Parallax is a provider-agnostic pre-execution remediation and re-verification layer for onchain actions.
Parallax is a provider-agnostic pre-execution decision layer that transforms onchain transaction evidence into explainable, actionable decisions.
DeFi users already have access to quotes, transaction previews, and simulation tools. Yet understanding whether a transaction meets their expectations, why something might go wrong, and what to adjust often remains challenging.
Parallax bridges this gap by connecting execution evidence with user intent and transparent decision rules.
Built around Arbitrum Sepolia and Camelot V3, Parallax provides:
Evidence-based decisions: Interprets quotes, account state, and transaction checks to produce scope-aware outcomes: PROCEED, ADJUST, STOP, or UNKNOWN.
Actionable explanations: Identifies relevant conditions, such as insufficient balance or minimum-received requirements, and presents adjustment options.
Re-checkable workflows: Allows users to revise transaction parameters, run another check, and compare results.
Non-custodial architecture: Users retain full control. Parallax does not sign, broadcast, or execute their swaps.
Extensible infrastructure: A reusable API and TypeScript SDK provide a foundation for integrating decision checks into other applications.
On-chain Decision Attestation: Parallax has deployed a Decision Registry smart contract on Arbitrum Sepolia, enabling cryptographic commitments to completed decision records to be anchored onchain.
Through a backend-operated attestor, decision records can be independently checked against immutable onchain commitments without requiring users to sign additional transactions.
This adds a tamper-evident auditability layer while keeping transaction execution and asset custody entirely outside Parallax's control.
Deployed Contract: https://sepolia.arbiscan.io/address/0xdfc1f61e75fd551b9c309ec0bfae015adf6fe359
Our vision extends beyond a standalone swap interface. We aim to expand across more assets and DeFi protocols, embed Parallax into wallets and DEXs, and eventually support AI-agent workflows through MCP-compatible interfaces.
Rather than replacing existing DeFi tools, Parallax aims to become the decision infrastructure connecting them.
Before you sign, know what to do next.
During the buildathon, we transformed Parallax from a product concept into a functional pre-execution decision MVP integrated with Arbitrum Sepolia and Camelot V3. We implemented real ETH-to-USDC quotes, exact unsigned transaction preparation, and execution checks using Native RPC. We developed an evidence-based decision engine that produces explainable, scope-aware outcomes (PROCEED, ADJUST, STOP, or UNKNOWN), alongside a wallet-inspired interface that helps users identify issues such as insufficient balances or minimum-received mismatches, explore actionable adjustments, and re-check transactions. We also integrated supplementary Trace RPC evidence, source provenance, persistent decision records, and historical Run retrieval. To expand asset coverage, we implemented backend support for USDC-to-WETH swaps, including ERC-20 balance and allowance checks. Additionally, we built a reusable TypeScript SDK supporting quotes, transaction checks, account-state queries, Run retrieval, and re-check workflows. A major milestone was developing and deploying the Parallax Decision Registry smart contract on Arbitrum Sepolia, introducing immutable, versioned decision commitments, authorized backend attestation, idempotent anchoring, and independent verification against persisted Run records. We successfully anchored and verified a real decision commitment onchain. Deployed Contract: [https://sepolia.arbiscan.io/address/0xdfc1f61e75fd551b9c309ec0bfae015adf6fe359](https://sepolia.arbiscan.io/address/0xdfc1f61e75fd551b9c309ec0bfae015adf6fe359). Attestation Transaction: [https://sepolia.arbiscan.io/tx/0x3e40db4fdc33b8bf3b726fa7f8a60049e0518c19e6cbc98eb69c20932f374af0](https://sepolia.arbiscan.io/tx/0x3e40db4fdc33b8bf3b726fa7f8a60049e0518c19e6cbc98eb69c20932f374af0). By the end of the buildathon, Parallax had established a working foundation for turning fragmented transaction evidence into understandable, actionable decisions, with an extensible API, SDK, and onchain auditability layer supporting future integrations into wallets, DEXs, and other onchain applications.
Bootstrapped / Pre-funding Parallax is currently an early-stage, bootstrapped project developed during the Arbitrum Open House Singapore Buildathon. We have not raised external funding and are focused on validating the product, exploring ecosystem integrations, and evaluating opportunities for further development.
