From 22b987c0324e898c9e97a7da4352df86cf6d8078 Mon Sep 17 00:00:00 2001
From: Marco Castignoli <marco@argot.org>
Date: Thu, 20 Nov 2025 10:15:11 +0100
Subject: [PATCH] Implement retry logic for Etherscan verification submission
 if contract is not yet indexed

---
 .../EtherscanVerifyApiService.ts              | 75 +++++++++++++++----
 .../storage/EtherscanVerifyApiService.spec.ts | 47 ++++++++++++
 2 files changed, 107 insertions(+), 15 deletions(-)

diff --git a/services/server/src/server/services/storageServices/EtherscanVerifyApiService.ts b/services/server/src/server/services/storageServices/EtherscanVerifyApiService.ts
index 804a53104..d1df2d1e1 100644
--- a/services/server/src/server/services/storageServices/EtherscanVerifyApiService.ts
+++ b/services/server/src/server/services/storageServices/EtherscanVerifyApiService.ts
@@ -502,22 +502,37 @@ export class EtherscanVerifyApiService implements WStorageService {
       return;
     }
 
-    let response: EtherscanRpcResponse;
-    try {
-      response = await this.submitVerification(verification, apiBaseUrl);
-    } catch (error: any) {
-      // Store the external verification result if we have job data
-      if (jobData) {
-        this.storeExternalVerificationResult(jobData, {
-          error: error.message,
-        });
-      }
-      logger.error("Failed to submit verification to explorer", {
-        ...submissionContext,
-        error,
+    let response = await this.handleEtherscanApiVerification(
+      verification,
+      apiBaseUrl,
+      submissionContext,
+      jobData,
+    );
+
+    // Case in which Etherscan explorer hasn't indexed the contract yet
+    const maxRetries = 6;
+    const retryDelayMs = 5000;
+    let retries = 0;
+    while (
+      response.message.startsWith("Unable to locate ContractCode at") &&
+      retries < maxRetries
+    ) {
+      retries += 1;
+      logger.info(
+        "Explorer has not indexed contract yet; retrying verification submission",
+        {
+          ...submissionContext,
+          attempt: retries,
+          maxRetries,
+        },
+      );
+      await new Promise((resolve) => setTimeout(resolve, retryDelayMs));
+      response = await this.handleEtherscanApiVerification(
+        verification,
         apiBaseUrl,
-      });
-      throw error;
+        submissionContext,
+        jobData,
+      );
     }
 
     logger.info("Submitted verification to explorer", {
@@ -609,6 +624,36 @@ export class EtherscanVerifyApiService implements WStorageService {
     return (await response.json()) as EtherscanRpcResponse;
   }
 
+  private async handleEtherscanApiVerification(
+    verification: VerificationExport,
+    apiBaseUrl: string,
+    submissionContext: {
+      identifier: string;
+      chainId: number;
+      address: string;
+    },
+    jobData?: {
+      verificationId: string;
+      finishTime: Date;
+    },
+  ): Promise<EtherscanRpcResponse> {
+    try {
+      return await this.submitVerification(verification, apiBaseUrl);
+    } catch (error: any) {
+      if (jobData) {
+        this.storeExternalVerificationResult(jobData, {
+          error: error.message,
+        });
+      }
+      logger.error("Failed to submit verification to explorer", {
+        ...submissionContext,
+        apiBaseUrl,
+        error,
+      });
+      throw error;
+    }
+  }
+
   private async handleBlockscoutVyperVerification(
     verification: VerificationExport,
     apiBaseUrl: string,
diff --git a/services/server/test/unit/storage/EtherscanVerifyApiService.spec.ts b/services/server/test/unit/storage/EtherscanVerifyApiService.spec.ts
index 9b3a0404b..18839883c 100644
--- a/services/server/test/unit/storage/EtherscanVerifyApiService.spec.ts
+++ b/services/server/test/unit/storage/EtherscanVerifyApiService.spec.ts
@@ -325,4 +325,51 @@ describe("EtherscanVerifyApiService", function () {
       },
     );
   });
+
+  it("retries submission when contract is not yet indexed", async () => {
+    const clock = sandbox.useFakeTimers();
+    const baseUrl = "https://etherscan.example/api";
+    const upsertStub = sandbox.stub().resolves();
+    const service = createService(
+      WStorageIdentifiers.EtherscanVerify,
+      baseUrl,
+      upsertStub,
+    );
+    const jobData = {
+      verificationId: "verification-job-id",
+      finishTime: new Date(),
+    };
+
+    const unindexedResponse = mockFetchResponse({
+      status: "0",
+      message: "Unable to locate ContractCode at 0xabc",
+      result: "N/A",
+    });
+    const successResponse = mockFetchResponse({
+      status: "1",
+      message: "OK",
+      result: "receipt-789",
+    });
+
+    fetchStub.onCall(0).resolves(unindexedResponse);
+    fetchStub.onCall(1).resolves(unindexedResponse);
+    fetchStub.onCall(2).resolves(successResponse);
+
+    const verification = structuredClone(MockVerificationExport);
+    const storePromise = service.storeVerification(verification, jobData);
+
+    await clock.tickAsync(10000);
+    await storePromise;
+
+    expect(fetchStub.callCount).to.equal(3);
+    expect(clock.now).to.equal(10000);
+    sinon.assert.calledOnceWithExactly(
+      upsertStub,
+      jobData.verificationId,
+      WStorageIdentifiers.EtherscanVerify,
+      {
+        verificationId: "receipt-789",
+      },
+    );
+  });
 });