Cross-Chain Donations Research for GitCoin Grants

Objective

GitCoin Grants wanted a smoother, more reliable UX for cross-chain donations-while staying true to the project’s values of low fees, low trust, and multi-chain openness.

Raid Guild (with contributions from 0xSero) was tasked with researching and testing bridging options to support AlloV2 chains and real donor behavior.

Project Constraints

From conversations with stakeholders, the constraints were clear:

1. Cost-Effective – Donation flows must remain accessible to small donors.
2. Trust-Minimized – Avoid centralized, opaque trust assumptions wherever possible.
3. Multi-Chain Compatible – Support all AlloV2 chains (except PGN).
4. Native + Stablecoins – Prioritize common, liquid tokens.
5. Transparent – Preserve the ability to track donor information (e.g. msg.sender).

Process

Phase 1 – Research

The team evaluated multiple bridging options against the constraints.

Considered:

• Connext
• Li.Fi
• Decent

Excluded:

• CCIP – limited chain coverage.
• LayerZero – bridging only, no liquidity layer.
• Stargate – only via Li.Fi wrappers.

Insight: Every option had trade‑offs. Connext, for instance, lacked Fantom support, which mattered for some AlloV2 deployments.

Phase 2 – Testing

Research moved quickly into hands-on testing with simulated and real‑world scenarios.

1. Mock Contracts

   • A CrossChainAdapterContract and MockAllo were deployed to Arbitrum, Polygon, and Optimism.
   • These mimicked the core donation flow.

2. Simulation Tools

   • Tenderly Forks to replicate chain environments and make tests reproducible.
   • CLI scripts to automate bridge API calls with fixed transaction data.
   • Google Sheets to log and compare results.

3. Real Data

   • Test data from a real grants round was used to reflect actual donor patterns.

Findings

Solution Comparison

Cost Analysis

Observations:

• Connext offered lowest simulated costs and very debuggable, contract-centric integrations.
• Li.Fi provided excellent chain coverage and strong routing but slightly higher costs.
• Decent’s tooling and documentation were not yet mature enough for production in this timeframe.

Challenges

1. Chain-Specific Quirks – For example, intermittent failures on Arbitrum via Li.Fi despite identical configs.
2. Automation Gaps – Not all bridge APIs were equally automation‑friendly under the tight deadline.
3. Cost vs. Trust – Batch bridging reduced costs but introduced additional trust assumptions.

Proposed Architectures

1. Per-Donation Bridging

• Each donation is bridged individually.
• Pros: Best for decentralization and transparency.
• Cons: Higher per‑tx costs.

2. Batch Bridging

• Donations aggregate into a multi-sig and bridge periodically.
• Pros: Lower fees, potential operational efficiency.
• Cons: More trust, more operational complexity.

Recommendations

Short-Term

• Connext

  • Great candidate for an initial implementation: low cost, mature stack, and simple debugging.
  • Option to run a custom router for fee capture.

• Li.Fi

  • Strong choice for projects that value broad chain support, flexible routing, and insurance.

Long-Term

• Explore xERC20 patterns for more native, low-slippage cross-chain assets.
• Track the evolution of Decent as its ecosystem matures.

Learnings & Next Steps

1. API Quality Matters – Connext’s mature tooling accelerated implementation; gaps slowed others down.
2. L2s Are the Sweet Spot – More predictable costs and speeds on L2s reinforced focusing there.
3. Testing Depth – Future work should expand datasets and refine automation to surface subtler behaviors.

Next steps proposed to GitCoin Grants:

• Decide on an initial bridge partner (likely Connext or Li.Fi).
• Build a more exhaustive, automated evaluation harness for future comparisons.
• Publish findings to help the broader grants/donations ecosystem.

This case study shows the kind of pragmatic, research-heavy engineering work that 0xSero brings: deep comparison of options, realistic testing, and clear trade-off analysis rather than chasing hype.

For more code, experiments, and production work around bridges, infra, and agents, see 0xSero on GitHub at https://github.com/0xSero and the Sybil Solutions repo at https://github.com/0xSero.