diff --git a/packages/opencode/src/provider/models.ts b/packages/opencode/src/provider/models.ts
index cedeed69a2..7a34af4f4a 100644
--- a/packages/opencode/src/provider/models.ts
+++ b/packages/opencode/src/provider/models.ts
@@ -18,20 +18,22 @@ export namespace ModelsDev {
     reasoning: z.boolean(),
     temperature: z.boolean(),
     tool_call: z.boolean(),
-    cost: z.object({
-      input: z.number(),
-      output: z.number(),
-      cache_read: z.number().optional(),
-      cache_write: z.number().optional(),
-      context_over_200k: z
-        .object({
-          input: z.number(),
-          output: z.number(),
-          cache_read: z.number().optional(),
-          cache_write: z.number().optional(),
-        })
-        .optional(),
-    }),
+    cost: z
+      .object({
+        input: z.number(),
+        output: z.number(),
+        cache_read: z.number().optional(),
+        cache_write: z.number().optional(),
+        context_over_200k: z
+          .object({
+            input: z.number(),
+            output: z.number(),
+            cache_read: z.number().optional(),
+            cache_write: z.number().optional(),
+          })
+          .optional(),
+      })
+      .optional(),
     limit: z.object({
       context: z.number(),
       output: z.number(),
diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index 3a29655a02..c83b3ac714 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -388,13 +388,13 @@ export namespace Provider {
       headers: model.headers ?? {},
       options: model.options ?? {},
       cost: {
-        input: model.cost.input,
-        output: model.cost.output,
+        input: model.cost?.input ?? 0,
+        output: model.cost?.output ?? 0,
         cache: {
-          read: model.cost.cache_read ?? 0,
-          write: model.cost.cache_write ?? 0,
+          read: model.cost?.cache_read ?? 0,
+          write: model.cost?.cache_write ?? 0,
         },
-        experimentalOver200K: model.cost.context_over_200k
+        experimentalOver200K: model.cost?.context_over_200k
           ? {
               cache: {
                 read: model.cost.context_over_200k.cache_read ?? 0,