diff --git a/server/crates/arbiter-server/src/actors/flow_coordinator/mod.rs b/server/crates/arbiter-server/src/actors/flow_coordinator/mod.rs
index fba78c8..c9f8f5b 100644
--- a/server/crates/arbiter-server/src/actors/flow_coordinator/mod.rs
+++ b/server/crates/arbiter-server/src/actors/flow_coordinator/mod.rs
@@ -94,6 +94,13 @@ impl FlowCoordinator {
         self.client_ids.contains_key(&client_id)
     }
 
+    /// Returns the DB client_ids of all currently connected SDK clients.
+    /// Used by operator sessions on startup to seed their approved-client set.
+    #[message]
+    pub fn get_connected_client_ids(&self) -> Vec<i32> {
+        self.client_ids.keys().copied().collect()
+    }
+
     #[message(ctx)]
     pub async fn request_client_approval(
         &mut self,
diff --git a/server/crates/arbiter-server/src/peers/operator/session/handlers.rs b/server/crates/arbiter-server/src/peers/operator/session/handlers.rs
index 9565146..4bad681 100644
--- a/server/crates/arbiter-server/src/peers/operator/session/handlers.rs
+++ b/server/crates/arbiter-server/src/peers/operator/session/handlers.rs
@@ -6,7 +6,10 @@ use crate::{
     },
     actors::flow_coordinator::{IsClientConnected, client_connect_approval::ClientApprovalAnswer},
     actors::vault::VaultState,
-    db::models::{EvmWalletAccess, NewEvmWalletAccess, ProgramClient, ProgramClientMetadata},
+    db::{
+        models::{EvmWalletAccess, NewEvmWalletAccess, ProgramClient, ProgramClientMetadata},
+        schema::program_client,
+    },
     evm::policies::{Grant, SpecificGrant},
 };
 use arbiter_crypto::authn;
@@ -144,6 +147,14 @@ impl OperatorSession {
         wallet_address: Address,
         transaction: TxEip1559,
     ) -> Result<Signature, SignTransactionError> {
+        if !self.approved_client_ids.contains(&client_id) {
+            warn!(
+                client_id,
+                "operator attempted to sign for client not in its approved set"
+            );
+            return Err(SignTransactionError::ClientNotConnected);
+        }
+
         let connected = self
             .props
             .actors
@@ -153,6 +164,7 @@ impl OperatorSession {
             .unwrap_or(false);
 
         if !connected {
+            self.approved_client_ids.remove(&client_id);
             warn!(client_id, "operator attempted to sign for disconnected client");
             return Err(SignTransactionError::ClientNotConnected);
         }
@@ -267,6 +279,30 @@ impl OperatorSession {
 
         ctx.actor_ref().unlink(&pending_approval.controller).await;
 
+        if approved {
+            let pubkey_bytes = pending_approval.pubkey.to_bytes();
+            match self.props.db.get().await {
+                Ok(mut conn) => {
+                    match program_client::table
+                        .filter(program_client::public_key.eq(pubkey_bytes.as_slice()))
+                        .select(program_client::id)
+                        .first::<i32>(&mut conn)
+                        .await
+                    {
+                        Ok(client_id) => {
+                            self.approved_client_ids.insert(client_id);
+                        }
+                        Err(err) => {
+                            error!(?err, "Failed to look up client_id for approved pubkey");
+                        }
+                    }
+                }
+                Err(err) => {
+                    error!(?err, "DB pool error after client approval");
+                }
+            }
+        }
+
         Ok(())
     }
 
diff --git a/server/crates/arbiter-server/src/peers/operator/session/mod.rs b/server/crates/arbiter-server/src/peers/operator/session/mod.rs
index 0fe2c84..eab628a 100644
--- a/server/crates/arbiter-server/src/peers/operator/session/mod.rs
+++ b/server/crates/arbiter-server/src/peers/operator/session/mod.rs
@@ -1,7 +1,7 @@
 use super::{OutOfBand, OperatorConnection};
 use crate::{
     actors::{
-        flow_coordinator::client_connect_approval::ClientApprovalController,
+        flow_coordinator::{GetConnectedClientIds, client_connect_approval::ClientApprovalController},
         operator_registry::ConnectOperator,
     },
     peers::client::ClientProfile,
@@ -10,7 +10,7 @@ use arbiter_crypto::authn;
 use arbiter_proto::transport::Sender;
 
 use kameo::{Actor, actor::ActorRef, messages};
-use std::{borrow::Cow, collections::HashMap};
+use std::{borrow::Cow, collections::{HashMap, HashSet}};
 use thiserror::Error;
 use tracing::error;
 
@@ -54,6 +54,10 @@ pub struct OperatorSession {
     sender: Box<dyn Sender<OutOfBand>>,
 
     pending_client_approvals: HashMap<Vec<u8>, PendingClientApproval>,
+    /// DB client_ids this operator session is allowed to sign for.
+    /// Seeded from currently-connected clients on start, then updated as
+    /// approvals are granted or denied during the session lifetime.
+    approved_client_ids: HashSet<i32>,
 }
 
 pub mod handlers;
@@ -64,6 +68,7 @@ impl OperatorSession {
             props,
             sender,
             pending_client_approvals: HashMap::default(),
+            approved_client_ids: HashSet::default(),
         }
     }
 }
@@ -106,7 +111,7 @@ impl Actor for OperatorSession {
 
     type Error = Error;
 
-    async fn on_start(args: Self::Args, this: ActorRef<Self>) -> Result<Self, Self::Error> {
+    async fn on_start(mut args: Self::Args, this: ActorRef<Self>) -> Result<Self, Self::Error> {
         args.props
             .actors
             .operator_registry
@@ -121,6 +126,16 @@ impl Actor for OperatorSession {
                 );
                 Error::internal("Failed to register operator connection with operator registry")
             })?;
+
+        // Seed approved set with clients already connected when this session starts.
+        // New clients will be added via handle_new_client_approve as they are approved.
+        match args.props.actors.flow_coordinator.ask(GetConnectedClientIds {}).await {
+            Ok(ids) => args.approved_client_ids.extend(ids),
+            Err(err) => {
+                error!(?err, "Failed to fetch connected client IDs on operator session start");
+            }
+        }
+
         Ok(args)
     }