diff --git a/packages/client-runtime/src/state/threadExecution.test.ts b/packages/client-runtime/src/state/threadExecution.test.ts
index fd03b06b32017..c02e2c13fefbe 100644
--- a/packages/client-runtime/src/state/threadExecution.test.ts
+++ b/packages/client-runtime/src/state/threadExecution.test.ts
@@ -24,10 +24,10 @@ import {
   deriveLatestThreadRun,
   deriveProviderSubagentStatus,
   deriveResumableRunId,
+  formatModelSelectionEffort,
   deriveRunlessWorkStartedAt,
   deriveThreadActivityRun,
   deriveThreadRuntime,
-  formatModelSelectionEffort,
   isBackgroundWorkStopPending,
   presentPendingBackgroundWork,
   presentProviderGoal,
@@ -476,6 +476,38 @@ describe("provider-reported model selection", () => {
 });
 
 describe("formatModelSelectionEffort", () => {
+  it("finds the catalog model when the selection names it by display name or alias", () => {
+    const selection = {
+      ...v2Projection.thread.modelSelection,
+      model: "GPT-6 Luna",
+      options: [{ id: "reasoning_effort", value: "medium" }],
+    };
+    const models = [
+      {
+        slug: "custom:GPT-6 Luna-12",
+        name: "GPT-6 Luna",
+        aliases: ["Luna-12"],
+        isCustom: true,
+        capabilities: {
+          optionDescriptors: [
+            {
+              id: "reasoning_effort",
+              label: "Reasoning",
+              type: "select" as const,
+              options: [
+                { id: "medium", label: "Medium" },
+                { id: "high", label: "High" },
+              ],
+            },
+          ],
+        },
+      },
+    ];
+
+    expect(formatModelSelectionEffort(selection, models)).toBe("Medium");
+    expect(formatModelSelectionEffort({ ...selection, model: "Luna-12" }, models)).toBe("Medium");
+  });
+
   it("labels an old Ultracode effort by the effort it runs at", () => {
     const models = [
       {
diff --git a/packages/client-runtime/src/state/threadExecution.ts b/packages/client-runtime/src/state/threadExecution.ts
index 6b260d7224c20..2787122fba139 100644
--- a/packages/client-runtime/src/state/threadExecution.ts
+++ b/packages/client-runtime/src/state/threadExecution.ts
@@ -166,12 +166,27 @@ export const REASONING_EFFORT_OPTION_IDS: ReadonlyArray<string> = [
   "thinking_level",
 ];
 
+function findSelectionCatalogModel(
+  models: ReadonlyArray<ServerProviderModel>,
+  model: string,
+): ServerProviderModel | undefined {
+  const name = model.trim().toLowerCase();
+  return (
+    models.find((candidate) => candidate.slug === model) ??
+    models.find(
+      (candidate) =>
+        candidate.name.trim().toLowerCase() === name ||
+        candidate.aliases?.some((alias) => alias.trim().toLowerCase() === name),
+    )
+  );
+}
+
 export function formatModelSelectionEffort(
   selection: ModelSelection,
   models: ReadonlyArray<ServerProviderModel> = [],
   reportedSelection?: ModelSelection | null,
 ): string | null {
-  const caps = models.find((model) => model.slug === selection.model)?.capabilities;
+  const caps = findSelectionCatalogModel(models, selection.model)?.capabilities;
   if (!caps) return null;
   const options = withLegacyUltracodeEffort(caps.optionDescriptors, selection.options);
   const current = options ? { ...selection, options } : selection;