diff --git a/packages/kilo-gateway/src/api/models.ts b/packages/kilo-gateway/src/api/models.ts
index b5bb9ee2467..5e62fedd644 100644
--- a/packages/kilo-gateway/src/api/models.ts
+++ b/packages/kilo-gateway/src/api/models.ts
@@ -30,6 +30,7 @@ const openRouterModelSchema = z.object({
   top_provider: z.object({ max_completion_tokens: z.number().nullish() }).optional(),
   supported_parameters: z.array(z.string()).optional(),
   preferredIndex: z.number().optional(),
+  isFree: z.boolean().optional(),
   opencode: z
     .object({
       family: z.string().optional(),
@@ -162,6 +163,7 @@ function transformToModelDevFormat(model: OpenRouterModel): any {
     variants: model.opencode?.variants,
     prompt: model.opencode?.prompt,
     tool_call: supportsTools,
+    isFree: model.isFree,
     ...(inputPrice !== undefined &&
       outputPrice !== undefined && {
         cost: {
diff --git a/packages/kilo-vscode/webview-ui/src/components/shared/model-selector-utils.ts b/packages/kilo-vscode/webview-ui/src/components/shared/model-selector-utils.ts
index 2c65493465e..c32309e2375 100644
--- a/packages/kilo-vscode/webview-ui/src/components/shared/model-selector-utils.ts
+++ b/packages/kilo-vscode/webview-ui/src/components/shared/model-selector-utils.ts
@@ -10,12 +10,8 @@ export function providerSortKey(providerID: string, order = PROVIDER_ORDER): num
   return idx >= 0 ? idx : order.length
 }
 
-export function isFree(model: Pick<EnrichedModel, "isFree" | "cost" | "providerID">): boolean {
-  if (model.isFree !== undefined) return model.isFree
-  // TODO: temporary — this logic will be moved to the backend
-  if (model.providerID !== KILO_GATEWAY_ID) return false
-  // TODO: fallback to cost check — delete once backend ships isFree attribute
-  return model.cost?.input === 0 && model.cost?.output === 0
+export function isFree(model: Pick<EnrichedModel, "isFree">): boolean {
+  return model.isFree === true
 }
 
 export function stripSubProviderPrefix(name: string): string {
diff --git a/packages/opencode/src/provider/models.ts b/packages/opencode/src/provider/models.ts
index 5d61672458a..2751547c675 100644
--- a/packages/opencode/src/provider/models.ts
+++ b/packages/opencode/src/provider/models.ts
@@ -86,6 +86,7 @@ export namespace ModelsDev {
     // kilocode_change start
     recommendedIndex: z.number().optional(),
     prompt: Prompt.optional().catch(undefined),
+    isFree: z.boolean().optional(),
     // kilocode_change end
 
     experimental: z.boolean().optional(),
diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index eef41c93ce9..e0e4b6142db 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -689,6 +689,7 @@ export namespace Provider {
       // kilocode_change start
       recommendedIndex: z.number().optional(),
       prompt: Prompt.optional().catch(undefined),
+      isFree: z.boolean().optional(),
       // kilocode_change end
     })
     .meta({
@@ -775,6 +776,7 @@ export namespace Provider {
       variants: provider.id === "kilo" ? (model.variants ?? {}) : {},
       recommendedIndex: model.recommendedIndex,
       prompt: model.prompt,
+      isFree: model.isFree,
       // kilocode_change end
     }
 
@@ -923,6 +925,7 @@ export namespace Provider {
           // kilocode_change start
           recommendedIndex: model.recommendedIndex ?? existingModel?.recommendedIndex,
           prompt: model.prompt ?? existingModel?.prompt,
+          isFree: model.isFree ?? existingModel?.isFree,
           // kilocode_change end
         }
         const merged = mergeDeep(ProviderTransform.variants(parsedModel), model.variants ?? {})
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index 8c6a10a5427..bce8bbdea7b 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -1214,6 +1214,7 @@ export type ProviderConfig = {
       }
       recommendedIndex?: number
       prompt?: "codex" | "gemini" | "beast" | "anthropic" | "trinity" | "anthropic_without_todo"
+      isFree?: boolean
       experimental?: boolean
       status?: "alpha" | "beta" | "deprecated"
       options?: {
@@ -1646,6 +1647,7 @@ export type Model = {
   }
   recommendedIndex?: number
   prompt?: "codex" | "gemini" | "beast" | "anthropic" | "trinity" | "anthropic_without_todo"
+  isFree?: boolean
 }
 
 export type Provider = {
@@ -4159,6 +4161,7 @@ export type ProviderListResponses = {
           }
           recommendedIndex?: number
           prompt?: "codex" | "gemini" | "beast" | "anthropic" | "trinity" | "anthropic_without_todo"
+          isFree?: boolean
           experimental?: boolean
           status?: "alpha" | "beta" | "deprecated"
           options: {
diff --git a/packages/sdk/openapi.json b/packages/sdk/openapi.json
index c65a4ad275e..5181da5b925 100644
--- a/packages/sdk/openapi.json
+++ b/packages/sdk/openapi.json
@@ -4838,6 +4838,9 @@
                                   "type": "string",
                                   "enum": ["codex", "gemini", "beast", "anthropic", "trinity", "anthropic_without_todo"]
                                 },
+                                "isFree": {
+                                  "type": "boolean"
+                                },
                                 "experimental": {
                                   "type": "boolean"
                                 },
@@ -11403,6 +11406,9 @@
                   "type": "string",
                   "enum": ["codex", "gemini", "beast", "anthropic", "trinity", "anthropic_without_todo"]
                 },
+                "isFree": {
+                  "type": "boolean"
+                },
                 "experimental": {
                   "type": "boolean"
                 },
@@ -12373,6 +12379,9 @@
           "prompt": {
             "type": "string",
             "enum": ["codex", "gemini", "beast", "anthropic", "trinity", "anthropic_without_todo"]
+          },
+          "isFree": {
+            "type": "boolean"
           }
         },
         "required": [