[Final Report] zkArb SDK — Dev Tooling on One and Stylus (D.A.O. Season 3)

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[Final Report] zkArb SDK — Dev Tooling on One and Stylus (D.A.O. Season 3)

Hi everyone, this is the final report for zkArb SDK, funded through the Arbitrum D.A.O. Grant Program Season 3, Dev Tooling on One and Stylus domain. All seven milestones have been delivered.

Summary

zkArb SDK is a zero-setup toolkit that turns the full zero-knowledge proof lifecycle on Arbitrum into a few CLI commands and one JavaScript function. A developer goes from a Circom circuit to a deployed on-chain verifier and a working proof check, with no manual snarkjs, ABI or calldata work. The goal was to let frontend and full-stack developers, not only cryptography specialists, ship privacy-preserving features on Arbitrum.
Grantee HackTour India
Project lead Jatin Sahijwani
Grant $13,000 across 7 milestones
Approved 24 Sep 2025
Proposal Questbook
Repository github.com/jatinsahijwani/zkArb-sdk (MIT)
Docs jatinsahijwani.github.io/zkArb-sdk
Playground zkarb.dev
Full report Google Doc

At a glance

  • 7 / 7 milestones delivered
  • 57 GitHub stars, 3 forks, 46 commits
  • 2 npm packages: zkarb-sdk and create-zkarb-app
  • 3 real ecosystem integrations: Savique, TempWallets, rekt_ceo
  • 10+ external developer contributions across the integrations
  • 120+ members in the Telegram support community
  • 3 published pilot-developer case studies

Milestones

# Milestone Funding (USD) Delivered Evidence
1 Core ZK SDK architecture and foundation 4,500 21 Oct 2025 demo
2 Arbitrum deployment and proof verification 2,550 18 Nov 2025 demo
3 Orbit research and prototyping 800 19 Dec 2025 demo, branch
4 Templates, examples and developer docs 1,000 4 Jan 2026 create-zkarb-app, docs
5 Community engagement and adoption 1,500 26 Feb 2026 university workshops, 3 pilot developers
6 Real project integration 700 7 Jul 2026 3 integrations (below)
7 Final report 1,950 7 Jul 2026 this report

What the SDK does

Command What it does
zkarb-sdk compile <circuit> Compiles the Circom circuit and runs the Groth16 setup; outputs r1cs, wasm, zkey and verifier.sol
zkarb-sdk test <folder> <input.json> Generates a proof locally; outputs proof.json and public.json
zkarb-sdk deploy <folder> <key> [flags] Deploys the verifier. Flags: --network one|nova|sepolia|orbit, --rpc for any Orbit chain, --optimized for smaller calldata, --bridge-l1 for L1 messaging
verifyProof(input, folder) Generates a proof and verifies it on-chain; returns true/false
verifyAndEmit(input, folder, key) Verifies on Arbitrum and relays the result to Ethereum L1 via native messaging

The SDK is modular (compiler, prover, verifier, deployment and verification modules). The CLI is a thin wrapper over the same functions the JS API exposes, so teams can use the whole pipeline or just one part. CI runs on GitHub Actions with a Jest test suite.

Milestone 6: real project integrations

All three integrations live in public repositories, with pull requests from developers outside our team.

  • Savique, zero-knowledge proof of savings (Arbitrum Sepolia). Users prove “I have saved at least X for at least Y days” without revealing their wallet, balance or history. A server route reads the on-chain vault balance and calls verifyProof() as a read-only call: no transaction, no gas. Third parties get a shareable link with a verified badge. If savings are below the threshold, a valid proof can’t be produced. App · Code
  • TempWallets, zero-knowledge rate limiting. Users prove they’re within a usage limit without exposing the identifiers behind it. PR #73 was merged into main by the maintainer on 6 Mar 2026. App
  • rekt_ceo, community NFT platform. A dedicated zk-integration module, contributed by five outside developers in PRs #14–#18. App · Code

Together they cover private proof of funds, privacy-preserving usage control, and ZK verification inside a consumer app.

Learnings

  1. Abstraction drives adoption. Integrators succeeded because they never had to touch snarkjs, calldata or verifier ABIs.
  2. Real integrations are the best usability test. Savique showed the SDK holding up in a genuine privacy use case, with a clean read-only verification path.
  3. Standard outputs and a hosted playground cut time-to-first-proof, which was the project’s core promise.

What’s next

  • Deeper Orbit chain integrations, building on the Milestone 3 research
  • A larger template library for common privacy patterns
  • Composable input handling for proof aggregation across protocols
  • Continued community programs through HackTour India

The repository, docs, playground and community channels stay live.

Team

  • Jatin Sahijwani (GitHub): project lead; core SDK, circuits and contracts
  • Anirudh Singh Chouhan (GitHub): frontend integration, docs and example apps

Links

Thanks to the D.A.O. team and the Arbitrum community for supporting this work.