diff --git a/server/Cargo.lock b/server/Cargo.lock
index f6ab9b4..8f72a04 100644
--- a/server/Cargo.lock
+++ b/server/Cargo.lock
@@ -59,6 +59,7 @@ version = "0.1.0"
 name = "arbiter-proto"
 version = "0.1.0"
 dependencies = [
+ "async-trait",
  "base64",
  "futures",
  "hex",
@@ -122,6 +123,7 @@ name = "arbiter-useragent"
 version = "0.1.0"
 dependencies = [
  "arbiter-proto",
+ "async-trait",
  "ed25519-dalek",
  "http",
  "kameo",
diff --git a/server/crates/arbiter-proto/Cargo.toml b/server/crates/arbiter-proto/Cargo.toml
index 006e406..0673f8a 100644
--- a/server/crates/arbiter-proto/Cargo.toml
+++ b/server/crates/arbiter-proto/Cargo.toml
@@ -20,6 +20,7 @@ rustls-pki-types.workspace = true
 base64 = "0.22.1"
 prost-types.workspace = true
 tracing.workspace = true
+async-trait.workspace = true
 
 [build-dependencies]
 tonic-prost-build = "0.14.3"
diff --git a/server/crates/arbiter-proto/src/transport.rs b/server/crates/arbiter-proto/src/transport.rs
index 48bb9a3..02ae72c 100644
--- a/server/crates/arbiter-proto/src/transport.rs
+++ b/server/crates/arbiter-proto/src/transport.rs
@@ -76,6 +76,8 @@
 
 use std::marker::PhantomData;
 
+use async_trait::async_trait;
+
 /// Errors returned by transport adapters implementing [`Bi`].
 pub enum Error {
     /// The outbound side of the transport is no longer accepting messages.
@@ -87,13 +89,11 @@ pub enum Error {
 /// `Bi<Inbound, Outbound>` models a duplex channel with:
 /// - inbound items of type `Inbound` read via [`Bi::recv`]
 /// - outbound items of type `Outbound` written via [`Bi::send`]
+#[async_trait]
 pub trait Bi<Inbound, Outbound>: Send + Sync + 'static {
-    fn send(
-        &mut self,
-        item: Outbound,
-    ) -> impl std::future::Future<Output = Result<(), Error>> + Send;
+    async fn send(&mut self, item: Outbound) -> Result<(), Error>;
 
-    fn recv(&mut self) -> impl std::future::Future<Output = Option<Inbound>> + Send;
+    async fn recv(&mut self) -> Option<Inbound>;
 }
 
 /// Converts transport-facing inbound items into protocol-facing inbound items.
@@ -176,6 +176,7 @@ where
 
 /// gRPC-specific transport adapters and helpers.
 pub mod grpc {
+    use async_trait::async_trait;
     use futures::StreamExt;
     use tokio::sync::mpsc;
     use tonic::Streaming;
@@ -199,7 +200,6 @@ pub mod grpc {
         outbound_converter: OutboundConverter,
     }
 
-
     impl<InboundTransport, Inbound, InboundConverter, OutboundConverter>
         GrpcAdapter<InboundConverter, OutboundConverter>
     where
@@ -221,8 +221,8 @@ pub mod grpc {
         }
     }
 
-
-    impl< InboundConverter, OutboundConverter> Bi<InboundConverter::Output, OutboundConverter::Input>
+    #[async_trait]
+    impl<InboundConverter, OutboundConverter> Bi<InboundConverter::Output, OutboundConverter::Input>
         for GrpcAdapter<InboundConverter, OutboundConverter>
     where
         InboundConverter: RecvConverter,
@@ -275,6 +275,7 @@ impl<Inbound, Outbound> Default for DummyTransport<Inbound, Outbound> {
     }
 }
 
+#[async_trait]
 impl<Inbound, Outbound> Bi<Inbound, Outbound> for DummyTransport<Inbound, Outbound>
 where
     Inbound: Send + Sync + 'static,
@@ -284,10 +285,8 @@ where
         Ok(())
     }
 
-    fn recv(&mut self) -> impl std::future::Future<Output = Option<Inbound>> + Send {
-        async {
-            std::future::pending::<()>().await;
-            None
-        }
+    async fn recv(&mut self) -> Option<Inbound> {
+        std::future::pending::<()>().await;
+        None
     }
 }
diff --git a/server/crates/arbiter-server/src/actors/client/mod.rs b/server/crates/arbiter-server/src/actors/client/mod.rs
index 8698abb..405bd54 100644
--- a/server/crates/arbiter-server/src/actors/client/mod.rs
+++ b/server/crates/arbiter-server/src/actors/client/mod.rs
@@ -1,8 +1,7 @@
 use arbiter_proto::{
     proto::client::{
         AuthChallenge, AuthChallengeRequest, AuthChallengeSolution, AuthOk, ClientRequest,
-        ClientResponse,
-        client_request::Payload as ClientRequestPayload,
+        ClientResponse, client_request::Payload as ClientRequestPayload,
         client_response::Payload as ClientResponsePayload,
     },
     transport::{Bi, DummyTransport},
@@ -50,19 +49,15 @@ pub enum ClientError {
     DatabaseOperationFailed,
 }
 
-pub struct ClientActor<Transport>
-where
-    Transport: Bi<ClientRequest, Result<ClientResponse, ClientError>>,
-{
+pub type Transport = Box<dyn Bi<ClientRequest, Result<ClientResponse, ClientError>> + Send>;
+
+pub struct ClientActor {
     db: db::DatabasePool,
     state: ClientStateMachine<DummyContext>,
     transport: Transport,
 }
 
-impl<Transport> ClientActor<Transport>
-where
-    Transport: Bi<ClientRequest, Result<ClientResponse, ClientError>>,
-{
+impl ClientActor {
     pub(crate) fn new(context: ServerContext, transport: Transport) -> Self {
         Self {
             db: context.db.clone(),
@@ -197,10 +192,7 @@ where
         Ok((valid, challenge_context))
     }
 
-    async fn handle_auth_challenge_solution(
-        &mut self,
-        solution: AuthChallengeSolution,
-    ) -> Output {
+    async fn handle_auth_challenge_solution(&mut self, solution: AuthChallengeSolution) -> Output {
         let (valid, challenge_context) = self.verify_challenge_solution(&solution)?;
 
         if valid {
@@ -226,10 +218,7 @@ fn response(payload: ClientResponsePayload) -> ClientResponse {
     }
 }
 
-impl<Transport> Actor for ClientActor<Transport>
-where
-    Transport: Bi<ClientRequest, Result<ClientResponse, ClientError>>,
-{
+impl Actor for ClientActor {
     type Args = Self;
 
     type Error = ();
@@ -278,12 +267,12 @@ where
     }
 }
 
-impl ClientActor<DummyTransport<ClientRequest, Result<ClientResponse, ClientError>>> {
+impl ClientActor {
     pub fn new_manual(db: db::DatabasePool) -> Self {
         Self {
             db,
             state: ClientStateMachine::new(DummyContext),
-            transport: DummyTransport::new(),
+            transport: Box::new(DummyTransport::new()),
         }
     }
 }
diff --git a/server/crates/arbiter-server/src/actors/user_agent/mod.rs b/server/crates/arbiter-server/src/actors/user_agent/mod.rs
index ba801ee..762ae6d 100644
--- a/server/crates/arbiter-server/src/actors/user_agent/mod.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/mod.rs
@@ -71,9 +71,9 @@ pub enum UserAgentError {
     DatabaseOperationFailed,
 }
 
-pub struct UserAgentActor<Transport>
-where
-    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
+pub type Transport = Box<dyn Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>> + Send>;
+
+pub struct UserAgentActor
 {
     db: db::DatabasePool,
     actors: GlobalActors,
@@ -81,10 +81,7 @@ where
     transport: Transport,
 }
 
-impl<Transport> UserAgentActor<Transport>
-where
-    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
-{
+impl UserAgentActor {
     pub(crate) fn new(context: ServerContext, transport: Transport) -> Self {
         Self {
             db: context.db.clone(),
@@ -265,10 +262,7 @@ fn response(payload: UserAgentResponsePayload) -> UserAgentResponse {
     }
 }
 
-impl<Transport> UserAgentActor<Transport>
-where
-    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
-{
+impl UserAgentActor {
     async fn handle_unseal_request(&mut self, req: UnsealStart) -> Output {
         let secret = EphemeralSecret::random();
         let public_key = PublicKey::from(&secret);
@@ -413,10 +407,7 @@ where
 }
 
 
-impl<Transport> Actor for UserAgentActor<Transport>
-where
-    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
-{
+impl Actor for UserAgentActor {
     type Args = Self;
 
     type Error = ();
@@ -466,13 +457,13 @@ where
 }
 
 
-impl UserAgentActor<DummyTransport<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>> {
+impl UserAgentActor {
     pub fn new_manual(db: db::DatabasePool, actors: GlobalActors) -> Self {
         Self {
             db,
             actors,
             state: UserAgentStateMachine::new(DummyContext),
-            transport: DummyTransport::new(),
+            transport: Box::new(DummyTransport::new()),
         }
     }
 }
diff --git a/server/crates/arbiter-server/src/lib.rs b/server/crates/arbiter-server/src/lib.rs
index e6cb5c5..a7b5ebe 100644
--- a/server/crates/arbiter-server/src/lib.rs
+++ b/server/crates/arbiter-server/src/lib.rs
@@ -170,7 +170,7 @@ impl arbiter_proto::proto::arbiter_service_server::ArbiterService for Server {
             IdentityRecvConverter::<ClientRequest>::new(),
             ClientGrpcSender,
         );
-        ClientActor::spawn(ClientActor::new(self.context.clone(), transport));
+        ClientActor::spawn(ClientActor::new(self.context.clone(), Box::new(transport)));
 
         info!(event = "connection established", "grpc.client");
 
@@ -191,7 +191,7 @@ impl arbiter_proto::proto::arbiter_service_server::ArbiterService for Server {
             IdentityRecvConverter::<UserAgentRequest>::new(),
             UserAgentGrpcSender,
         );
-        UserAgentActor::spawn(UserAgentActor::new(self.context.clone(), transport));
+        UserAgentActor::spawn(UserAgentActor::new(self.context.clone(), Box::new(transport)));
 
         info!(event = "connection established", "grpc.user_agent");
 
diff --git a/server/crates/arbiter-server/tests/user_agent/unseal.rs b/server/crates/arbiter-server/tests/user_agent/unseal.rs
index 9128a6c..b0f5d1c 100644
--- a/server/crates/arbiter-server/tests/user_agent/unseal.rs
+++ b/server/crates/arbiter-server/tests/user_agent/unseal.rs
@@ -1,10 +1,9 @@
 use arbiter_proto::proto::user_agent::{
     AuthChallengeRequest, UnsealEncryptedKey, UnsealResult, UnsealStart,
-    UserAgentRequest, UserAgentResponse,
+    UserAgentRequest,
     user_agent_request::Payload as UserAgentRequestPayload,
     user_agent_response::Payload as UserAgentResponsePayload,
 };
-use arbiter_proto::transport::DummyTransport;
 use arbiter_server::{
     actors::{
         GlobalActors,
@@ -18,14 +17,12 @@ use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use memsafe::MemSafe;
 use x25519_dalek::{EphemeralSecret, PublicKey};
 
-type TestUserAgent =
-    UserAgentActor<DummyTransport<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>>;
 
 async fn setup_authenticated_user_agent(
     seal_key: &[u8],
 ) -> (
     arbiter_server::db::DatabasePool,
-    TestUserAgent,
+    UserAgentActor,
 ) {
     let db = db::create_test_pool().await;
 
@@ -59,7 +56,7 @@ async fn setup_authenticated_user_agent(
 }
 
 async fn client_dh_encrypt(
-    user_agent: &mut TestUserAgent,
+    user_agent: &mut UserAgentActor,
     key_to_send: &[u8],
 ) -> UnsealEncryptedKey {
     let client_secret = EphemeralSecret::random();
diff --git a/server/crates/arbiter-useragent/Cargo.toml b/server/crates/arbiter-useragent/Cargo.toml
index de46f67..8b6b85b 100644
--- a/server/crates/arbiter-useragent/Cargo.toml
+++ b/server/crates/arbiter-useragent/Cargo.toml
@@ -18,3 +18,4 @@ thiserror.workspace = true
 tokio-stream.workspace = true
 http = "1.4.0"
 rustls-webpki = { version = "0.103.9", features = ["aws-lc-rs"] }
+async-trait.workspace = true
diff --git a/server/crates/arbiter-useragent/tests/auth.rs b/server/crates/arbiter-useragent/tests/auth.rs
index cd9dac1..8d79bbe 100644
--- a/server/crates/arbiter-useragent/tests/auth.rs
+++ b/server/crates/arbiter-useragent/tests/auth.rs
@@ -13,12 +13,14 @@ use ed25519_dalek::SigningKey;
 use kameo::actor::Spawn;
 use tokio::sync::mpsc;
 use tokio::time::{Duration, timeout};
+use async_trait::async_trait;
 
 struct TestTransport {
     inbound_rx: mpsc::Receiver<UserAgentResponse>,
     outbound_tx: mpsc::Sender<UserAgentRequest>,
 }
 
+#[async_trait]
 impl Bi<UserAgentResponse, UserAgentRequest> for TestTransport {
     async fn send(&mut self, item: UserAgentRequest) -> Result<(), arbiter_proto::transport::Error> {
         self.outbound_tx