diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index 088aa2fd7664..566e906c516f 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -1394,13 +1394,20 @@ export const layer = Layer.effect(
         // extend database from config
         for (const [providerID, provider] of configProviders) {
           const existing = database[providerID]
+          const providerNpm = provider.npm
+          const existingModels = existing?.models ?? {}
           const parsed: Info = {
             id: ProviderV2.ID.make(providerID),
             name: provider.name ?? existing?.name ?? providerID,
             env: provider.env ?? existing?.env ?? [],
             options: mergeDeep(existing?.options ?? {}, provider.options ?? {}),
             source: "config",
-            models: existing?.models ?? {},
+            models: providerNpm
+              ? mapValues(existingModels, (model) => ({
+                  ...model,
+                  api: { ...model.api, npm: providerNpm },
+                }))
+              : existingModels,
           }
 
           for (const [modelID, model] of Object.entries(provider.models ?? {})) {
diff --git a/packages/opencode/test/provider/provider.test.ts b/packages/opencode/test/provider/provider.test.ts
index 05d22aec4142..7259c685ece9 100644
--- a/packages/opencode/test/provider/provider.test.ts
+++ b/packages/opencode/test/provider/provider.test.ts
@@ -123,6 +123,25 @@ it.instance(
   { config: { provider: { anthropic: { options: { apiKey: "config-api-key" } } } } },
 )
 
+it.instance(
+  "provider-level npm applies to existing models without model overrides",
+  Effect.gen(function* () {
+    const providers = yield* list
+    const model = providers[ProviderV2.ID.anthropic].models["claude-sonnet-4-20250514"]
+    expect(model.api.npm).toBe("@ai-sdk/openai-compatible")
+  }),
+  {
+    config: {
+      provider: {
+        anthropic: {
+          npm: "@ai-sdk/openai-compatible",
+          options: { apiKey: "config-api-key" },
+        },
+      },
+    },
+  },
+)
+
 it.instance(
   "disabled_providers excludes provider",
   Effect.gen(function* () {