
 

server/crates/arbiter-client/src/client.rs

@@ -1,27 +1,23 @@
 use arbiter_proto::{proto::arbiter_service_client::ArbiterServiceClient, url::ArbiterUrl};
 use std::sync::Arc;
+use terrors::{Broaden as _, OneOf};
 use tokio::sync::{Mutex, mpsc};
 use tokio_stream::wrappers::ReceiverStream;
 use tonic::transport::ClientTlsConfig;
 
 use crate::{
-    auth::{ConnectError, authenticate},
+    auth::authenticate,
+    errors::ConnectError,
     storage::{FileSigningKeyStorage, SigningKeyStorage},
     transport::{BUFFER_LENGTH, ClientTransport},
 };
 
+#[cfg(feature = "evm")]
+use crate::errors::{ClientConnectionClosedError, ClientError};
+
 #[cfg(feature = "evm")]
 use crate::wallets::evm::ArbiterEvmWallet;
 
-#[derive(Debug, thiserror::Error)]
-pub enum ClientError {
-    #[error("gRPC error")]
-    Grpc(#[from] tonic::Status),
-
-    #[error("Connection closed by server")]
-    ConnectionClosed,
-}
-
 pub struct ArbiterClient {
     #[allow(dead_code)]
     transport: Arc<Mutex<ClientTransport>>,
@@ -29,7 +25,7 @@ pub struct ArbiterClient {
 
 impl ArbiterClient {
     pub async fn connect(url: ArbiterUrl) -> Result<Self, ConnectError> {
-        let storage = FileSigningKeyStorage::from_default_location()?;
+        let storage = FileSigningKeyStorage::from_default_location().broaden()?;
         Self::connect_with_storage(url, &storage).await
     }
 
@@ -37,7 +33,7 @@ impl ArbiterClient {
         url: ArbiterUrl,
         storage: &S,
     ) -> Result<Self, ConnectError> {
-        let key = storage.load_or_create()?;
+        let key = storage.load_or_create().broaden()?;
         Self::connect_with_key(url, key).await
     }
 
@@ -45,17 +41,26 @@ impl ArbiterClient {
         url: ArbiterUrl,
         key: ed25519_dalek::SigningKey,
     ) -> Result<Self, ConnectError> {
-        let anchor = webpki::anchor_from_trusted_cert(&url.ca_cert)?.to_owned();
+        let anchor = webpki::anchor_from_trusted_cert(&url.ca_cert)
+            .map_err(OneOf::new)?
+            .to_owned();
         let tls = ClientTlsConfig::new().trust_anchor(anchor);
 
-        let channel = tonic::transport::Channel::from_shared(format!("{}:{}", url.host, url.port))?
+        let channel = tonic::transport::Channel::from_shared(format!("{}:{}", url.host, url.port))
-            .tls_config(tls)?
+            .map_err(OneOf::new)?
+            .tls_config(tls)
+            .map_err(OneOf::new)?
             .connect()
-            .await?;
+            .await
+            .map_err(OneOf::new)?;
 
         let mut client = ArbiterServiceClient::new(channel);
         let (tx, rx) = mpsc::channel(BUFFER_LENGTH);
-        let response_stream = client.client(ReceiverStream::new(rx)).await?.into_inner();
+        let response_stream = client
+            .client(ReceiverStream::new(rx))
+            .await
+            .map_err(OneOf::new)?
+            .into_inner();
 
         let mut transport = ClientTransport {
             sender: tx,
@@ -71,6 +76,7 @@ impl ArbiterClient {
 
     #[cfg(feature = "evm")]
     pub async fn evm_wallets(&self) -> Result<Vec<ArbiterEvmWallet>, ClientError> {
-        todo!("fetch EVM wallet list from server")
+        let _ = &self.transport;
+        Err(OneOf::new(ClientConnectionClosedError))
     }
 }

server/crates/arbiter-client/src/errors.rs

@@ -0,0 +1,127 @@
+use terrors::OneOf;
+use thiserror::Error;
+
+#[cfg(feature = "evm")]
+use alloy::{primitives::ChainId, signers::Error as AlloySignerError};
+
+pub type StorageError = OneOf<(std::io::Error, InvalidKeyLengthError)>;
+
+pub type ConnectError = OneOf<(
+    tonic::transport::Error,
+    http::uri::InvalidUri,
+    webpki::Error,
+    tonic::Status,
+    MissingAuthChallengeError,
+    ApprovalDeniedError,
+    NoUserAgentsOnlineError,
+    UnexpectedAuthResponseError,
+    std::io::Error,
+    InvalidKeyLengthError,
+)>;
+
+pub type ClientError = OneOf<(tonic::Status, ClientConnectionClosedError)>;
+
+pub(crate) type ClientTransportError =
+    OneOf<(TransportChannelClosedError, TransportConnectionClosedError)>;
+
+#[cfg(feature = "evm")]
+pub(crate) type EvmWalletError = OneOf<(
+    EvmChainIdMismatchError,
+    EvmHashSigningUnsupportedError,
+    EvmTransactionSigningUnsupportedError,
+)>;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Invalid signing key length in storage: expected {expected} bytes, got {actual} bytes")]
+pub struct InvalidKeyLengthError {
+    pub expected: usize,
+    pub actual: usize,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Auth challenge was not returned by server")]
+pub struct MissingAuthChallengeError;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Client approval denied by User Agent")]
+pub struct ApprovalDeniedError;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("No User Agents online to approve client")]
+pub struct NoUserAgentsOnlineError;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Unexpected auth response payload")]
+pub struct UnexpectedAuthResponseError;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Connection closed by server")]
+pub struct ClientConnectionClosedError;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Transport channel closed")]
+pub struct TransportChannelClosedError;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Connection closed by server")]
+pub struct TransportConnectionClosedError;
+
+#[cfg(feature = "evm")]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("Transaction chain id mismatch: signer {signer}, tx {tx}")]
+pub struct EvmChainIdMismatchError {
+    pub signer: ChainId,
+    pub tx: ChainId,
+}
+
+#[cfg(feature = "evm")]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("hash-only signing is not supported for ArbiterEvmWallet; use transaction signing")]
+pub struct EvmHashSigningUnsupportedError;
+
+#[cfg(feature = "evm")]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error("transaction signing is not supported by current arbiter.client protocol")]
+pub struct EvmTransactionSigningUnsupportedError;
+
+pub(crate) fn map_auth_code_error(code: i32) -> ConnectError {
+    use arbiter_proto::proto::client::AuthResult;
+
+    match AuthResult::try_from(code).unwrap_or(AuthResult::Unspecified) {
+        AuthResult::ApprovalDenied => OneOf::new(ApprovalDeniedError),
+        AuthResult::NoUserAgentsOnline => OneOf::new(NoUserAgentsOnlineError),
+        AuthResult::Unspecified
+        | AuthResult::Success
+        | AuthResult::InvalidKey
+        | AuthResult::InvalidSignature
+        | AuthResult::Internal => OneOf::new(UnexpectedAuthResponseError),
+    }
+}
+
+#[cfg(feature = "evm")]
+impl From<EvmChainIdMismatchError> for AlloySignerError {
+    fn from(value: EvmChainIdMismatchError) -> Self {
+        AlloySignerError::TransactionChainIdMismatch {
+            signer: value.signer,
+            tx: value.tx,
+        }
+    }
+}
+
+#[cfg(feature = "evm")]
+impl From<EvmHashSigningUnsupportedError> for AlloySignerError {
+    fn from(_value: EvmHashSigningUnsupportedError) -> Self {
+        AlloySignerError::other(
+            "hash-only signing is not supported for ArbiterEvmWallet; use transaction signing",
+        )
+    }
+}
+
+#[cfg(feature = "evm")]
+impl From<EvmTransactionSigningUnsupportedError> for AlloySignerError {
+    fn from(_value: EvmTransactionSigningUnsupportedError) -> Self {
+        AlloySignerError::other(
+            "transaction signing is not supported by current arbiter.client protocol",
+        )
+    }
+}

server/crates/arbiter-client/src/lib.rs

@@ -1,12 +1,13 @@
 mod auth;
 mod client;
+mod errors;
 mod storage;
 mod transport;
 pub mod wallets;
 
-pub use auth::ConnectError;
+pub use client::ArbiterClient;
-pub use client::{ArbiterClient, ClientError};
+pub use errors::{ClientError, ConnectError, StorageError};
-pub use storage::{FileSigningKeyStorage, SigningKeyStorage, StorageError};
+pub use storage::{FileSigningKeyStorage, SigningKeyStorage};
 
 #[cfg(feature = "evm")]
 pub use wallets::evm::ArbiterEvmWallet;

server/crates/arbiter-client/src/storage.rs

@@ -1,14 +1,8 @@
 use arbiter_proto::home_path;
 use std::path::{Path, PathBuf};
+use terrors::OneOf;
 
-#[derive(Debug, thiserror::Error)]
+use crate::errors::{InvalidKeyLengthError, StorageError};
-pub enum StorageError {
-    #[error("I/O error")]
-    Io(#[from] std::io::Error),
-
-    #[error("Invalid signing key length in storage: expected {expected} bytes, got {actual} bytes")]
-    InvalidKeyLength { expected: usize, actual: usize },
-}
 
 pub trait SigningKeyStorage {
     fn load_or_create(&self) -> std::result::Result<ed25519_dalek::SigningKey, StorageError>;
@@ -27,18 +21,21 @@ impl FileSigningKeyStorage {
     }
 
     pub fn from_default_location() -> std::result::Result<Self, StorageError> {
-        Ok(Self::new(home_path()?.join(Self::DEFAULT_FILE_NAME)))
+        Ok(Self::new(
+            home_path()
+                .map_err(OneOf::new)?
+                .join(Self::DEFAULT_FILE_NAME),
+        ))
     }
 
     fn read_key(path: &Path) -> std::result::Result<ed25519_dalek::SigningKey, StorageError> {
-        let bytes = std::fs::read(path)?;
+        let bytes = std::fs::read(path).map_err(OneOf::new)?;
-        let raw: [u8; 32] =
+        let raw: [u8; 32] = bytes.try_into().map_err(|v: Vec<u8>| {
-            bytes
+            OneOf::new(InvalidKeyLengthError {
-                .try_into()
+                expected: 32,
-                .map_err(|v: Vec<u8>| StorageError::InvalidKeyLength {
+                actual: v.len(),
-                    expected: 32,
+            })
-                    actual: v.len(),
+        })?;
-                })?;
         Ok(ed25519_dalek::SigningKey::from_bytes(&raw))
     }
 }
@@ -46,7 +43,7 @@ impl FileSigningKeyStorage {
 impl SigningKeyStorage for FileSigningKeyStorage {
     fn load_or_create(&self) -> std::result::Result<ed25519_dalek::SigningKey, StorageError> {
         if let Some(parent) = self.path.parent() {
-            std::fs::create_dir_all(parent)?;
+            std::fs::create_dir_all(parent).map_err(OneOf::new)?;
         }
 
         if self.path.exists() {
@@ -64,20 +61,21 @@ impl SigningKeyStorage for FileSigningKeyStorage {
         {
             Ok(mut file) => {
                 use std::io::Write as _;
-                file.write_all(&raw_key)?;
+                file.write_all(&raw_key).map_err(OneOf::new)?;
                 Ok(key)
             }
             Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {
                 Self::read_key(&self.path)
             }
-            Err(err) => Err(StorageError::Io(err)),
+            Err(err) => Err(OneOf::new(err)),
         }
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::{FileSigningKeyStorage, SigningKeyStorage, StorageError};
+    use super::{FileSigningKeyStorage, SigningKeyStorage};
+    use crate::errors::InvalidKeyLengthError;
 
     fn unique_temp_key_path() -> std::path::PathBuf {
         let nanos = std::time::SystemTime::now()
@@ -119,12 +117,12 @@ mod tests {
             .load_or_create()
             .expect_err("storage should reject non-32-byte key file");
 
-        match err {
+        match err.narrow::<InvalidKeyLengthError, _>() {
-            StorageError::InvalidKeyLength { expected, actual } => {
+            Ok(invalid_len) => {
-                assert_eq!(expected, 32);
+                assert_eq!(invalid_len.expected, 32);
-                assert_eq!(actual, 31);
+                assert_eq!(invalid_len.actual, 31);
             }
-            other => panic!("unexpected error: {other:?}"),
+            Err(other) => panic!("unexpected io error: {other:?}"),
         }
 
         std::fs::remove_file(path).expect("temp key file should be removable");

server/crates/arbiter-client/src/transport.rs

@@ -1,7 +1,12 @@
 use arbiter_proto::proto::client::{ClientRequest, ClientResponse};
 use std::sync::atomic::{AtomicI32, Ordering};
+use terrors::OneOf;
 use tokio::sync::mpsc;
 
+use crate::errors::{
+    ClientTransportError, TransportChannelClosedError, TransportConnectionClosedError,
+};
+
 pub(crate) const BUFFER_LENGTH: usize = 16;
 static NEXT_REQUEST_ID: AtomicI32 = AtomicI32::new(1);
 
@@ -9,15 +14,6 @@ pub(crate) fn next_request_id() -> i32 {
     NEXT_REQUEST_ID.fetch_add(1, Ordering::Relaxed)
 }
 
-#[derive(Debug, thiserror::Error)]
-pub(crate) enum ClientSignError {
-    #[error("Transport channel closed")]
-    ChannelClosed,
-
-    #[error("Connection closed by server")]
-    ConnectionClosed,
-}
-
 pub(crate) struct ClientTransport {
     pub(crate) sender: mpsc::Sender<ClientRequest>,
     pub(crate) receiver: tonic::Streaming<ClientResponse>,
@@ -27,18 +23,20 @@ impl ClientTransport {
     pub(crate) async fn send(
         &mut self,
         request: ClientRequest,
-    ) -> std::result::Result<(), ClientSignError> {
+    ) -> std::result::Result<(), ClientTransportError> {
         self.sender
             .send(request)
             .await
-            .map_err(|_| ClientSignError::ChannelClosed)
+            .map_err(|_| OneOf::new(TransportChannelClosedError))
     }
 
-    pub(crate) async fn recv(&mut self) -> std::result::Result<ClientResponse, ClientSignError> {
+    pub(crate) async fn recv(
+        &mut self,
+    ) -> std::result::Result<ClientResponse, ClientTransportError> {
         match self.receiver.message().await {
             Ok(Some(resp)) => Ok(resp),
-            Ok(None) => Err(ClientSignError::ConnectionClosed),
+            Ok(None) => Err(OneOf::new(TransportConnectionClosedError)),
-            Err(_) => Err(ClientSignError::ConnectionClosed),
+            Err(_) => Err(OneOf::new(TransportConnectionClosedError)),
         }
     }
 }

server/crates/arbiter-client/src/wallets/evm.rs

@@ -2,22 +2,21 @@ use alloy::{
     consensus::SignableTransaction,
     network::TxSigner,
     primitives::{Address, B256, ChainId, Signature},
-    signers::{Error, Result, Signer},
+    signers::{Result, Signer},
 };
 use async_trait::async_trait;
 use std::sync::Arc;
+use terrors::OneOf;
 use tokio::sync::Mutex;
 
-use arbiter_proto::proto::{
+use crate::{
-    client::{
+    errors::{
-        ClientRequest, client_request::Payload as ClientRequestPayload,
+        EvmChainIdMismatchError, EvmHashSigningUnsupportedError,
-        client_response::Payload as ClientResponsePayload,
+        EvmTransactionSigningUnsupportedError, EvmWalletError,
     },
-    evm::evm_sign_transaction_response::Result as EvmSignTransactionResult,
+    transport::ClientTransport,
 };
 
-use crate::transport::{ClientTransport, next_request_id};
-
 pub struct ArbiterEvmWallet {
     transport: Arc<Mutex<ClientTransport>>,
     address: Address,
@@ -25,6 +24,7 @@ pub struct ArbiterEvmWallet {
 }
 
 impl ArbiterEvmWallet {
+    #[allow(dead_code)]
     pub(crate) fn new(transport: Arc<Mutex<ClientTransport>>, address: Address) -> Self {
         Self {
             transport,
@@ -42,14 +42,17 @@ impl ArbiterEvmWallet {
         self
     }
 
-    fn validate_chain_id(&self, tx: &mut dyn SignableTransaction<Signature>) -> Result<()> {
+    fn validate_chain_id(
+        &self,
+        tx: &mut dyn SignableTransaction<Signature>,
+    ) -> std::result::Result<(), EvmWalletError> {
         if let Some(chain_id) = self.chain_id
             && !tx.set_chain_id_checked(chain_id)
         {
-            return Err(Error::TransactionChainIdMismatch {
+            return Err(OneOf::new(EvmChainIdMismatchError {
                 signer: chain_id,
                 tx: tx.chain_id().unwrap(),
-            });
+            }));
         }
 
         Ok(())
@@ -59,9 +62,7 @@ impl ArbiterEvmWallet {
 #[async_trait]
 impl Signer for ArbiterEvmWallet {
     async fn sign_hash(&self, _hash: &B256) -> Result<Signature> {
-        Err(Error::other(
+        Err(EvmWalletError::new(EvmHashSigningUnsupportedError).into())
-            "hash-only signing is not supported for ArbiterEvmWallet; use transaction signing",
-        ))
     }
 
     fn address(&self) -> Address {
@@ -87,61 +88,10 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
         &self,
         tx: &mut dyn SignableTransaction<Signature>,
     ) -> Result<Signature> {
-        self.validate_chain_id(tx)?;
+        let _transport = self.transport.lock().await;
+        self.validate_chain_id(tx)
+            .map_err(OneOf::into::<alloy::signers::Error>)?;
 
-        let mut transport = self.transport.lock().await;
+        Err(EvmWalletError::new(EvmTransactionSigningUnsupportedError).into())
-        let request_id = next_request_id();
-        let rlp_transaction = tx.encoded_for_signing();
-
-        transport
-            .send(ClientRequest {
-                request_id,
-                payload: Some(ClientRequestPayload::EvmSignTransaction(
-                    arbiter_proto::proto::evm::EvmSignTransactionRequest {
-                        wallet_address: self.address.to_vec(),
-                        rlp_transaction,
-                    },
-                )),
-            })
-            .await
-            .map_err(|_| Error::other("failed to send evm sign transaction request"))?;
-
-        let response = transport
-            .recv()
-            .await
-            .map_err(|_| Error::other("failed to receive evm sign transaction response"))?;
-
-        if response.request_id != Some(request_id) {
-            return Err(Error::other(
-                "received mismatched response id for evm sign transaction",
-            ));
-        }
-
-        let payload = response
-            .payload
-            .ok_or_else(|| Error::other("missing evm sign transaction response payload"))?;
-
-        let ClientResponsePayload::EvmSignTransaction(response) = payload else {
-            return Err(Error::other(
-                "unexpected response payload for evm sign transaction request",
-            ));
-        };
-
-        let result = response
-            .result
-            .ok_or_else(|| Error::other("missing evm sign transaction result"))?;
-
-        match result {
-            EvmSignTransactionResult::Signature(signature) => {
-                Signature::try_from(signature.as_slice())
-                    .map_err(|_| Error::other("invalid signature returned by server"))
-            }
-            EvmSignTransactionResult::EvalError(eval_error) => Err(Error::other(format!(
-                "transaction rejected by policy: {eval_error:?}"
-            ))),
-            EvmSignTransactionResult::Error(code) => Err(Error::other(format!(
-                "server failed to sign transaction with error code {code}"
-            ))),
-        }
     }
 }

server/crates/arbiter-server/src/actors/client/auth.rs

@@ -54,19 +54,10 @@ pub enum Outbound {
     AuthSuccess,
 }
 
-#[derive(Debug, Clone)]
-pub struct AuthenticatedClient {
-    pub pubkey: VerifyingKey,
-    pub client_id: i32,
-}
-
 /// Atomically reads and increments the nonce for a known client.
 /// Returns `None` if the pubkey is not registered.
-async fn get_nonce(
+async fn get_nonce(db: &db::DatabasePool, pubkey: &VerifyingKey) -> Result<Option<i32>, Error> {
-    db: &db::DatabasePool,
+    let pubkey_bytes = pubkey.as_bytes().to_vec();
-    pubkey: &VerifyingKey,
-) -> Result<Option<(/* client_id */ i32, /* nonce */ i32)>, Error> {
-    let pubkey_bytes = pubkey.as_bytes();
 
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
@@ -74,6 +65,7 @@ async fn get_nonce(
     })?;
 
     conn.exclusive_transaction(|conn| {
+        let pubkey_bytes = pubkey_bytes.clone();
         Box::pin(async move {
             let Some((client_id, current_nonce)) = program_client::table
                 .filter(program_client::public_key.eq(&pubkey_bytes))
@@ -91,7 +83,8 @@ async fn get_nonce(
                 .execute(conn)
                 .await?;
 
-            Ok(Some((client_id, current_nonce)))
+            let _ = client_id;
+            Ok(Some(current_nonce))
         })
     })
     .await
@@ -220,25 +213,23 @@ where
 pub async fn authenticate<T>(
     props: &mut ClientConnection,
     transport: &mut T,
-) -> Result<AuthenticatedClient, Error>
+) -> Result<VerifyingKey, Error>
 where
     T: Bi<Inbound, Result<Outbound, Error>> + Send + ?Sized,
 {
-    let Some(Inbound::AuthChallengeRequest { pubkey }) = transport.recv().await else {
+    let Some(Inbound::AuthChallengeRequest { pubkey }) = transport.recv().await
+    else {
         return Err(Error::Transport);
     };
 
-    let (client_id, nonce) = match get_nonce(&props.db, &pubkey).await? {
+    let nonce = match get_nonce(&props.db, &pubkey).await? {
-        Some(client_nonce) => client_nonce,
+        Some(nonce) => nonce,
         None => {
             approve_new_client(&props.actors, pubkey).await?;
             match insert_client(&props.db, &pubkey).await? {
-                InsertClientResult::Inserted => match get_nonce(&props.db, &pubkey).await? {
+                InsertClientResult::Inserted => 0,
-                    Some((client_id, _)) => (client_id, 0),
-                    None => return Err(Error::DatabaseOperationFailed),
-                },
                 InsertClientResult::AlreadyExists => match get_nonce(&props.db, &pubkey).await? {
-                    Some((client_id, nonce)) => (client_id, nonce),
+                    Some(nonce) => nonce,
                     None => return Err(Error::DatabaseOperationFailed),
                 },
             }
@@ -254,5 +245,5 @@ where
             Error::Transport
         })?;
 
-    Ok(AuthenticatedClient { pubkey, client_id })
+    Ok(pubkey)
 }

server/crates/arbiter-server/src/actors/client/mod.rs

@@ -10,16 +10,11 @@ use crate::{
 pub struct ClientConnection {
     pub(crate) db: db::DatabasePool,
     pub(crate) actors: GlobalActors,
-    pub(crate) client_id: i32,
 }
 
 impl ClientConnection {
     pub fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
-        Self {
+        Self { db, actors }
-            db,
-            actors,
-            client_id: 0,
-        }
     }
 }
 
@@ -31,8 +26,7 @@ where
     T: Bi<auth::Inbound, Result<auth::Outbound, auth::Error>> + Send + ?Sized,
 {
     match auth::authenticate(&mut props, transport).await {
-        Ok(authenticated) => {
+        Ok(_pubkey) => {
-            props.client_id = authenticated.client_id;
             ClientSession::spawn(ClientSession::new(props));
             info!("Client authenticated, session started");
         }

server/crates/arbiter-server/src/actors/client/session.rs

@@ -1,18 +1,11 @@
 use kameo::{Actor, messages};
 use tracing::error;
 
-use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
-
 use crate::{
     actors::{
-        GlobalActors,
+        GlobalActors, client::ClientConnection, keyholder::KeyHolderState, router::RegisterClient,
-        client::ClientConnection,
-        evm::{ClientSignTransaction, SignTransactionError},
-        keyholder::KeyHolderState,
-        router::RegisterClient,
     },
     db,
-    evm::VetError,
 };
 
 pub struct ClientSession {
@@ -41,34 +34,6 @@ impl ClientSession {
 
         Ok(vault_state)
     }
-
-    #[message]
-    pub(crate) async fn handle_sign_transaction(
-        &mut self,
-        wallet_address: Address,
-        transaction: TxEip1559,
-    ) -> Result<Signature, SignTransactionRpcError> {
-        match self
-            .props
-            .actors
-            .evm
-            .ask(ClientSignTransaction {
-                client_id: self.props.client_id,
-                wallet_address,
-                transaction,
-            })
-            .await
-        {
-            Ok(signature) => Ok(signature),
-            Err(kameo::error::SendError::HandlerError(SignTransactionError::Vet(vet_error))) => {
-                Err(SignTransactionRpcError::Vet(vet_error))
-            }
-            Err(err) => {
-                error!(?err, "Failed to sign EVM transaction in client session");
-                Err(SignTransactionRpcError::Internal)
-            }
-        }
-    }
 }
 
 impl Actor for ClientSession {
@@ -104,12 +69,3 @@ pub enum Error {
     #[error("Internal error")]
     Internal,
 }
-
-#[derive(Debug, thiserror::Error)]
-pub enum SignTransactionRpcError {
-    #[error("Policy evaluation failed")]
-    Vet(#[from] VetError),
-
-    #[error("Internal error")]
-    Internal,
-}

server/crates/arbiter-server/src/actors/user_agent/session.rs

@@ -36,10 +36,7 @@ impl Error {
 pub struct UserAgentSession {
     props: UserAgentConnection,
     state: UserAgentStateMachine<DummyContext>,
-    #[allow(
+    #[allow(dead_code, reason = "The session keeps ownership of the outbound transport even before the state-machine flow starts using it directly")]
-        dead_code,
-        reason = "The session keeps ownership of the outbound transport even before the state-machine flow starts using it directly"
-    )]
     sender: Box<dyn Sender<OutOfBand>>,
 }
 
@@ -47,11 +44,8 @@ mod connection;
 pub(crate) use connection::{
     BootstrapError, HandleBootstrapEncryptedKey, HandleEvmWalletCreate, HandleEvmWalletList,
     HandleGrantCreate, HandleGrantDelete, HandleGrantList, HandleQueryVaultState,
-    HandleSignTransaction,
-};
-pub use connection::{
-    HandleUnsealEncryptedKey, HandleUnsealRequest, SignTransactionError, UnsealError,
 };
+pub use connection::{HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError};
 
 impl UserAgentSession {
     pub(crate) fn new(props: UserAgentConnection, sender: Box<dyn Sender<OutOfBand>>) -> Self {

server/crates/arbiter-server/src/actors/user_agent/session/connection.rs

@@ -1,6 +1,6 @@
 use std::sync::Mutex;
 
-use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
+use alloy::primitives::Address;
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use kameo::error::SendError;
 use kameo::messages;
@@ -14,14 +14,13 @@ use crate::safe_cell::SafeCell;
 use crate::{
     actors::{
         evm::{
-            ClientSignTransaction, Generate, ListWallets, SignTransactionError as EvmSignError,
+            Generate, ListWallets, UseragentCreateGrant, UseragentDeleteGrant, UseragentListGrants,
-            UseragentCreateGrant, UseragentDeleteGrant, UseragentListGrants,
         },
         keyholder::{self, Bootstrap, TryUnseal},
         user_agent::session::{
-            UserAgentSession,
+                UserAgentSession,
-            state::{UnsealContext, UserAgentEvents, UserAgentStates},
+                state::{UnsealContext, UserAgentEvents, UserAgentStates},
-        },
+            },
     },
     safe_cell::SafeCellHandle as _,
 };
@@ -104,15 +103,6 @@ pub enum BootstrapError {
     General(#[from] super::Error),
 }
 
-#[derive(Debug, Error)]
-pub enum SignTransactionError {
-    #[error("Policy evaluation failed")]
-    Vet(#[from] crate::evm::VetError),
-
-    #[error("Internal signing error")]
-    Internal,
-}
-
 #[messages]
 impl UserAgentSession {
     #[message]
@@ -361,33 +351,4 @@ impl UserAgentSession {
             }
         }
     }
-
-    #[message]
-    pub(crate) async fn handle_sign_transaction(
-        &mut self,
-        client_id: i32,
-        wallet_address: Address,
-        transaction: TxEip1559,
-    ) -> Result<Signature, SignTransactionError> {
-        match self
-            .props
-            .actors
-            .evm
-            .ask(ClientSignTransaction {
-                client_id,
-                wallet_address,
-                transaction,
-            })
-            .await
-        {
-            Ok(signature) => Ok(signature),
-            Err(SendError::HandlerError(EvmSignError::Vet(vet_error))) => {
-                Err(SignTransactionError::Vet(vet_error))
-            }
-            Err(err) => {
-                error!(?err, "EVM sign transaction failed in user-agent session");
-                Err(SignTransactionError::Internal)
-            }
-        }
-    }
 }

server/crates/arbiter-server/src/evm/policies/ether_transfer/mod.rs

@@ -36,8 +36,8 @@ use super::{DatabaseID, EvalContext, EvalViolation};
 // Plain ether transfer
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Meaning {
-    pub(crate) to: Address,
+    to: Address,
-    pub(crate) value: U256,
+    value: U256,
 }
 impl Display for Meaning {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

server/crates/arbiter-server/src/evm/policies/token_transfers/mod.rs

@@ -38,9 +38,9 @@ fn grant_join() -> _ {
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Meaning {
-    pub(crate) token: &'static TokenInfo,
+    token: &'static TokenInfo,
-    pub(crate) to: Address,
+    to: Address,
-    pub(crate) value: U256,
+    value: U256,
 }
 impl std::fmt::Display for Meaning {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

server/crates/arbiter-server/src/grpc/client.rs

@@ -1,5 +1,4 @@
 use arbiter_proto::{
-    google::protobuf::Empty as ProtoEmpty,
     proto::client::{
         ClientRequest, ClientResponse, VaultState as ProtoVaultState,
         client_request::Payload as ClientRequestPayload,
@@ -18,135 +17,16 @@ use crate::{
     actors::{
         client::{
             self, ClientConnection,
-            session::{
+            session::{ClientSession, Error, HandleQueryVaultState},
-                ClientSession, Error, HandleQueryVaultState, HandleSignTransaction,
-                SignTransactionRpcError,
-            },
         },
         keyholder::KeyHolderState,
     },
-    evm::{PolicyError, VetError, policies::EvalViolation},
     grpc::request_tracker::RequestTracker,
     utils::defer,
 };
 
-use alloy::{
-    consensus::TxEip1559,
-    primitives::{Address, U256},
-    rlp::Decodable,
-};
-use arbiter_proto::proto::evm::{
-    EvmError as ProtoEvmError, EvmSignTransactionResponse, EvalViolation as ProtoEvalViolation,
-    GasLimitExceededViolation, NoMatchingGrantError, PolicyViolationsError,
-    SpecificMeaning as ProtoSpecificMeaning, TokenInfo as ProtoTokenInfo,
-    TransactionEvalError,
-    evm_sign_transaction_response::Result as EvmSignTransactionResult,
-    eval_violation::Kind as ProtoEvalViolationKind,
-    specific_meaning::Meaning as ProtoSpecificMeaningKind,
-    transaction_eval_error::Kind as ProtoTransactionEvalErrorKind,
-};
-
 mod auth;
 
-fn u256_to_proto_bytes(value: U256) -> Vec<u8> {
-    value.to_be_bytes::<32>().to_vec()
-}
-
-fn meaning_to_proto(meaning: crate::evm::policies::SpecificMeaning) -> ProtoSpecificMeaning {
-    let kind = match meaning {
-        crate::evm::policies::SpecificMeaning::EtherTransfer(meaning) => {
-            ProtoSpecificMeaningKind::EtherTransfer(arbiter_proto::proto::evm::EtherTransferMeaning {
-                to: meaning.to.to_vec(),
-                value: u256_to_proto_bytes(meaning.value),
-            })
-        }
-        crate::evm::policies::SpecificMeaning::TokenTransfer(meaning) => {
-            ProtoSpecificMeaningKind::TokenTransfer(arbiter_proto::proto::evm::TokenTransferMeaning {
-                token: Some(ProtoTokenInfo {
-                    symbol: meaning.token.symbol.to_string(),
-                    address: meaning.token.contract.to_vec(),
-                    chain_id: meaning.token.chain,
-                }),
-                to: meaning.to.to_vec(),
-                value: u256_to_proto_bytes(meaning.value),
-            })
-        }
-    };
-
-    ProtoSpecificMeaning {
-        meaning: Some(kind),
-    }
-}
-
-fn violation_to_proto(violation: EvalViolation) -> ProtoEvalViolation {
-    let kind = match violation {
-        EvalViolation::InvalidTarget { target } => ProtoEvalViolationKind::InvalidTarget(target.to_vec()),
-        EvalViolation::GasLimitExceeded {
-            max_gas_fee_per_gas,
-            max_priority_fee_per_gas,
-        } => ProtoEvalViolationKind::GasLimitExceeded(GasLimitExceededViolation {
-            max_gas_fee_per_gas: max_gas_fee_per_gas.map(u256_to_proto_bytes),
-            max_priority_fee_per_gas: max_priority_fee_per_gas.map(u256_to_proto_bytes),
-        }),
-        EvalViolation::RateLimitExceeded => ProtoEvalViolationKind::RateLimitExceeded(ProtoEmpty {}),
-        EvalViolation::VolumetricLimitExceeded => {
-            ProtoEvalViolationKind::VolumetricLimitExceeded(ProtoEmpty {})
-        }
-        EvalViolation::InvalidTime => ProtoEvalViolationKind::InvalidTime(ProtoEmpty {}),
-        EvalViolation::InvalidTransactionType => {
-            ProtoEvalViolationKind::InvalidTransactionType(ProtoEmpty {})
-        }
-    };
-
-    ProtoEvalViolation { kind: Some(kind) }
-}
-
-fn eval_error_to_proto(err: VetError) -> Option<TransactionEvalError> {
-    let kind = match err {
-        VetError::ContractCreationNotSupported => {
-            ProtoTransactionEvalErrorKind::ContractCreationNotSupported(ProtoEmpty {})
-        }
-        VetError::UnsupportedTransactionType => {
-            ProtoTransactionEvalErrorKind::UnsupportedTransactionType(ProtoEmpty {})
-        }
-        VetError::Evaluated(meaning, policy_error) => match policy_error {
-            PolicyError::NoMatchingGrant => {
-                ProtoTransactionEvalErrorKind::NoMatchingGrant(NoMatchingGrantError {
-                    meaning: Some(meaning_to_proto(meaning)),
-                })
-            }
-            PolicyError::Violations(violations) => {
-                ProtoTransactionEvalErrorKind::PolicyViolations(PolicyViolationsError {
-                    meaning: Some(meaning_to_proto(meaning)),
-                    violations: violations.into_iter().map(violation_to_proto).collect(),
-                })
-            }
-            PolicyError::Pool(_) | PolicyError::Database(_) => {
-                return None;
-            }
-        },
-    };
-
-    Some(TransactionEvalError { kind: Some(kind) })
-}
-
-fn decode_eip1559_transaction(payload: &[u8]) -> Result<TxEip1559, ()> {
-    let mut body = payload;
-    if let Some((prefix, rest)) = payload.split_first()
-        && *prefix == 0x02
-    {
-        body = rest;
-    }
-
-    let mut cursor = body;
-    let transaction = TxEip1559::decode(&mut cursor).map_err(|_| ())?;
-    if !cursor.is_empty() {
-        return Err(());
-    }
-
-    Ok(transaction)
-}
-
 async fn dispatch_loop(
     mut bi: GrpcBi<ClientRequest, ClientResponse>,
     actor: ActorRef<ClientSession>,
@@ -210,64 +90,6 @@ async fn dispatch_conn_message(
             }
             .into(),
         ),
-        ClientRequestPayload::EvmSignTransaction(request) => {
-            let wallet_address = match <[u8; 20]>::try_from(request.wallet_address.as_slice()) {
-                Ok(address) => Address::from(address),
-                Err(_) => {
-                    let _ = bi
-                        .send(Err(Status::invalid_argument("Invalid EVM wallet address")))
-                        .await;
-                    return Err(());
-                }
-            };
-
-            let transaction = match decode_eip1559_transaction(&request.rlp_transaction) {
-                Ok(transaction) => transaction,
-                Err(()) => {
-                    let _ = bi
-                        .send(Err(Status::invalid_argument(
-                            "Invalid EIP-1559 RLP transaction",
-                        )))
-                        .await;
-                    return Err(());
-                }
-            };
-
-            let response = match actor
-                .ask(HandleSignTransaction {
-                    wallet_address,
-                    transaction,
-                })
-                .await
-            {
-                Ok(signature) => EvmSignTransactionResponse {
-                    result: Some(EvmSignTransactionResult::Signature(signature.as_bytes().to_vec())),
-                },
-                Err(kameo::error::SendError::HandlerError(SignTransactionRpcError::Vet(vet_error))) => {
-                    match eval_error_to_proto(vet_error) {
-                        Some(eval_error) => EvmSignTransactionResponse {
-                            result: Some(EvmSignTransactionResult::EvalError(eval_error)),
-                        },
-                        None => EvmSignTransactionResponse {
-                            result: Some(EvmSignTransactionResult::Error(ProtoEvmError::Internal.into())),
-                        },
-                    }
-                }
-                Err(kameo::error::SendError::HandlerError(SignTransactionRpcError::Internal)) => {
-                    EvmSignTransactionResponse {
-                        result: Some(EvmSignTransactionResult::Error(ProtoEvmError::Internal.into())),
-                    }
-                }
-                Err(err) => {
-                    warn!(error = ?err, "Failed to sign EVM transaction");
-                    EvmSignTransactionResponse {
-                        result: Some(EvmSignTransactionResult::Error(ProtoEvmError::Internal.into())),
-                    }
-                }
-            };
-
-            ClientResponsePayload::EvmSignTransaction(response)
-        }
         payload => {
             warn!(?payload, "Unsupported post-auth client request");
             let _ = bi

server/crates/arbiter-server/src/grpc/client/auth.rs

@@ -151,9 +151,7 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
             _ => {
                 let _ = self
                     .bi
-                    .send(Err(Status::invalid_argument(
+                    .send(Err(Status::invalid_argument("Unsupported client auth request")))
-                        "Unsupported client auth request",
-                    )))
                     .await;
                 None
             }
@@ -170,7 +168,6 @@ pub async fn start(
     response_id: &mut Option<i32>,
 ) -> Result<(), auth::Error> {
     let mut transport = AuthTransportAdapter::new(bi, request_tracker, response_id);
-    let authenticated = client::auth::authenticate(conn, &mut transport).await?;
+    client::auth::authenticate(conn, &mut transport).await?;
-    conn.client_id = authenticated.client_id;
     Ok(())
 }

server/crates/arbiter-server/src/grpc/user_agent.rs

@@ -4,24 +4,17 @@ use arbiter_proto::{
     google::protobuf::{Empty as ProtoEmpty, Timestamp as ProtoTimestamp},
     proto::{
         evm::{
-            EtherTransferSettings as ProtoEtherTransferSettings,
+            EtherTransferSettings as ProtoEtherTransferSettings, EvmError as ProtoEvmError,
-            EvalViolation as ProtoEvalViolation, EvmError as ProtoEvmError, EvmGrantCreateRequest,
+            EvmGrantCreateRequest, EvmGrantCreateResponse, EvmGrantDeleteRequest,
-            EvmGrantCreateResponse, EvmGrantDeleteRequest, EvmGrantDeleteResponse, EvmGrantList,
+            EvmGrantDeleteResponse, EvmGrantList, EvmGrantListResponse, GrantEntry,
-            EvmGrantListResponse, EvmSignTransactionResponse, GasLimitExceededViolation,
-            GrantEntry, NoMatchingGrantError, PolicyViolationsError,
             SharedSettings as ProtoSharedSettings, SpecificGrant as ProtoSpecificGrant,
-            SpecificMeaning as ProtoSpecificMeaning, TokenInfo as ProtoTokenInfo,
+            TokenTransferSettings as ProtoTokenTransferSettings,
-            TokenTransferSettings as ProtoTokenTransferSettings, TransactionEvalError,
             TransactionRateLimit as ProtoTransactionRateLimit,
             VolumeRateLimit as ProtoVolumeRateLimit, WalletCreateResponse, WalletEntry, WalletList,
-            WalletListResponse, eval_violation::Kind as ProtoEvalViolationKind,
+            WalletListResponse, evm_grant_create_response::Result as EvmGrantCreateResult,
-            evm_grant_create_response::Result as EvmGrantCreateResult,
             evm_grant_delete_response::Result as EvmGrantDeleteResult,
             evm_grant_list_response::Result as EvmGrantListResult,
-            evm_sign_transaction_response::Result as EvmSignTransactionResult,
             specific_grant::Grant as ProtoSpecificGrantType,
-            specific_meaning::Meaning as ProtoSpecificMeaningKind,
-            transaction_eval_error::Kind as ProtoTransactionEvalErrorKind,
             wallet_create_response::Result as WalletCreateResult,
             wallet_list_response::Result as WalletListResult,
         },
@@ -30,8 +23,8 @@ use arbiter_proto::{
             BootstrapResult as ProtoBootstrapResult,
             SdkClientConnectionResponse as ProtoSdkClientConnectionResponse,
             UnsealEncryptedKey as ProtoUnsealEncryptedKey, UnsealResult as ProtoUnsealResult,
-            UnsealStart, UserAgentEvmSignTransactionRequest, UserAgentRequest, UserAgentResponse,
+            UnsealStart, UserAgentRequest, UserAgentResponse, VaultState as ProtoVaultState,
-            VaultState as ProtoVaultState, user_agent_request::Payload as UserAgentRequestPayload,
+            user_agent_request::Payload as UserAgentRequestPayload,
             user_agent_response::Payload as UserAgentResponsePayload,
         },
     },
@@ -54,9 +47,7 @@ use crate::{
             session::{
                 BootstrapError, Error, HandleBootstrapEncryptedKey, HandleEvmWalletCreate,
                 HandleEvmWalletList, HandleGrantCreate, HandleGrantDelete, HandleGrantList,
-                HandleQueryVaultState, HandleSignTransaction, HandleUnsealEncryptedKey,
+                HandleQueryVaultState, HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError,
-                HandleUnsealRequest, SignTransactionError as SessionSignTransactionError,
-                UnsealError,
             },
         },
     },
@@ -64,124 +55,12 @@ use crate::{
         Grant, SharedGrantSettings, SpecificGrant, TransactionRateLimit, VolumeRateLimit,
         ether_transfer, token_transfers,
     },
-    evm::{PolicyError, VetError, policies::EvalViolation},
     grpc::request_tracker::RequestTracker,
     utils::defer,
 };
-use alloy::{
+use alloy::primitives::{Address, U256};
-    consensus::TxEip1559,
-    primitives::{Address, U256},
-    rlp::Decodable,
-};
 mod auth;
 
-fn u256_to_proto_bytes(value: U256) -> Vec<u8> {
-    value.to_be_bytes::<32>().to_vec()
-}
-
-fn meaning_to_proto(meaning: crate::evm::policies::SpecificMeaning) -> ProtoSpecificMeaning {
-    let kind = match meaning {
-        crate::evm::policies::SpecificMeaning::EtherTransfer(meaning) => {
-            ProtoSpecificMeaningKind::EtherTransfer(
-                arbiter_proto::proto::evm::EtherTransferMeaning {
-                    to: meaning.to.to_vec(),
-                    value: u256_to_proto_bytes(meaning.value),
-                },
-            )
-        }
-        crate::evm::policies::SpecificMeaning::TokenTransfer(meaning) => {
-            ProtoSpecificMeaningKind::TokenTransfer(
-                arbiter_proto::proto::evm::TokenTransferMeaning {
-                    token: Some(ProtoTokenInfo {
-                        symbol: meaning.token.symbol.to_string(),
-                        address: meaning.token.contract.to_vec(),
-                        chain_id: meaning.token.chain,
-                    }),
-                    to: meaning.to.to_vec(),
-                    value: u256_to_proto_bytes(meaning.value),
-                },
-            )
-        }
-    };
-
-    ProtoSpecificMeaning {
-        meaning: Some(kind),
-    }
-}
-
-fn violation_to_proto(violation: EvalViolation) -> ProtoEvalViolation {
-    let kind = match violation {
-        EvalViolation::InvalidTarget { target } => {
-            ProtoEvalViolationKind::InvalidTarget(target.to_vec())
-        }
-        EvalViolation::GasLimitExceeded {
-            max_gas_fee_per_gas,
-            max_priority_fee_per_gas,
-        } => ProtoEvalViolationKind::GasLimitExceeded(GasLimitExceededViolation {
-            max_gas_fee_per_gas: max_gas_fee_per_gas.map(u256_to_proto_bytes),
-            max_priority_fee_per_gas: max_priority_fee_per_gas.map(u256_to_proto_bytes),
-        }),
-        EvalViolation::RateLimitExceeded => {
-            ProtoEvalViolationKind::RateLimitExceeded(ProtoEmpty {})
-        }
-        EvalViolation::VolumetricLimitExceeded => {
-            ProtoEvalViolationKind::VolumetricLimitExceeded(ProtoEmpty {})
-        }
-        EvalViolation::InvalidTime => ProtoEvalViolationKind::InvalidTime(ProtoEmpty {}),
-        EvalViolation::InvalidTransactionType => {
-            ProtoEvalViolationKind::InvalidTransactionType(ProtoEmpty {})
-        }
-    };
-
-    ProtoEvalViolation { kind: Some(kind) }
-}
-
-fn eval_error_to_proto(err: VetError) -> Option<TransactionEvalError> {
-    let kind = match err {
-        VetError::ContractCreationNotSupported => {
-            ProtoTransactionEvalErrorKind::ContractCreationNotSupported(ProtoEmpty {})
-        }
-        VetError::UnsupportedTransactionType => {
-            ProtoTransactionEvalErrorKind::UnsupportedTransactionType(ProtoEmpty {})
-        }
-        VetError::Evaluated(meaning, policy_error) => match policy_error {
-            PolicyError::NoMatchingGrant => {
-                ProtoTransactionEvalErrorKind::NoMatchingGrant(NoMatchingGrantError {
-                    meaning: Some(meaning_to_proto(meaning)),
-                })
-            }
-            PolicyError::Violations(violations) => {
-                ProtoTransactionEvalErrorKind::PolicyViolations(PolicyViolationsError {
-                    meaning: Some(meaning_to_proto(meaning)),
-                    violations: violations.into_iter().map(violation_to_proto).collect(),
-                })
-            }
-            PolicyError::Pool(_) | PolicyError::Database(_) => {
-                return None;
-            }
-        },
-    };
-
-    Some(TransactionEvalError { kind: Some(kind) })
-}
-
-fn decode_eip1559_transaction(payload: &[u8]) -> Result<TxEip1559, ()> {
-    let mut body = payload;
-    if let Some((prefix, rest)) = payload.split_first()
-        && *prefix == 0x02
-    {
-        body = rest;
-    }
-
-    let mut cursor = body;
-    let transaction = TxEip1559::decode(&mut cursor).map_err(|_| ())?;
-    if !cursor.is_empty() {
-        return Err(());
-    }
-
-    Ok(transaction)
-}
-
 pub struct OutOfBandAdapter(mpsc::Sender<OutOfBand>);
 
 #[async_trait]
@@ -392,92 +271,6 @@ async fn dispatch_conn_message(
                 actor.ask(HandleGrantDelete { grant_id }).await,
             ))
         }
-        UserAgentRequestPayload::EvmSignTransaction(UserAgentEvmSignTransactionRequest {
-            client_id,
-            request,
-        }) => {
-            if client_id <= 0 {
-                let _ = bi
-                    .send(Err(Status::invalid_argument("Invalid SDK client id")))
-                    .await;
-                return Err(());
-            }
-
-            let Some(request) = request else {
-                let _ = bi
-                    .send(Err(Status::invalid_argument(
-                        "Missing EVM sign transaction payload",
-                    )))
-                    .await;
-                return Err(());
-            };
-
-            let wallet_address = match <[u8; 20]>::try_from(request.wallet_address.as_slice()) {
-                Ok(address) => Address::from(address),
-                Err(_) => {
-                    let _ = bi
-                        .send(Err(Status::invalid_argument("Invalid EVM wallet address")))
-                        .await;
-                    return Err(());
-                }
-            };
-
-            let transaction = match decode_eip1559_transaction(&request.rlp_transaction) {
-                Ok(transaction) => transaction,
-                Err(()) => {
-                    let _ = bi
-                        .send(Err(Status::invalid_argument(
-                            "Invalid EIP-1559 RLP transaction",
-                        )))
-                        .await;
-                    return Err(());
-                }
-            };
-
-            let response = match actor
-                .ask(HandleSignTransaction {
-                    client_id,
-                    wallet_address,
-                    transaction,
-                })
-                .await
-            {
-                Ok(signature) => EvmSignTransactionResponse {
-                    result: Some(EvmSignTransactionResult::Signature(
-                        signature.as_bytes().to_vec(),
-                    )),
-                },
-                Err(SendError::HandlerError(SessionSignTransactionError::Vet(vet_error))) => {
-                    match eval_error_to_proto(vet_error) {
-                        Some(eval_error) => EvmSignTransactionResponse {
-                            result: Some(EvmSignTransactionResult::EvalError(eval_error)),
-                        },
-                        None => EvmSignTransactionResponse {
-                            result: Some(EvmSignTransactionResult::Error(
-                                ProtoEvmError::Internal.into(),
-                            )),
-                        },
-                    }
-                }
-                Err(SendError::HandlerError(SessionSignTransactionError::Internal)) => {
-                    EvmSignTransactionResponse {
-                        result: Some(EvmSignTransactionResult::Error(
-                            ProtoEvmError::Internal.into(),
-                        )),
-                    }
-                }
-                Err(err) => {
-                    warn!(error = ?err, "Failed to sign EVM transaction via user-agent");
-                    EvmSignTransactionResponse {
-                        result: Some(EvmSignTransactionResult::Error(
-                            ProtoEvmError::Internal.into(),
-                        )),
-                    }
-                }
-            };
-
-            UserAgentResponsePayload::EvmSignTransaction(response)
-        }
         payload => {
             warn!(?payload, "Unsupported post-auth user agent request");
             let _ = bi