diff --git a/packages/opencode/src/global/index.ts b/packages/opencode/src/global/index.ts
index 869019e2ce74..6669bdae0949 100644
--- a/packages/opencode/src/global/index.ts
+++ b/packages/opencode/src/global/index.ts
@@ -49,6 +49,9 @@ if (version !== CACHE_VERSION) {
         }),
       ),
     )
-  } catch (e) {}
+  } catch (e) {
+    // Log cache cleanup failure but continue - non-critical operation
+    console.warn("Failed to clean cache directory:", e)
+  }
   await Filesystem.write(path.join(Global.Path.cache, "version"), CACHE_VERSION)
 }
diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index c6784f450244..cd57b228fc1e 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -1372,7 +1372,14 @@ export namespace Provider {
 
           const mod = await import(installedPath)
 
-          const fn = mod[Object.keys(mod).find((key) => key.startsWith("create"))!]
+          const createKey = Object.keys(mod).find((key) => key.startsWith("create"))
+          if (!createKey) {
+            throw new InitError(
+              { providerID: model.providerID },
+              { cause: new Error(`No create function found in module ${installedPath}`) },
+            )
+          }
+          const fn = mod[createKey]
           const loaded = fn({
             name: model.providerID,
             ...options,
diff --git a/packages/opencode/src/util/rpc.ts b/packages/opencode/src/util/rpc.ts
index ebd8be40e455..212f07e87abd 100644
--- a/packages/opencode/src/util/rpc.ts
+++ b/packages/opencode/src/util/rpc.ts
@@ -5,10 +5,31 @@ export namespace Rpc {
 
   export function listen(rpc: Definition) {
     onmessage = async (evt) => {
-      const parsed = JSON.parse(evt.data)
-      if (parsed.type === "rpc.request") {
-        const result = await rpc[parsed.method](parsed.input)
-        postMessage(JSON.stringify({ type: "rpc.result", result, id: parsed.id }))
+      try {
+        const parsed = JSON.parse(evt.data)
+        if (parsed.type === "rpc.request") {
+          const method = rpc[parsed.method]
+          if (!method) {
+            postMessage(
+              JSON.stringify({
+                type: "rpc.error",
+                id: parsed.id,
+                error: `Unknown method: ${parsed.method}`,
+              }),
+            )
+            return
+          }
+          const result = await method(parsed.input)
+          postMessage(JSON.stringify({ type: "rpc.result", result, id: parsed.id }))
+        }
+      } catch (e) {
+        // Send error response for JSON parse errors or method execution failures
+        postMessage(
+          JSON.stringify({
+            type: "rpc.error",
+            error: e instanceof Error ? e.message : String(e),
+          }),
+        )
       }
     }
   }