diff --git a/src/config/index.ts b/src/config/index.ts
index 1e10db8..30b8bce 100644
--- a/src/config/index.ts
+++ b/src/config/index.ts
@@ -21,6 +21,21 @@ export function loadConfig(override = true): void {
 
 loadConfig(false);
 
+export const RPC_429_USER_MESSAGE =
+  "Your RPC endpoint is returning too many requests (HTTP 429). Please configure your own private RPC URL via RPC_URL and try again.";
+
+/**
+ * Returns true when Satellite is using the default (public) RPC URL,
+ * i.e. when the user has NOT provided a custom RPC_URL override.
+ */
+export function isUsingPublicRpc(): boolean {
+  return !process.env.RPC_URL || process.env.RPC_URL.trim().length === 0;
+}
+
+export function isRpc429Error(err: unknown): boolean {
+  return (err as any)?.response?.status === 429;
+}
+
 export function getRuntimeConfig() {
   return {
     get API_KEY() {
diff --git a/src/domain/portal/publish.ts b/src/domain/portal/publish.ts
index 4ef9bca..b1a3ede 100644
--- a/src/domain/portal/publish.ts
+++ b/src/domain/portal/publish.ts
@@ -9,7 +9,7 @@ import { generateKeyPairFromSeed } from "@stablelib/ed25519";
 import * as ucans from "@ucans/ucans";
 import { AgentClient } from "../../sdk/smart-agent";
 import { FileManager } from "../../sdk/file-manager";
-import { getRuntimeConfig } from "../../config";
+import { getRuntimeConfig, isUsingPublicRpc, isRpc429Error, RPC_429_USER_MESSAGE } from "../../config";
 
 import type { PublishResult } from "../../types";
 
@@ -104,6 +104,12 @@ export const handleExistingFileOp = async (fileId: string, operation: "update" |
 
     return executeOperation(fileManager, file, operation);
   } catch (error: any) {
+    if (isUsingPublicRpc() && isRpc429Error(error)) {
+      // For public RPCs, map HTTP 429 into a clear user-facing message.
+      logger.error(`Failed to publish file ${fileId}: ${RPC_429_USER_MESSAGE}`);
+      throw new Error(RPC_429_USER_MESSAGE);
+    }
+
     logger.error(`Failed to publish file ${fileId}:`, error);
     throw error;
   }
diff --git a/src/infra/worker/eventProcessor.ts b/src/infra/worker/eventProcessor.ts
index 65b6c12..5bee74f 100644
--- a/src/infra/worker/eventProcessor.ts
+++ b/src/infra/worker/eventProcessor.ts
@@ -1,4 +1,4 @@
-import { getRuntimeConfig } from "../../config";
+import { getRuntimeConfig, isUsingPublicRpc, isRpc429Error, RPC_429_USER_MESSAGE } from "../../config";
 import { handleNewFileOp, getProxyAuthParams, handleExistingFileOp } from "../../domain/portal";
 import { FilesModel, EventsModel } from "../database/models";
 import type { Event, ProcessResult, UpdateFilePayload } from "../../types";
@@ -31,8 +31,11 @@ export const processEvent = async (event: Event): Promise<ProcessResult> => {
   } catch (error) {
     const normalized = normalizeRateLimitError(error);
     if (normalized instanceof RateLimitError) throw normalized;
-    const errorMsg = error instanceof Error ? error.message : String(error);
-    logger.error(`Error processing ${type} event for file ${fileId}:`, errorMsg);
+    let errorMsg = error instanceof Error ? error.message : String(error);
+    if (isUsingPublicRpc() && isRpc429Error(error)) {
+      errorMsg = RPC_429_USER_MESSAGE;
+    }
+    logger.error(`Error processing ${type} event for file ${fileId}: ${errorMsg}`);
     return { success: false, error: errorMsg };
   }
 };
diff --git a/src/sdk/smart-agent.ts b/src/sdk/smart-agent.ts
index e13d2b9..f58824a 100644
--- a/src/sdk/smart-agent.ts
+++ b/src/sdk/smart-agent.ts
@@ -81,19 +81,15 @@ export class AgentClient {
     request: IExecuteUserOperationRequest | IExecuteUserOperationRequest[],
     customGasLimit?: number,
   ) {
-    try {
-      const smartAccountAgent = this.getSmartAccountAgent();
-
-      const callData = await this.getCallData(request);
-
-      return await smartAccountAgent.sendUserOperation({
-        callData,
-        callGasLimit: BigInt(customGasLimit || this.MAX_CALL_GAS_LIMIT),
-        nonce: getNonce(),
-      });
-    } catch (error) {
-      throw error;
-    }
+    const smartAccountAgent = this.getSmartAccountAgent();
+
+    const callData = await this.getCallData(request);
+
+    return await smartAccountAgent.sendUserOperation({
+      callData,
+      callGasLimit: BigInt(customGasLimit || this.MAX_CALL_GAS_LIMIT),
+      nonce: getNonce(),
+    });
   }
 
   async executeUserOperationRequest(