diff --git a/changes.proto b/changes.proto
index e0ad0df..ed25ff7 100644
--- a/changes.proto
+++ b/changes.proto
@@ -7,6 +7,7 @@ import "google/protobuf/timestamp.proto";
 import "bookmarks.proto";
 import "items.proto";
 import "snapshots.proto";
+import "account.proto";
 
 //              ______
 //           ,'"       "-._
@@ -231,6 +232,9 @@ message UpdatePlannedChangesRequest {
 
   // the changing items
   repeated MappedItemDiff changingItems = 2;
+
+  // Overrides the stored blast radius config for this change
+  optional account.BlastRadiusConfig blastRadiusConfigOverride = 3;
 }
 
 message ListAppChangesSummaryRequest {
diff --git a/config.proto b/config.proto
index 8559362..1bd4da1 100644
--- a/config.proto
+++ b/config.proto
@@ -5,8 +5,15 @@ option go_package = "github.com/overmindtech/sdp-go;sdp";
 
 // a simple key-value store to store the config for the CLI
 service ConfigService {
+    // GetConfig provides raw access to the underlying stored data. [experimental]
     rpc GetConfig(GetConfigRequest) returns (GetConfigResponse) {}
+    // SetConfig provides raw access to the underlying stored data. [experimental]
     rpc SetConfig(SetConfigRequest) returns (SetConfigResponse) {}
+
+    // Get the account config for the user's account
+    rpc GetAccountConfig(GetAccountConfigRequest) returns (GetAccountConfigResponse);
+    // Update the account config for the user's account
+    rpc UpdateAccountConfig(UpdateAccountConfigRequest) returns (UpdateAccountConfigResponse);
 }
 
 message GetConfigRequest {
@@ -22,3 +29,37 @@ message SetConfigRequest {
 }
 message SetConfigResponse {
 }
+
+
+// The config that is used when calculating the blast radius for a change, this
+// does not affect manually requested blast radii vie the "Explore" view or the
+// API
+message BlastRadiusConfig {
+    // The maximum number of items that can be returned in a single blast radius
+    // request. Once a request has hit this limit, all currently running
+    // requests will be cancelled and the blast radius returned as-is
+    int32 maxItems = 1;
+
+    // How deeply to link when calculating the blast radius for a change
+    int32 linkDepth = 2;
+}
+
+message AccountConfig {
+    // The blast radius config for this account
+    BlastRadiusConfig blastRadius = 1;
+}
+
+message GetAccountConfigRequest {}
+
+message GetAccountConfigResponse {
+    AccountConfig config = 1;
+}
+
+// Updates the account config for the user's account.
+message UpdateAccountConfigRequest {
+    AccountConfig config = 1;
+}
+
+message UpdateAccountConfigResponse {
+    AccountConfig config = 1;
+}