From bc9454db5e0258eaa964f36c37d7204244ece9a5 Mon Sep 17 00:00:00 2001
From: Tanya S <120410716+stubbsta@users.noreply.github.com>
Date: Thu, 12 Mar 2026 22:27:50 +0200
Subject: [PATCH] Chore: Simplify on chain group manager error handling (#3678)

---
 tests/node/test_wakunode_legacy_lightpush.nim |   7 +-
 tests/node/test_wakunode_lightpush.nim        |   7 +-
 .../test_rln_group_manager_onchain.nim        |  99 ++---
 tests/waku_rln_relay/test_waku_rln_relay.nim  |  26 +-
 .../test_wakunode_rln_relay.nim               |  49 +--
 tests/wakunode_rest/test_rest_relay.nim       |  39 +-
 .../rln_keystore_generator.nim                |   4 +-
 .../group_manager/group_manager_base.nim      |   4 +-
 .../group_manager/on_chain/group_manager.nim  | 358 +++++++++---------
 .../group_manager/on_chain/retry_wrapper.nim  |  41 +-
 waku/waku_rln_relay/rln_relay.nim             |   4 +-
 11 files changed, 288 insertions(+), 350 deletions(-)

diff --git a/tests/node/test_wakunode_legacy_lightpush.nim b/tests/node/test_wakunode_legacy_lightpush.nim
index 902464bcd..68c6cacde 100644
--- a/tests/node/test_wakunode_legacy_lightpush.nim
+++ b/tests/node/test_wakunode_legacy_lightpush.nim
@@ -134,11 +134,8 @@ suite "RLN Proofs as a Lightpush Service":
     let manager1 = cast[OnchainGroupManager](server.wakuRlnRelay.groupManager)
     let idCredentials1 = generateCredentials()
 
-    try:
-      waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     let rootUpdated1 = waitFor manager1.updateRoots()
     info "Updated root for node1", rootUpdated1
diff --git a/tests/node/test_wakunode_lightpush.nim b/tests/node/test_wakunode_lightpush.nim
index 66b87b85e..b407327e3 100644
--- a/tests/node/test_wakunode_lightpush.nim
+++ b/tests/node/test_wakunode_lightpush.nim
@@ -137,11 +137,8 @@ suite "RLN Proofs as a Lightpush Service":
     let manager1 = cast[OnchainGroupManager](server.wakuRlnRelay.groupManager)
     let idCredentials1 = generateCredentials()
 
-    try:
-      waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     let rootUpdated1 = waitFor manager1.updateRoots()
     info "Updated root for node1", rootUpdated1
diff --git a/tests/waku_rln_relay/test_rln_group_manager_onchain.nim b/tests/waku_rln_relay/test_rln_group_manager_onchain.nim
index aac900911..29da94129 100644
--- a/tests/waku_rln_relay/test_rln_group_manager_onchain.nim
+++ b/tests/waku_rln_relay/test_rln_group_manager_onchain.nim
@@ -74,10 +74,11 @@ suite "Onchain group manager":
       raiseAssert "Expected error when keystore file doesn't exist"
 
   test "trackRootChanges: should guard against uninitialized state":
-    try:
-      discard manager.trackRootChanges()
-    except CatchableError:
-      check getCurrentExceptionMsg().len == 38
+    let initializedResult = waitFor manager.trackRootChanges()
+
+    check:
+      initializedResult.isErr()
+      initializedResult.error == "OnchainGroupManager is not initialized"
 
   test "trackRootChanges: should sync to the state of the group":
     let credentials = generateCredentials()
@@ -86,10 +87,8 @@ suite "Onchain group manager":
 
     let merkleRootBefore = waitFor manager.fetchMerkleRoot()
 
-    try:
-      waitFor manager.register(credentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    (waitFor manager.register(credentials, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     discard waitFor withTimeout(trackRootChanges(manager), 15.seconds)
 
@@ -110,13 +109,11 @@ suite "Onchain group manager":
 
     let merkleRootBefore = waitFor manager.fetchMerkleRoot()
 
-    try:
-      for i in 0 ..< credentials.len():
-        info "Registering credential", index = i, credential = credentials[i]
-        waitFor manager.register(credentials[i], UserMessageLimit(20))
-        discard waitFor manager.updateRoots()
-    except Exception, CatchableError:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    for i in 0 ..< credentials.len():
+      info "Registering credential", index = i, credential = credentials[i]
+      (waitFor manager.register(credentials[i], UserMessageLimit(20))).isOkOr:
+        assert false, "Failed to register credential " & $i & ": " & error
+      discard waitFor manager.updateRoots()
 
     let merkleRootAfter = waitFor manager.fetchMerkleRoot()
 
@@ -127,16 +124,15 @@ suite "Onchain group manager":
   test "register: should guard against uninitialized state":
     let dummyCommitment = default(IDCommitment)
 
-    try:
-      waitFor manager.register(
-        RateCommitment(
-          idCommitment: dummyCommitment, userMessageLimit: UserMessageLimit(20)
-        )
+    let res = waitFor manager.register(
+      RateCommitment(
+        idCommitment: dummyCommitment, userMessageLimit: UserMessageLimit(20)
       )
-    except CatchableError:
-      assert true
-    except Exception:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    )
+
+    check:
+      res.isErr()
+      res.error == "OnchainGroupManager is not initialized"
 
   test "register: should register successfully":
     # TODO :- similar to ```trackRootChanges: should fetch history correctly```
@@ -146,11 +142,8 @@ suite "Onchain group manager":
     let idCredentials = generateCredentials()
     let merkleRootBefore = waitFor manager.fetchMerkleRoot()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     let merkleRootAfter = waitFor manager.fetchMerkleRoot()
 
@@ -177,26 +170,25 @@ suite "Onchain group manager":
 
     manager.onRegister(callback)
 
-    try:
+    (
       waitFor manager.register(
         RateCommitment(
           idCommitment: idCommitment, userMessageLimit: UserMessageLimit(20)
         )
       )
-    except Exception, CatchableError:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    ).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     waitFor fut
 
   test "withdraw: should guard against uninitialized state":
     let idSecretHash = generateCredentials().idSecretHash
 
-    try:
-      waitFor manager.withdraw(idSecretHash)
-    except CatchableError:
-      assert true
-    except Exception:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    let res = waitFor manager.withdraw(idSecretHash)
+
+    check:
+      res.isErr()
+      res.error == "OnchainGroupManager is not initialized"
 
   test "validateRoot: should validate good root":
     let idCredentials = generateCredentials()
@@ -217,10 +209,8 @@ suite "Onchain group manager":
     (waitFor manager.init()).isOkOr:
       raiseAssert $error
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned : " & getCurrentExceptionMsg()
 
     waitFor fut
 
@@ -299,10 +289,8 @@ suite "Onchain group manager":
 
     manager.onRegister(callback)
 
-    try:
-      waitFor manager.register(credentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    (waitFor manager.register(credentials, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
     waitFor fut
 
     let rootUpdated = waitFor manager.updateRoots()
@@ -337,11 +325,8 @@ suite "Onchain group manager":
 
     let idCredential = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredential, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling startGroupSync: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredential, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     let messageBytes = "Hello".toBytes()
 
@@ -395,14 +380,12 @@ suite "Onchain group manager":
 
       return callback
 
-    try:
-      manager.onRegister(generateCallback(futures, credentials))
+    manager.onRegister(generateCallback(futures, credentials))
 
-      for i in 0 ..< credentials.len():
-        waitFor manager.register(credentials[i], UserMessageLimit(20))
-        discard waitFor manager.updateRoots()
-    except Exception, CatchableError:
-      assert false, "exception raised: " & getCurrentExceptionMsg()
+    for i in 0 ..< credentials.len():
+      (waitFor manager.register(credentials[i], UserMessageLimit(20))).isOkOr:
+        assert false, "Failed to register credential " & $i & ": " & error
+      discard waitFor manager.updateRoots()
 
     waitFor allFutures(futures)
 
diff --git a/tests/waku_rln_relay/test_waku_rln_relay.nim b/tests/waku_rln_relay/test_waku_rln_relay.nim
index d9fe0d890..e41b79608 100644
--- a/tests/waku_rln_relay/test_waku_rln_relay.nim
+++ b/tests/waku_rln_relay/test_waku_rln_relay.nim
@@ -242,11 +242,8 @@ suite "Waku rln relay":
     let manager = cast[OnchainGroupManager](wakuRlnRelay.groupManager)
     let idCredentials = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     let epoch1 = wakuRlnRelay.getCurrentEpoch()
 
@@ -301,11 +298,8 @@ suite "Waku rln relay":
     let manager = cast[OnchainGroupManager](wakuRlnRelay.groupManager)
     let idCredentials = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "error returned when calling register: " & error
 
     # usually it's 20 seconds but we set it to 1 for testing purposes which make the test faster
     wakuRlnRelay.rlnMaxTimestampGap = 1
@@ -353,11 +347,9 @@ suite "Waku rln relay":
     let manager1 = cast[OnchainGroupManager](wakuRlnRelay1.groupManager)
     let idCredentials1 = generateCredentials()
 
-    try:
-      waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-    except Exception, CatchableError:
+    (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
       assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+        "error returned when calling register: " & error
 
     let index2 = MembershipIndex(6)
     let rlnConf2 = getWakuRlnConfig(manager = manager, index = index2)
@@ -369,11 +361,9 @@ suite "Waku rln relay":
     let manager2 = cast[OnchainGroupManager](wakuRlnRelay2.groupManager)
     let idCredentials2 = generateCredentials()
 
-    try:
-      waitFor manager2.register(idCredentials2, UserMessageLimit(20))
-    except Exception, CatchableError:
+    (waitFor manager2.register(idCredentials2, UserMessageLimit(20))).isOkOr:
       assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+        "error returned when calling register: " & error
 
     # get the current epoch time
     let epoch = wakuRlnRelay1.getCurrentEpoch()
diff --git a/tests/waku_rln_relay/test_wakunode_rln_relay.nim b/tests/waku_rln_relay/test_wakunode_rln_relay.nim
index fcf97a671..79a4d6711 100644
--- a/tests/waku_rln_relay/test_wakunode_rln_relay.nim
+++ b/tests/waku_rln_relay/test_wakunode_rln_relay.nim
@@ -58,11 +58,8 @@ procSuite "WakuNode - RLN relay":
       let manager1 = cast[OnchainGroupManager](node1.wakuRlnRelay.groupManager)
       let idCredentials1 = generateCredentials()
 
-      try:
-        waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-      except Exception, CatchableError:
-        assert false,
-          "exception raised when calling register: " & getCurrentExceptionMsg()
+      (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
+        assert false, "error returned when calling register: " & error
 
       let rootUpdated1 = waitFor manager1.updateRoots()
       info "Updated root for node1", rootUpdated1
@@ -172,11 +169,8 @@ procSuite "WakuNode - RLN relay":
       let manager1 = cast[OnchainGroupManager](node1.wakuRlnRelay.groupManager)
       let idCredentials1 = generateCredentials()
 
-      try:
-        waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-      except Exception, CatchableError:
-        assert false,
-          "exception raised when calling register: " & getCurrentExceptionMsg()
+      (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
+        assert false, "error returned when calling register: " & error
 
       let rootUpdated1 = waitFor manager1.updateRoots()
       info "Updated root for node", node = 1, rootUpdated = rootUpdated1
@@ -192,11 +186,8 @@ procSuite "WakuNode - RLN relay":
       let manager2 = cast[OnchainGroupManager](node2.wakuRlnRelay.groupManager)
       let idCredentials2 = generateCredentials()
 
-      try:
-        waitFor manager2.register(idCredentials2, UserMessageLimit(20))
-      except Exception, CatchableError:
-        assert false,
-          "exception raised when calling register: " & getCurrentExceptionMsg()
+      (waitFor manager2.register(idCredentials2, UserMessageLimit(20))).isOkOr:
+        assert false, "error returned when calling register: " & error
 
       let rootUpdated2 = waitFor manager2.updateRoots()
       info "Updated root for node", node = 2, rootUpdated = rootUpdated2
@@ -212,11 +203,8 @@ procSuite "WakuNode - RLN relay":
       let manager3 = cast[OnchainGroupManager](node3.wakuRlnRelay.groupManager)
       let idCredentials3 = generateCredentials()
 
-      try:
-        waitFor manager3.register(idCredentials3, UserMessageLimit(20))
-      except Exception, CatchableError:
-        assert false,
-          "exception raised when calling register: " & getCurrentExceptionMsg()
+      (waitFor manager3.register(idCredentials3, UserMessageLimit(20))).isOkOr:
+        assert false, "error returned when calling register: " & error
 
       let rootUpdated3 = waitFor manager3.updateRoots()
       info "Updated root for node", node = 3, rootUpdated = rootUpdated3
@@ -333,11 +321,8 @@ procSuite "WakuNode - RLN relay":
       let manager1 = cast[OnchainGroupManager](node1.wakuRlnRelay.groupManager)
       let idCredentials1 = generateCredentials()
 
-      try:
-        waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-      except Exception, CatchableError:
-        assert false,
-          "exception raised when calling register: " & getCurrentExceptionMsg()
+      (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
+        assert false, "error returned when calling register: " & error
 
       let rootUpdated1 = waitFor manager1.updateRoots()
       info "Updated root for node1", rootUpdated1
@@ -448,11 +433,8 @@ procSuite "WakuNode - RLN relay":
       let manager1 = cast[OnchainGroupManager](node1.wakuRlnRelay.groupManager)
       let idCredentials1 = generateCredentials()
 
-      try:
-        waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-      except Exception, CatchableError:
-        assert false,
-          "exception raised when calling register: " & getCurrentExceptionMsg()
+      (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
+        assert false, "error returned when calling register: " & error
 
       let rootUpdated1 = waitFor manager1.updateRoots()
       info "Updated root for node1", rootUpdated1
@@ -620,11 +602,8 @@ procSuite "WakuNode - RLN relay":
       let manager1 = cast[OnchainGroupManager](node1.wakuRlnRelay.groupManager)
       let idCredentials1 = generateCredentials()
 
-      try:
-        waitFor manager1.register(idCredentials1, UserMessageLimit(20))
-      except Exception, CatchableError:
-        assert false,
-          "exception raised when calling register: " & getCurrentExceptionMsg()
+      (waitFor manager1.register(idCredentials1, UserMessageLimit(20))).isOkOr:
+        assert false, "error returned when calling register: " & error
 
       let rootUpdated1 = waitFor manager1.updateRoots()
       info "Updated root for node1", rootUpdated1
diff --git a/tests/wakunode_rest/test_rest_relay.nim b/tests/wakunode_rest/test_rest_relay.nim
index f16e5c4f4..efdd597ba 100644
--- a/tests/wakunode_rest/test_rest_relay.nim
+++ b/tests/wakunode_rest/test_rest_relay.nim
@@ -42,8 +42,8 @@ suite "Waku v2 Rest API - Relay":
   var manager {.threadVar.}: OnchainGroupManager
 
   setup:
-    anvilProc = runAnvil()
-    manager = waitFor setupOnchainGroupManager()
+    anvilProc = runAnvil(stateFile = some(DEFAULT_ANVIL_STATE_PATH))
+    manager = waitFor setupOnchainGroupManager(deployContracts = false)
 
   teardown:
     stopAnvil(anvilProc)
@@ -268,11 +268,8 @@ suite "Waku v2 Rest API - Relay":
     let manager = cast[OnchainGroupManager](node.wakuRlnRelay.groupManager)
     let idCredentials = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "Failed to register identity credentials" & getCurrentExceptionMsg()
 
     let rootUpdated = waitFor manager.updateRoots()
     info "Updated root for node", rootUpdated
@@ -545,11 +542,8 @@ suite "Waku v2 Rest API - Relay":
     let manager = cast[OnchainGroupManager](node.wakuRlnRelay.groupManager)
     let idCredentials = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "Failed to register identity credentials" & getCurrentExceptionMsg()
 
     let rootUpdated = waitFor manager.updateRoots()
     info "Updated root for node", rootUpdated
@@ -617,11 +611,8 @@ suite "Waku v2 Rest API - Relay":
     let manager = cast[OnchainGroupManager](node.wakuRlnRelay.groupManager)
     let idCredentials = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "Failed to register identity credentials" & getCurrentExceptionMsg()
 
     let rootUpdated = waitFor manager.updateRoots()
     info "Updated root for node", rootUpdated
@@ -679,11 +670,8 @@ suite "Waku v2 Rest API - Relay":
     let manager = cast[OnchainGroupManager](node.wakuRlnRelay.groupManager)
     let idCredentials = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "Failed to register identity credentials" & getCurrentExceptionMsg()
 
     let rootUpdated = waitFor manager.updateRoots()
     info "Updated root for node", rootUpdated
@@ -754,11 +742,8 @@ suite "Waku v2 Rest API - Relay":
     let manager = cast[OnchainGroupManager](node.wakuRlnRelay.groupManager)
     let idCredentials = generateCredentials()
 
-    try:
-      waitFor manager.register(idCredentials, UserMessageLimit(20))
-    except Exception, CatchableError:
-      assert false,
-        "exception raised when calling register: " & getCurrentExceptionMsg()
+    (waitFor manager.register(idCredentials, UserMessageLimit(20))).isOkOr:
+      assert false, "Failed to register identity credentials" & getCurrentExceptionMsg()
 
     let rootUpdated = waitFor manager.updateRoots()
     info "Updated root for node", rootUpdated
diff --git a/tools/rln_keystore_generator/rln_keystore_generator.nim b/tools/rln_keystore_generator/rln_keystore_generator.nim
index 85df37982..503e8d58e 100644
--- a/tools/rln_keystore_generator/rln_keystore_generator.nim
+++ b/tools/rln_keystore_generator/rln_keystore_generator.nim
@@ -73,7 +73,9 @@ proc doRlnKeystoreGenerator*(conf: RlnKeystoreGeneratorConf) =
 
   # 4. register on-chain
   try:
-    waitFor groupManager.register(credential, conf.userMessageLimit)
+    (waitFor groupManager.register(credential, conf.userMessageLimit)).isOkOr:
+      error "Failed to register on-chain", error = error
+      quit(QuitFailure)
   except Exception, CatchableError:
     error "failure while registering credentials on-chain",
       error = getCurrentExceptionMsg()
diff --git a/waku/waku_rln_relay/group_manager/group_manager_base.nim b/waku/waku_rln_relay/group_manager/group_manager_base.nim
index de2962e42..9c088d4c5 100644
--- a/waku/waku_rln_relay/group_manager/group_manager_base.nim
+++ b/waku/waku_rln_relay/group_manager/group_manager_base.nim
@@ -144,6 +144,4 @@ method generateProof*(
   return err("generateProof is not implemented")
 
 method isReady*(g: GroupManager): Future[bool] {.base, async.} =
-  raise newException(
-    CatchableError, "isReady proc for " & $g.type & " is not implemented yet"
-  )
+  return true
diff --git a/waku/waku_rln_relay/group_manager/on_chain/group_manager.nim b/waku/waku_rln_relay/group_manager/on_chain/group_manager.nim
index 2ce7d4423..2e4882891 100644
--- a/waku/waku_rln_relay/group_manager/on_chain/group_manager.nim
+++ b/waku/waku_rln_relay/group_manager/on_chain/group_manager.nim
@@ -50,109 +50,85 @@ type
 proc fetchMerkleProofElements*(
     g: OnchainGroupManager
 ): Future[Result[seq[byte], string]] {.async.} =
-  try:
-    let membershipIndex = g.membershipIndex.get()
-    let index40 = stuint(membershipIndex, 40)
+  let membershipIndex = g.membershipIndex.get()
+  let index40 = stuint(membershipIndex, 40)
 
-    let methodSig = "getMerkleProof(uint40)"
-    var paddedParam = newSeq[byte](32)
-    let indexBytes = index40.toBytesBE()
-    for i in 0 ..< min(indexBytes.len, paddedParam.len):
-      paddedParam[paddedParam.len - indexBytes.len + i] = indexBytes[i]
+  let methodSig = "getMerkleProof(uint40)"
+  var paddedParam = newSeq[byte](32)
+  let indexBytes = index40.toBytesBE()
+  for i in 0 ..< min(indexBytes.len, paddedParam.len):
+    paddedParam[paddedParam.len - indexBytes.len + i] = indexBytes[i]
 
-    let response = await sendEthCallWithParams(
-      ethRpc = g.ethRpc.get(),
-      functionSignature = methodSig,
-      params = paddedParam,
-      fromAddress = g.ethRpc.get().defaultAccount,
-      toAddress = fromHex(Address, g.ethContractAddress),
-      chainId = g.chainId,
-    )
+  let response = await sendEthCallWithParams(
+    ethRpc = g.ethRpc.get(),
+    functionSignature = methodSig,
+    params = paddedParam,
+    fromAddress = g.ethRpc.get().defaultAccount,
+    toAddress = fromHex(Address, g.ethContractAddress),
+    chainId = g.chainId,
+  )
 
-    return response
-  except CatchableError:
-    error "Failed to fetch Merkle proof elements", error = getCurrentExceptionMsg()
-    return err("Failed to fetch merkle proof elements: " & getCurrentExceptionMsg())
+  return response
 
 proc fetchMerkleRoot*(
     g: OnchainGroupManager
 ): Future[Result[UInt256, string]] {.async.} =
-  try:
-    let merkleRoot = await sendEthCallWithoutParams(
-      ethRpc = g.ethRpc.get(),
-      functionSignature = "root()",
-      fromAddress = g.ethRpc.get().defaultAccount,
-      toAddress = fromHex(Address, g.ethContractAddress),
-      chainId = g.chainId,
-    )
-    return merkleRoot
-  except CatchableError:
-    error "Failed to fetch Merkle root", error = getCurrentExceptionMsg()
-    return err("Failed to fetch merkle root: " & getCurrentExceptionMsg())
+  let merkleRoot = await sendEthCallWithoutParams(
+    ethRpc = g.ethRpc.get(),
+    functionSignature = "root()",
+    fromAddress = g.ethRpc.get().defaultAccount,
+    toAddress = fromHex(Address, g.ethContractAddress),
+    chainId = g.chainId,
+  )
+  return merkleRoot
 
 proc fetchNextFreeIndex*(
     g: OnchainGroupManager
 ): Future[Result[UInt256, string]] {.async.} =
-  try:
-    let nextFreeIndex = await sendEthCallWithoutParams(
-      ethRpc = g.ethRpc.get(),
-      functionSignature = "nextFreeIndex()",
-      fromAddress = g.ethRpc.get().defaultAccount,
-      toAddress = fromHex(Address, g.ethContractAddress),
-      chainId = g.chainId,
-    )
-    return nextFreeIndex
-  except CatchableError:
-    error "Failed to fetch next free index", error = getCurrentExceptionMsg()
-    return err("Failed to fetch next free index: " & getCurrentExceptionMsg())
+  let nextFreeIndex = await sendEthCallWithoutParams(
+    ethRpc = g.ethRpc.get(),
+    functionSignature = "nextFreeIndex()",
+    fromAddress = g.ethRpc.get().defaultAccount,
+    toAddress = fromHex(Address, g.ethContractAddress),
+    chainId = g.chainId,
+  )
+  return nextFreeIndex
 
 proc fetchMembershipStatus*(
     g: OnchainGroupManager, idCommitment: IDCommitment
 ): Future[Result[bool, string]] {.async.} =
-  try:
-    let params = idCommitment.reversed()
-    let responseBytes = (
-      await sendEthCallWithParams(
-        ethRpc = g.ethRpc.get(),
-        functionSignature = "isInMembershipSet(uint256)",
-        params = params,
-        fromAddress = g.ethRpc.get().defaultAccount,
-        toAddress = fromHex(Address, g.ethContractAddress),
-        chainId = g.chainId,
-      )
-    ).valueOr:
-      return err("Failed to check membership: " & error)
-
-    return ok(responseBytes.len == 32 and responseBytes[^1] == 1'u8)
-  except CatchableError:
-    error "Failed to fetch membership set membership", error = getCurrentExceptionMsg()
-    return err("Failed to fetch membership set membership: " & getCurrentExceptionMsg())
-
-proc fetchMaxMembershipRateLimit*(
-    g: OnchainGroupManager
-): Future[Result[UInt256, string]] {.async.} =
-  try:
-    let maxMembershipRateLimit = await sendEthCallWithoutParams(
+  let params = idCommitment.reversed()
+  let responseBytes = (
+    await sendEthCallWithParams(
       ethRpc = g.ethRpc.get(),
-      functionSignature = "maxMembershipRateLimit()",
+      functionSignature = "isInMembershipSet(uint256)",
+      params = params,
       fromAddress = g.ethRpc.get().defaultAccount,
       toAddress = fromHex(Address, g.ethContractAddress),
       chainId = g.chainId,
     )
-    return maxMembershipRateLimit
-  except CatchableError:
-    error "Failed to fetch max membership rate limit", error = getCurrentExceptionMsg()
-    return err("Failed to fetch max membership rate limit: " & getCurrentExceptionMsg())
+  ).valueOr:
+    return err("Failed to check membership: " & error)
 
-template initializedGuard(g: OnchainGroupManager): untyped =
+  return ok(responseBytes.len == 32 and responseBytes[^1] == 1'u8)
+
+proc fetchMaxMembershipRateLimit*(
+    g: OnchainGroupManager
+): Future[Result[UInt256, string]] {.async.} =
+  let maxMembershipRateLimit = await sendEthCallWithoutParams(
+    ethRpc = g.ethRpc.get(),
+    functionSignature = "maxMembershipRateLimit()",
+    fromAddress = g.ethRpc.get().defaultAccount,
+    toAddress = fromHex(Address, g.ethContractAddress),
+    chainId = g.chainId,
+  )
+
+  return maxMembershipRateLimit
+
+proc checkInitialized(g: OnchainGroupManager): Result[void, string] =
   if not g.initialized:
-    raise newException(CatchableError, "OnchainGroupManager is not initialized")
-
-template retryWrapper(
-    g: OnchainGroupManager, res: auto, errStr: string, body: untyped
-): auto =
-  retryWrapper(res, RetryStrategy.new(), errStr, g.onFatalErrorAction):
-    body
+    return err("OnchainGroupManager is not initialized")
+  return ok()
 
 proc updateRoots*(g: OnchainGroupManager): Future[bool] {.async.} =
   let rootRes = (await g.fetchMerkleRoot()).valueOr:
@@ -172,40 +148,37 @@ proc updateRoots*(g: OnchainGroupManager): Future[bool] {.async.} =
 
   return false
 
-proc trackRootChanges*(g: OnchainGroupManager) {.async: (raises: [CatchableError]).} =
-  try:
-    initializedGuard(g)
-    const rpcDelay = 5.seconds
+proc trackRootChanges*(g: OnchainGroupManager): Future[Result[void, string]] {.async.} =
+  ?checkInitialized(g)
 
-    while true:
-      await sleepAsync(rpcDelay)
-      let rootUpdated = await g.updateRoots()
+  const rpcDelay = 5.seconds
 
-      if rootUpdated:
-        ## The membership set on-chain has changed (some new members have joined or some members have left)
-        if g.membershipIndex.isSome():
-          ## A membership index exists only if the node has registered with RLN.
-          ## Non-registered nodes cannot have Merkle proof elements.
-          let proofResult = await g.fetchMerkleProofElements()
-          if proofResult.isErr():
-            error "Failed to fetch Merkle proof", error = proofResult.error
-          else:
-            g.merkleProofCache = proofResult.get()
+  while true:
+    await sleepAsync(rpcDelay)
+    let rootUpdated = await g.updateRoots()
 
-        let nextFreeIndex = (await g.fetchNextFreeIndex()).valueOr:
-          error "Failed to fetch next free index", error = error
-          raise
-            newException(CatchableError, "Failed to fetch next free index: " & error)
+    if rootUpdated:
+      ## The membership set on-chain has changed (some new members have joined or some members have left)
+      if g.membershipIndex.isSome():
+        ## A membership index exists only if the node has registered with RLN.
+        ## Non-registered nodes cannot have Merkle proof elements.
+        let proofResult = await g.fetchMerkleProofElements()
+        if proofResult.isErr():
+          error "Failed to fetch Merkle proof", error = proofResult.error
+        else:
+          g.merkleProofCache = proofResult.get()
 
-        let memberCount = cast[int64](nextFreeIndex)
-        waku_rln_number_registered_memberships.set(float64(memberCount))
-  except CatchableError:
-    error "Fatal error in trackRootChanges", error = getCurrentExceptionMsg()
+      let nextFreeIndex = (await g.fetchNextFreeIndex()).valueOr:
+        error "Failed to fetch next free index", error = error
+        return err("Failed to fetch next free index: " & error)
+
+      let memberCount = cast[int64](nextFreeIndex)
+      waku_rln_number_registered_memberships.set(float64(memberCount))
 
 method register*(
     g: OnchainGroupManager, rateCommitment: RateCommitment
-): Future[void] {.async: (raises: [Exception]).} =
-  initializedGuard(g)
+): Future[Result[void, string]] {.async.} =
+  ?checkInitialized(g)
 
   try:
     let leaf = rateCommitment.toLeaf().get()
@@ -214,33 +187,40 @@ method register*(
       info "registering member via callback", rateCommitment = leaf, index = idx
       await g.registerCb.get()(@[Membership(rateCommitment: leaf, index: idx)])
     g.latestIndex.inc()
-  except CatchableError:
-    raise newException(ValueError, getCurrentExceptionMsg())
+  except Exception as e:
+    return err("Failed to call register callback: " & e.msg)
+
+  return ok()
 
 method register*(
     g: OnchainGroupManager,
     identityCredential: IdentityCredential,
     userMessageLimit: UserMessageLimit,
-): Future[void] {.async: (raises: [Exception]).} =
-  initializedGuard(g)
+): Future[Result[void, string]] {.async.} =
+  ?checkInitialized(g)
 
   let ethRpc = g.ethRpc.get()
   let wakuRlnContract = g.wakuRlnContract.get()
 
-  var gasPrice: int
-  g.retryWrapper(gasPrice, "Failed to get gas price"):
-    let fetchedGasPrice = uint64(await ethRpc.provider.eth_gasPrice())
-    ## Multiply by 2 to speed up the transaction
-    ## Check for overflow when casting to int
-    if fetchedGasPrice > uint64(high(int) div 2):
-      warn "Gas price overflow detected, capping at maximum int value",
-        fetchedGasPrice = fetchedGasPrice, maxInt = high(int)
-      high(int)
-    else:
-      let calculatedGasPrice = int(fetchedGasPrice) * 2
-      debug "Gas price calculated",
-        fetchedGasPrice = fetchedGasPrice, gasPrice = calculatedGasPrice
-      calculatedGasPrice
+  let gasPrice = (
+    await retryWrapper(
+      RetryStrategy.new(),
+      "Failed to get gas price",
+      proc(): Future[int] {.async.} =
+        let fetchedGasPrice = uint64(await ethRpc.provider.eth_gasPrice())
+        if fetchedGasPrice > uint64(high(int) div 2):
+          warn "Gas price overflow detected, capping at maximum int value",
+            fetchedGasPrice = fetchedGasPrice, maxInt = high(int)
+          return high(int)
+        else:
+          let calculatedGasPrice = int(fetchedGasPrice) * 2
+          debug "Gas price calculated",
+            fetchedGasPrice = fetchedGasPrice, gasPrice = calculatedGasPrice
+          return calculatedGasPrice,
+    )
+  ).valueOr:
+    return err("Failed to get gas price: " & error)
+
   let idCommitmentHex = identityCredential.idCommitment.inHex()
   debug "identityCredential idCommitmentHex", idCommitment = idCommitmentHex
   let idCommitment = identityCredential.idCommitment.toUInt256()
@@ -249,27 +229,37 @@ method register*(
     idCommitment = idCommitment,
     userMessageLimit = userMessageLimit,
     idCommitmentsToErase = idCommitmentsToErase
-  var txHash: TxHash
-  g.retryWrapper(txHash, "Failed to register the member"):
-    await wakuRlnContract
-    .register(idCommitment, userMessageLimit.stuint(32), idCommitmentsToErase)
-    .send(gasPrice = gasPrice)
+  let txHash = (
+    await retryWrapper(
+      RetryStrategy.new(),
+      "Failed to register the member",
+      proc(): Future[TxHash] {.async.} =
+        return await wakuRlnContract
+        .register(idCommitment, userMessageLimit.stuint(32), idCommitmentsToErase)
+        .send(gasPrice = gasPrice),
+    )
+  ).valueOr:
+    return err("Failed to register member: " & error)
 
   # wait for the transaction to be mined
-  var tsReceipt: ReceiptObject
-  g.retryWrapper(tsReceipt, "Failed to get the transaction receipt"):
-    await ethRpc.getMinedTransactionReceipt(txHash)
+  let tsReceipt = (
+    await retryWrapper(
+      RetryStrategy.new(),
+      "Failed to get the transaction receipt",
+      proc(): Future[ReceiptObject] {.async.} =
+        return await ethRpc.getMinedTransactionReceipt(txHash),
+    )
+  ).valueOr:
+    return err("Failed to get transaction receipt: " & error)
   debug "registration transaction mined", txHash = txHash
   g.registrationTxHash = some(txHash)
   # the receipt topic holds the hash of signature of the raised events
   debug "ts receipt", receipt = tsReceipt[]
 
   if tsReceipt.status.isNone():
-    raise newException(ValueError, "Transaction failed: status is None")
+    return err("Transaction failed: status is None")
   if tsReceipt.status.get() != 1.Quantity:
-    raise newException(
-      ValueError, "Transaction failed with status: " & $tsReceipt.status.get()
-    )
+    return err("Transaction failed with status: " & $tsReceipt.status.get())
 
   ## Search through all transaction logs to find the MembershipRegistered event
   let expectedEventSignature = cast[FixedBytes[32]](keccak.keccak256.digest(
@@ -283,9 +273,7 @@ method register*(
       break
 
   if membershipRegisteredLog.isNone():
-    raise newException(
-      ValueError, "register: MembershipRegistered event not found in transaction logs"
-    )
+    return err("register: MembershipRegistered event not found in transaction logs")
 
   let registrationLog = membershipRegisteredLog.get()
 
@@ -309,20 +297,28 @@ method register*(
 
   if g.registerCb.isSome():
     let member = Membership(rateCommitment: rateCommitment, index: g.latestIndex)
-    await g.registerCb.get()(@[member])
+    try:
+      await g.registerCb.get()(@[member])
+    except Exception as e:
+      return err("Failed to call register callback: " & e.msg)
   g.latestIndex.inc()
 
-  return
+  return ok()
 
 method withdraw*(
     g: OnchainGroupManager, idCommitment: IDCommitment
-): Future[void] {.async: (raises: [Exception]).} =
-  initializedGuard(g) # TODO: after slashing is enabled on the contract
+): Future[Result[void, string]] {.async.} =
+  checkInitialized(g).isOkOr:
+    return err(error)
+  return ok()
 
 method withdrawBatch*(
     g: OnchainGroupManager, idCommitments: seq[IDCommitment]
-): Future[void] {.async: (raises: [Exception]).} =
-  initializedGuard(g)
+): Future[Result[void, string]] {.async.} =
+  checkInitialized(g).isOkOr:
+    return err(error)
+
+  return ok()
 
 proc getRootFromProofAndIndex(
     g: OnchainGroupManager, elements: seq[byte], bits: seq[byte]
@@ -354,7 +350,7 @@ method generateProof*(
     epoch: Epoch,
     messageId: MessageId,
     rlnIdentifier = DefaultRlnIdentifier,
-): GroupManagerResult[RateLimitProof] {.gcsafe, raises: [].} =
+): GroupManagerResult[RateLimitProof] {.gcsafe.} =
   ## Generates an RLN proof using the cached Merkle proof and custom witness
   # Ensure identity credentials and membership index are set
   if g.idCredentials.isNone():
@@ -452,7 +448,7 @@ method generateProof*(
 
 method verifyProof*(
     g: OnchainGroupManager, input: seq[byte], proof: RateLimitProof
-): GroupManagerResult[bool] {.gcsafe, raises: [].} =
+): GroupManagerResult[bool] {.gcsafe.} =
   ## -- Verifies an RLN rate-limit proof against the set of valid Merkle roots --
 
   var normalizedProof = proof
@@ -492,25 +488,31 @@ method onWithdraw*(g: OnchainGroupManager, cb: OnWithdrawCallback) {.gcsafe.} =
 proc establishConnection(
     g: OnchainGroupManager
 ): Future[GroupManagerResult[Web3]] {.async.} =
-  var ethRpc: Web3
+  let ethRpc = (
+    await retryWrapper(
+      RetryStrategy.new(),
+      "Failed to connect to the Ethereum client",
+      proc(): Future[Web3] {.async.} =
+        var innerEthRpc: Web3
+        var connected = false
+        for clientUrl in g.ethClientUrls:
+          ## We give a chance to the user to provide multiple clients
+          ## and we try to connect to each of them
+          try:
+            innerEthRpc = await newWeb3(clientUrl)
+            connected = true
+            break
+          except CatchableError:
+            error "failed connect Eth client", error = getCurrentExceptionMsg()
 
-  g.retryWrapper(ethRpc, "Failed to connect to the Ethereum client"):
-    var innerEthRpc: Web3
-    var connected = false
-    for clientUrl in g.ethClientUrls:
-      ## We give a chance to the user to provide multiple clients
-      ## and we try to connect to each of them
-      try:
-        innerEthRpc = await newWeb3(clientUrl)
-        connected = true
-        break
-      except CatchableError:
-        error "failed connect Eth client", error = getCurrentExceptionMsg()
+        ## this exception is handled by the retrywrapper
+        if not connected:
+          raise newException(CatchableError, "all failed")
 
-    if not connected:
-      raise newException(CatchableError, "all failed")
-
-    innerEthRpc
+        return innerEthRpc,
+    )
+  ).valueOr:
+    return err("Failed to establish Ethereum connection: " & error)
 
   return ok(ethRpc)
 
@@ -519,9 +521,15 @@ method init*(g: OnchainGroupManager): Future[GroupManagerResult[void]] {.async.}
   let ethRpc: Web3 = (await establishConnection(g)).valueOr:
     return err("failed to connect to Ethereum clients: " & $error)
 
-  var fetchedChainId: UInt256
-  g.retryWrapper(fetchedChainId, "Failed to get the chain id"):
-    await ethRpc.provider.eth_chainId()
+  let fetchedChainId = (
+    await retryWrapper(
+      RetryStrategy.new(),
+      "Failed to get the chain id",
+      proc(): Future[UInt256] {.async.} =
+        return await ethRpc.provider.eth_chainId(),
+    )
+  ).valueOr:
+    return err("Failed to get chain id: " & error)
 
   # Set the chain id
   if g.chainId == 0:
@@ -595,8 +603,10 @@ method init*(g: OnchainGroupManager): Future[GroupManagerResult[void]] {.async.}
   proc onDisconnect() {.async.} =
     error "Ethereum client disconnected"
 
-    var newEthRpc: Web3 = (await g.establishConnection()).valueOr:
-      g.onFatalErrorAction("failed to connect to Ethereum clients onDisconnect")
+    let newEthRpc: Web3 = (await g.establishConnection()).valueOr:
+      error "Fatal: failed to reconnect to Ethereum clients after disconnect",
+        error = error
+      g.onFatalErrorAction("failed to reconnect to Ethereum clients: " & error)
       return
 
     newEthRpc.ondisconnect = ethRpc.ondisconnect
@@ -616,12 +626,14 @@ method stop*(g: OnchainGroupManager): Future[void] {.async, gcsafe.} =
   g.initialized = false
 
 method isReady*(g: OnchainGroupManager): Future[bool] {.async.} =
-  initializedGuard(g)
+  checkInitialized(g).isOkOr:
+    return false
 
   if g.ethRpc.isNone():
+    error "Ethereum RPC client is not configured"
     return false
 
   if g.wakuRlnContract.isNone():
+    error "Waku RLN contract is not configured"
     return false
-
   return true
diff --git a/waku/waku_rln_relay/group_manager/on_chain/retry_wrapper.nim b/waku/waku_rln_relay/group_manager/on_chain/retry_wrapper.nim
index df8716279..97bc0c435 100644
--- a/waku/waku_rln_relay/group_manager/on_chain/retry_wrapper.nim
+++ b/waku/waku_rln_relay/group_manager/on_chain/retry_wrapper.nim
@@ -1,36 +1,31 @@
-import ../../../common/error_handling
 import chronos
 import results
 
+const
+  DefaultRetryDelay* = 4000.millis
+  DefaultRetryCount* = 15'u
+
 type RetryStrategy* = object
-  shouldRetry*: bool
   retryDelay*: Duration
   retryCount*: uint
 
 proc new*(T: type RetryStrategy): RetryStrategy =
-  return RetryStrategy(shouldRetry: true, retryDelay: 4000.millis, retryCount: 15)
+  return RetryStrategy(retryDelay: DefaultRetryDelay, retryCount: DefaultRetryCount)
 
-template retryWrapper*(
-    res: auto,
-    retryStrategy: RetryStrategy,
-    errStr: string,
-    errCallback: OnFatalErrorHandler,
-    body: untyped,
-): auto =
-  if errCallback == nil:
-    raise newException(CatchableError, "Ensure that the errCallback is set")
+proc retryWrapper*[T](
+    retryStrategy: RetryStrategy, errStr: string, body: proc(): Future[T] {.async.}
+): Future[Result[T, string]] {.async.} =
   var retryCount = retryStrategy.retryCount
-  var shouldRetry = retryStrategy.shouldRetry
-  var exceptionMessage = ""
+  var lastError = ""
 
-  while shouldRetry and retryCount > 0:
+  while retryCount > 0:
     try:
-      res = body
-      shouldRetry = false
-    except:
+      let value = await body()
+      return ok(value)
+    except CatchableError as e:
       retryCount -= 1
-      exceptionMessage = getCurrentExceptionMsg()
-      await sleepAsync(retryStrategy.retryDelay)
-  if shouldRetry:
-    errCallback(errStr & ": " & exceptionMessage)
-    return
+      lastError = e.msg
+      if retryCount > 0:
+        await sleepAsync(retryStrategy.retryDelay)
+
+  return err(errStr & ": " & lastError)
diff --git a/waku/waku_rln_relay/rln_relay.nim b/waku/waku_rln_relay/rln_relay.nim
index 5c893e2a2..8559dcd66 100644
--- a/waku/waku_rln_relay/rln_relay.nim
+++ b/waku/waku_rln_relay/rln_relay.nim
@@ -68,7 +68,7 @@ type WakuRLNRelay* = ref object of RootObj
   onFatalErrorAction*: OnFatalErrorHandler
   nonceManager*: NonceManager
   epochMonitorFuture*: Future[void]
-  rootChangesFuture*: Future[void]
+  rootChangesFuture*: Future[Result[void, string]]
   brokerCtx*: BrokerContext
 
 proc calcEpoch*(rlnPeer: WakuRLNRelay, t: float64): Epoch =
@@ -467,7 +467,7 @@ proc mount(
 
   return ok(wakuRlnRelay)
 
-proc isReady*(rlnPeer: WakuRLNRelay): Future[bool] {.async: (raises: [Exception]).} =
+proc isReady*(rlnPeer: WakuRLNRelay): Future[bool] {.async.} =
   ## returns true if the rln-relay protocol is ready to relay messages
   ## returns false otherwise