diff --git a/packages/core/src/sync/auto-merge.ts b/packages/core/src/sync/auto-merge.ts
index bf492ac03..90fba6351 100644
--- a/packages/core/src/sync/auto-merge.ts
+++ b/packages/core/src/sync/auto-merge.ts
@@ -5,6 +5,7 @@ export const MAX_CREATED_MODELS = 10;
 export const MAX_DELETED_MODELS = 10;
 export const MAX_MODEL_CHURN = 15;
 const REVIEWED_REASONING_PROVIDERS = new Set([
+  "crossmodel",
   "edenai",
   "empiriolabs",
   "hyper",
diff --git a/packages/core/src/sync/providers/crossmodel.ts b/packages/core/src/sync/providers/crossmodel.ts
index beb2b38b8..576cca122 100644
--- a/packages/core/src/sync/providers/crossmodel.ts
+++ b/packages/core/src/sync/providers/crossmodel.ts
@@ -22,11 +22,13 @@ function baseModelExists(modelID: string): boolean {
 // CROSSMODEL_MODELS_URL overrides the endpoint (e.g. a local backend) for testing.
 const API_ENDPOINT = process.env.CROSSMODEL_MODELS_URL ?? "https://www.crossmodel.ai/api/models";
 
+const REASONING_EFFORTS = ["none", "minimal", "low", "medium", "high", "xhigh", "max", "default"] as const;
+
 const ReasoningCapability = z
   .object({
     supported: z.boolean().optional(),
     toggle: z.boolean().nullish().transform((value) => value ?? undefined),
-    effort: z.array(z.string()).nullish().transform((value) => value ?? undefined),
+    effort: z.array(z.enum(REASONING_EFFORTS)).nullish().transform((value) => value ?? undefined),
     budget_tokens: z
       .object({ min: z.number().optional(), max: z.number().optional() })
       .nullish()
@@ -160,15 +162,6 @@ function modalities(values: string[] | undefined, fallback: Modality[]): Modalit
   return [...new Set(result.length > 0 ? result : fallback)];
 }
 
-// models.dev's reasoning_options effort enum (schema.ts ReasoningEffortValue).
-// Guarding against it means an unexpected upstream value is dropped instead of
-// silently producing a TOML that fails `validate`.
-const REASONING_EFFORTS = ["none", "minimal", "low", "medium", "high", "xhigh", "max", "default"] as const;
-type ReasoningEffort = (typeof REASONING_EFFORTS)[number];
-function isReasoningEffort(value: string): value is ReasoningEffort {
-  return (REASONING_EFFORTS as readonly string[]).includes(value);
-}
-
 // Project CrossModel's capabilities.reasoning onto models.dev reasoning_options.
 //   reasoning absent  -> undefined (non-reasoning model; option omitted)
 //   reasoning === {}  -> [] (model reasons, no verified user-selectable control)
@@ -179,8 +172,7 @@ function reasoningOptions(model: CrossModelModel): SyncedModel["reasoning_option
   const options: NonNullable<SyncedModel["reasoning_options"]> = [];
   if (reasoning.toggle === true) options.push({ type: "toggle" });
   if (reasoning.effort !== undefined) {
-    const values = reasoning.effort.filter(isReasoningEffort);
-    if (values.length > 0) options.push({ type: "effort", values });
+    if (reasoning.effort.length > 0) options.push({ type: "effort", values: reasoning.effort });
   }
   if (reasoning.budget_tokens !== undefined) {
     const budget: { type: "budget_tokens"; min?: number; max?: number } = { type: "budget_tokens" };
diff --git a/packages/core/test/auto-merge.test.ts b/packages/core/test/auto-merge.test.ts
index 1d3d0117b..04c3ad9a9 100644
--- a/packages/core/test/auto-merge.test.ts
+++ b/packages/core/test/auto-merge.test.ts
@@ -82,7 +82,7 @@ test("does not inspect deleted models", async () => {
 });
 
 test("allows reviewed providers with explicit reasoning options", async () => {
-  for (const provider of ["edenai", "empiriolabs", "hyper", "kilo", "llmgateway", "merge-gateway", "nano-gpt", "openrouter", "venice"]) {
+  for (const provider of ["crossmodel", "edenai", "empiriolabs", "hyper", "kilo", "llmgateway", "merge-gateway", "nano-gpt", "openrouter", "venice"]) {
     const decision = await classifyAutoMerge(
       [{ status: "updated", path: `providers/${provider}/models/reasoner.toml` }],
       async () => fullModel(true, 'reasoning_options = [{ type = "toggle" }]'),
diff --git a/packages/core/test/sync.test.ts b/packages/core/test/sync.test.ts
index c3094d00a..1bc6e055c 100644
--- a/packages/core/test/sync.test.ts
+++ b/packages/core/test/sync.test.ts
@@ -467,6 +467,46 @@ test("parses CrossModel's nullable reasoning controls", () => {
   });
 });
 
+test("syncs CrossModel's explicit reasoning controls", () => {
+  const model = buildCrossModel(
+    crossModelModel({
+      capabilities: {
+        json: true,
+        reasoning: {
+          supported: true,
+          toggle: true,
+          effort: ["low", "high", "max"],
+          budget_tokens: { min: 1_024, max: 32_000 },
+        },
+      },
+    }),
+    undefined,
+  );
+
+  expect(model).toMatchObject({
+    reasoning_options: [
+      { type: "toggle" },
+      { type: "effort", values: ["low", "high", "max"] },
+      { type: "budget_tokens", min: 1_024, max: 32_000 },
+    ],
+  });
+});
+
+test("rejects unknown CrossModel reasoning efforts", () => {
+  expect(() =>
+    CrossModelResponse.parse({
+      data: [
+        {
+          ...crossModelModel(),
+          capabilities: {
+            reasoning: { supported: true, effort: ["unexpected"] },
+          },
+        },
+      ],
+    })
+  ).toThrow();
+});
+
 test("syncs NanoGPT's verified reasoning, pricing, limits, and open-weight metadata", () => {
   const model = buildNanoGptModel(nanoGptModel({
     pricing: {