feat(rln)!: generate contract types, migrate from ethers to viem #2705

adklempner · 2025-10-24T22:42:06Z

Problem / Description

Previous to this, the ABIs for the contracts were manually added to the rln package (not clear how).
Additionally, code related to calling the contracts was not typed, so any breaking changes to the ABI would not be detected at compile time.

Solution

Create a script that:

cloneshttps://github.com/waku-org/waku-rlnv2-contract
compiles it
uses the output to generate typesafe ABI code using wagmi

The rest of the code has been updated to use viem, which provides clean and typesafe ways to interact with the smart contracts.

Also adds new methods that were introduced in latest contract changes, specifically the ability to query for merkle root and merkle proof for a commitment directly from the smart contract.

Notes

Resolves feat(rln): replace manual smart contract classes/functions with generate typings #2630
Dogfooding PR: feat: use viem instead of ethers rln.waku.org#20

Checklist

Code changes are covered by unit tests.
Code changes are covered by e2e tests, if applicable.
Dogfooding has been performed, if feasible.
A test version has been published, if required.
All CI checks pass successfully.

github-actions · 2025-10-24T22:48:12Z

size-limit report 📦

Path	Size	Loading time (3g)	Running time (snapdragon)	Total time
Waku node	96.38 KB (0%)	2 s (0%)	1.5 s (-2.24% 🔽)	3.5 s
Waku Simple Light Node	147.7 KB (0%)	3 s (0%)	1.2 s (-13.1% 🔽)	4.2 s
ECIES encryption	22.62 KB (0%)	453 ms (0%)	284 ms (-45.27% 🔽)	736 ms
Symmetric encryption	22 KB (0%)	440 ms (0%)	335 ms (-36.28% 🔽)	775 ms
DNS discovery	52.17 KB (0%)	1.1 s (0%)	881 ms (-7.32% 🔽)	2 s
Peer Exchange discovery	52.91 KB (0%)	1.1 s (0%)	944 ms (+17.78% 🔺)	2.1 s
Peer Cache Discovery	46.64 KB (0%)	933 ms (0%)	953 ms (+103.53% 🔺)	1.9 s
Privacy preserving protocols	77.26 KB (0%)	1.6 s (0%)	1.4 s (+36.77% 🔺)	2.9 s
Waku Filter	79.78 KB (0%)	1.6 s (0%)	576 ms (-56.68% 🔽)	2.2 s
Waku LightPush	78 KB (0%)	1.6 s (0%)	1.1 s (-14.21% 🔽)	2.7 s
History retrieval protocols	83.66 KB (0%)	1.7 s (0%)	1.1 s (-38.76% 🔽)	2.7 s
Deterministic Message Hashing	28.98 KB (0%)	580 ms (0%)	751 ms (+63.88% 🔺)	1.4 s

packages/rln/tsconfig.json

Copilot

Pull Request Overview

This PR migrates the RLN package from ethers.js to viem for Ethereum interactions and introduces automated contract type generation using wagmi CLI. The changes enable type-safe contract interactions by generating TypeScript bindings directly from the smart contract ABIs.

Key changes:

Replaced ethers.js with viem for all blockchain interactions
Automated ABI generation via wagmi CLI from waku-rlnv2-contract repository
Updated all contract interaction code to use viem's type-safe APIs
Added new methods for querying merkle root and merkle proof directly from contracts

Reviewed Changes

Copilot reviewed 21 out of 23 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
packages/rln/wagmi.config.ts	Configures wagmi CLI to generate TypeScript bindings from Foundry contracts
packages/rln/src/contract/wagmi/generated.ts	Auto-generated type-safe contract ABIs (977 lines)
packages/rln/src/contract/rln_base_contract.ts	Migrated from ethers Contract to viem getContract with type-safe reads/writes
packages/rln/src/utils/walletClient.ts	New utility to create viem client from window.ethereum
packages/rln/src/types.ts	Updated to use viem WalletClient instead of ethers.Signer
packages/rln/generate_contract_abi.sh	Shell script to clone, build, and generate contract types
packages/rln/package.json	Removed ethers dependency, added viem and wagmi tooling

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packages/rln/src/contract/types.ts

Copilot · 2025-11-12T11:56:12Z

packages/rln/src/contract/rln_base_contract.ts

+    const fromBlock = options.fromBlock
+      ? BigInt(options.fromBlock!)
+      : BigInt(this.deployBlock!);


Redundant non-null assertion after already checking with ternary operator. Line 195 uses options.fromBlock! after already checking options.fromBlock in the ternary condition. The non-null assertion is unnecessary here. Additionally, line 196 uses this.deployBlock! which could be undefined if the create() method hasn't been awaited, leading to a potential runtime error.

Suggested change

const fromBlock = options.fromBlock

? BigInt(options.fromBlock!)

: BigInt(this.deployBlock!);

let fromBlock: bigint;

if (options.fromBlock !== undefined) {

fromBlock = BigInt(options.fromBlock);

} else {

if (this.deployBlock === undefined) {

throw new Error("deployBlock is undefined. Ensure the contract is initialized and create() has been awaited before calling fetchMembers.");

}

fromBlock = BigInt(this.deployBlock);

}

Copilot · 2025-11-12T11:56:13Z

packages/rln/src/contract/rln_base_contract.ts

+    const registeredMemberEvents =
+      await this.contract.getEvents.MembershipRegistered({
+        fromBlock,
+        toBlock: fromBlock + BigInt(options.fetchRange!)


Missing null check for options.fetchRange. Lines 200, 204, and 209 use options.fetchRange! with non-null assertion, but there's no guarantee this value exists. This will cause undefined to be converted to NaN when passed to BigInt(), resulting in a runtime error.

reading it again, we don't actually need these events tracked with the new version of RLN smart contracts

perhaps we will, but I will re-implement when doing #2722

Copilot · 2025-11-12T11:56:13Z

packages/rln/src/contract/rln_base_contract.ts

-      return undefined;
-    }
+  private async getMemberIndex(idCommitmentBigInt: bigint): Promise<number> {
+    return (await this.contract.read.memberships([idCommitmentBigInt]))[5];


Magic number index [5] without explanation. Line 652 accesses array element at index 5 without documentation. According to the ABI at lines 573-584 in generated.ts, index 5 corresponds to the 'index' field of the membership struct. Consider adding a comment or using destructuring with named variables for clarity.

Suggested change

return (await this.contract.read.memberships([idCommitmentBigInt]))[5];

// According to the ABI, index 5 corresponds to the 'index' field of the membership struct

const [, , , , , index] = await this.contract.read.memberships([idCommitmentBigInt]);

return index;

packages/rln/src/contract/rln_base_contract.ts

packages/rln/generate_contract_abi.sh

Copilot · 2025-11-12T11:56:14Z

packages/rln/tsconfig.json

  "include": ["src"],
-  "exclude": ["src/**/*.spec.ts", "src/test_utils"]
-} 
+  "exclude": ["wagmi.config.ts"]


Removed exclusion of test files and test_utils. The original exclusion pattern [\"src/**/*.spec.ts\", \"src/test_utils\"] was removed and replaced with only [\"wagmi.config.ts\"]. This means test files and test utilities will now be included in the build output, which is likely unintended and could increase bundle size.

Suggested change

"exclude": ["wagmi.config.ts"]

"exclude": ["wagmi.config.ts", "src/**/*.spec.ts", "src/test_utils"]

Copilot · 2025-11-12T11:56:14Z

packages/rln/src/contract/rln_base_contract.ts

        return;
      }
-
+      const blockNumber = Number(evt.blockNumber);


Converting blockNumber to Number repeatedly in loop. Line 229 converts evt.blockNumber to Number inside the forEach loop (lines 225-256). If the block number exceeds JavaScript's MAX_SAFE_INTEGER (2^53-1), this conversion will lose precision. Consider keeping as bigint for accuracy or add a check for safe integer range.

current block number on linea sepolia is 20646374 so this shouldn't be an issue

Copilot

Pull Request Overview

Copilot reviewed 21 out of 23 changed files in this pull request and generated 4 comments.

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Copilot · 2025-11-12T21:06:11Z

packages/rln/src/contract/rln_base_contract.ts

+   * Withdraw deposited tokens after membership is erased
+   * @param token - Token address to withdraw
+   * NOTE: Funds are sent to msg.sender (the walletClient's address)


The comment on line 325 mentions that "Funds are sent to msg.sender (the walletClient's address)", but the function signature no longer includes a walletAddress parameter. This is a breaking API change that should be clearly documented. The previous implementation accepted walletAddress as a parameter but now it implicitly uses the wallet client's address. Consider noting this in the PR description or adding a migration guide.

Suggested change

* Withdraw deposited tokens after membership is erased

* @param token - Token address to withdraw

* NOTE: Funds are sent to msg.sender (the walletClient's address)

* Withdraw deposited tokens after membership is erased.

* @param token - Token address to withdraw

* @note Funds are sent to msg.sender (the walletClient's address).

* @breaking The `walletAddress` parameter has been removed. This function now always sends funds to the wallet client's address (`msg.sender`).

Copilot · 2025-11-12T21:06:12Z

packages/rln/README.md

+We use `wagmi` to generate TypeScript bindings for interacting with the RLN smart contracts. When changes are pushed to the `waku-rlnv2-contract` repository, run the following script to fetch and build the latest contracts and generate the TypeScript bindings:
+
+```
+./generate_contract_abi.sh


The script name in package.json is setup:contract-abi but the README refers to ./generate_contract_abi.sh. The npm script should be referenced instead for consistency: npm run setup:contract-abi

Suggested change

./generate_contract_abi.sh

npm run setup:contract-abi

Copilot · 2025-11-12T21:06:12Z

packages/rln/package.json

    "prepublish": "npm run build",
-    "reset-hard": "git clean -dfx -e .idea && git reset --hard && npm i && npm run build"
+    "reset-hard": "git clean -dfx -e .idea && git reset --hard && npm i && npm run build",
+    "setup:contract-abi": "./setup-contract-abi.sh",


The file path in the package.json script is ./setup-contract-abi.sh, but the actual file is named generate_contract_abi.sh. This mismatch will cause the script to fail when executed.

Suggested change

"setup:contract-abi": "./setup-contract-abi.sh",

"setup:contract-abi": "./generate_contract_abi.sh",

thank you robot

packages/rln/src/contract/rln_base_contract.ts

weboko · 2025-11-12T22:37:02Z

packages/rln/src/utils/rpcClient.ts

+    );
+  }
+
+  const [account] = await ethereum.request({ method: "eth_requestAccounts" });


this is not safe if .request doesn't resolve into array

looks like viem has a fully-typed polyfill for window which includes all the rpc requests, replacing with that

weboko · 2025-11-12T22:39:26Z

packages/rln/src/contract/constants.ts


 export const RLN_CONTRACT = {
  chainId: 59141,
  address: "0xb9cd878c90e49f797b4431fbf4fb333108cb90e6",


can we get these addresses from some other place similarly to abi?

Unfortunately no; we can move this elsewhere but this is a value that needs to be manually set for now.

weboko · 2025-11-12T22:40:47Z

packages/rln/package.json

-    "reset-hard": "git clean -dfx -e .idea && git reset --hard && npm i && npm run build"
+    "reset-hard": "git clean -dfx -e .idea && git reset --hard && npm i && npm run build",
+    "setup:contract-abi": "./setup-contract-abi.sh",
+    "generate:contract": "npx wagmi generate"


questions:

this command is not needed - if we have previous setup:contract-abi

how is setup:contract-abi supposed to run? before commit / build?

yes we can remove this one

it only needs to be run if the smart contracts are updated and we need to re-generate typings

weboko · 2025-11-12T22:43:33Z

packages/rln/generate_contract_abi.sh

@@ -0,0 +1,42 @@
+#!/bin/bash


this file is not cross platform and will not work on Windows

https://github.com/search?q=org%3Awaku-org+%23%21%2Fbin%2Fbash&type=code

¯_(ツ)_/¯

also, I can't imagine someone trying to make contributions to our repos without WSL, which should enable running bash...

weboko

good first iteration

left comments in addition to Copilot's

and make sure you properly integrate it with release CI

Copilot

Pull Request Overview

Copilot reviewed 21 out of 23 changed files in this pull request and generated 5 comments.

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packages/rln/generate_contract_abi.sh

packages/rln/src/contract/rln_base_contract.ts

adklempner force-pushed the feat/rln-contract-gen-types branch from 1fcf108 to a88dd8c Compare October 24, 2025 22:43

adklempner force-pushed the feat/rln-contract-gen-types branch from 264f2c0 to 5ea574e Compare October 27, 2025 20:48

This was referenced Oct 28, 2025

feat: use viem instead of ethers waku-org/rln.waku.org#20

Open

feat(rln): proof generation and verification #2716

Draft

adklempner force-pushed the feat/rln-contract-gen-types branch 3 times, most recently from 70922e5 to 7e5680f Compare November 11, 2025 21:42

adklempner marked this pull request as ready for review November 12, 2025 03:58

adklempner requested a review from a team as a code owner November 12, 2025 03:58

weboko requested a review from Copilot November 12, 2025 11:52

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adklempner added 6 commits November 12, 2025 17:33

feat: use wagmi to generate contract types

91c27be

feat: migrate rln from ethers to viem

daaa119

fix: remove .gitmodules

d1f1fb5

fix: update readme

698b8da

fix: refactor to use a single viem client object

bcfff1c

fix: update comments, tsconfig

65f1e74

adklempner added 4 commits November 12, 2025 17:33

feat: remove membership event tracking

b05020c

fix: script name in package.json and readme

9df5fb4

fix: only allow linea sepolia

fae6d29

fix: consolidate viem types, typed window

e0c6a09

adklempner force-pushed the feat/rln-contract-gen-types branch from 93c152a to e0c6a09 Compare November 13, 2025 01:37

adklempner requested a review from Copilot November 13, 2025 01:39

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Copilot finished reviewing on behalf of adklempner November 13, 2025 01:41

Copilot AI reviewed Nov 13, 2025

View reviewed changes

fix: use viem to infer type of decoded event

44ad556

-    const fromBlock = options.fromBlock
-      ? BigInt(options.fromBlock!)
-      : BigInt(this.deployBlock!);
+    let fromBlock: bigint;
+    if (options.fromBlock !== undefined) {
+      fromBlock = BigInt(options.fromBlock);
+    } else {
+      if (this.deployBlock === undefined) {
+        throw new Error("deployBlock is undefined. Ensure the contract is initialized and create() has been awaited before calling fetchMembers.");
+      }
+      fromBlock = BigInt(this.deployBlock);
+    }

-    return (await this.contract.read.memberships([idCommitmentBigInt]))[5];
+    // According to the ABI, index 5 corresponds to the 'index' field of the membership struct
+    const [, , , , , index] = await this.contract.read.memberships([idCommitmentBigInt]);
+    return index;

	"exclude": ["wagmi.config.ts"]
	"exclude": ["wagmi.config.ts", "src/*/.spec.ts", "src/test_utils"]

	"setup:contract-abi": "./setup-contract-abi.sh",
	"setup:contract-abi": "./generate_contract_abi.sh",

feat(rln)!: generate contract types, migrate from ethers to viem #2705

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