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Smart Contract Security Audits
View Audit Services
Custom DeFi Protocol Development
Explore DeFi
Full-Stack Web3 dApp Development
View App Services
Free 30-min Web3 Consultation
Book Consultation
Smart Contract Security Audits
View Audit Services
Custom DeFi Protocol Development
Explore DeFi
Full-Stack Web3 dApp Development
View App Services
Free 30-min Web3 Consultation
Book Consultation
Smart Contract Security Audits
View Audit Services
Custom DeFi Protocol Development
Explore DeFi
Full-Stack Web3 dApp Development
View App Services
LABS
Services

Account Abstraction UserOp Simulator

We build custom simulation services for ERC-4337 UserOperations, enabling wallets and dApps to preview bundled transactions, sponsorship outcomes, and signature validation before on-chain submission.
Chainscore © 2026
overview
CORE SERVICE

Smart Contract Development

Secure, production-ready smart contracts built by Web3-native engineers.

We architect and deploy audit-ready smart contracts on EVM and Solana chains. Our code follows OpenZeppelin standards and includes comprehensive testing to prevent exploits.

  • Custom Logic: ERC-20, ERC-721, ERC-1155, DeFi protocols, DAOs, and bespoke business rules.
  • Security First: Formal verification, gas optimization, and integration with Slither & MythX.
  • Full Lifecycle: Development, deployment scripts, upgradeability patterns, and mainnet launch support.

Deliver a secure, functional MVP in 2-4 weeks, not months. We handle the complexity so you can focus on product-market fit.

key-features-cards
DEVELOPER-FIRST TOOLING

Core Capabilities of Our UserOp Simulator

Ship secure, gas-optimized smart accounts faster. Our UserOp Simulator provides the deterministic testing environment you need to validate logic, prevent exploits, and ensure seamless user experiences before mainnet deployment.

01

Deterministic Local Simulation

Test UserOperations in a sandboxed, local environment that mirrors mainnet conditions. Eliminate flaky tests and unpredictable gas costs by simulating exact bundler and paymaster behavior.

100%
Deterministic Results
0 GWEI
Local Test Cost
02

Multi-Client & Paymaster Validation

Verify compatibility across major ERC-4337 bundlers (like Stackup, Alchemy) and custom paymaster logic. Catch integration failures and sponsorship rule violations early in your dev cycle.

5+
Bundler Clients
< 5 min
Integration Test
03

Gas Estimation & Optimization

Receive precise preVerification and verification gas estimates for your UserOps. Identify and refactor inefficient patterns in your Account logic to minimize costs for end-users.

~95%
Estimation Accuracy
Up to 40%
Potential Gas Savings
04

Security & Edge Case Analysis

Automatically test for common ERC-4337 vulnerabilities like signature replay, paymaster griefing, and storage collisions. Our rule set is informed by audits of live smart accounts.

50+
Security Vectors
Audit-Ready
Output Reports
05

CI/CD Pipeline Integration

Embed simulation directly into your GitHub Actions, CircleCI, or Jenkins workflows. Automate UserOp validation on every pull request to enforce quality gates and prevent regressions.

Native
GitHub Actions
< 2 min
Pipeline Run
06

Custom Scenario Builder

Model complex, stateful user journeys—like batched transactions, social recovery flows, or session keys—to ensure your smart account behaves correctly under real-world conditions.

Unlimited
Scenario Depth
TypeScript SDK
For Automation
benefits
FROM FEATURE TO BUSINESS IMPERATIVE

Business Outcomes: Why Simulation is Non-Negotiable

UserOp simulation is not just a technical feature—it's a critical business function that directly impacts your bottom line, user trust, and operational security. Here's how our simulator delivers measurable value.

01

Eliminate Failed Transaction Costs

Pre-execute and validate every UserOp before it hits the blockchain. We prevent failed transactions and wasted gas fees, protecting your users' funds and improving their experience.

100%
Failure Prevention
$0
Wasted Gas
02

Secure Your Smart Accounts

Simulate complex multi-step operations to uncover security vulnerabilities before deployment. Our system tests against reentrancy, logic errors, and state inconsistencies specific to Account Abstraction.

Zero
Post-Deployment Exploits
24/7
Security Validation
03

Accelerate Feature Deployment

Integrate a production-ready simulator to bypass weeks of in-house development. Test new paymasters, signature schemes, and bundler logic with confidence and speed.

< 2 weeks
Integration Time
90%
Dev Time Saved
04

Ensure Paymaster Viability

Validate that your sponsored transaction logic works under real network conditions. Simulate gas price spikes and token price volatility to guarantee your subsidy model remains solvent.

100%
Sponsorship Success
Real-time
Gas Market Simulation
05

Guarantee Bundler Reliability

Test your custom bundler logic against edge cases and high-load scenarios before mainnet deployment. Ensure mempool management and operation ordering perform as expected.

99.9%
Uptime SLA
< 100ms
Simulation Latency
06

Build Unshakeable User Trust

Provide users with a seamless, predictable experience. By eliminating transaction failures and unexpected reverts, you build the reliability required for mainstream adoption.

50%+
Higher Retention
5-Star
Wallet Ratings
Infrastructure Decision Analysis

Build vs. Buy: In-House Simulation vs. Chainscore Service

A detailed comparison of the costs, risks, and time investment required to build and maintain an ERC-4337 UserOp simulation environment internally versus leveraging Chainscore's managed service.

Key FactorBuild In-HouseChainscore Service

Time to Production

6-12 months

2-4 weeks

Initial Development Cost

$150K - $300K+

$25K - $75K

Ongoing Maintenance (Annual)

$80K - $150K (2-3 engineers)

Optional SLA from $30K

Security & Audit Overhead

High (Requires dedicated audit budget)

Included (Pre-audited, battle-tested core)

Coverage (Chains & Bundlers)

Limited to initial targets

Ethereum, Polygon, Arbitrum, Base, Optimism, zkSync

Simulation Accuracy & Edge Cases

Your team's responsibility

Validated against 1M+ live UserOps

Integration Complexity

High (Manage RPCs, bundlers, paymasters)

Low (Single API, comprehensive docs)

Support & Updates

Internal team only

24/7 technical support & protocol updates

Total Cost of Ownership (Year 1)

$230K - $450K+

$55K - $105K

Strategic Recommendation

Only for teams with deep 4337 expertise and unlimited runway

For all startups and enterprises prioritizing speed, security, and cost-efficiency

how-we-deliver
PREDICTABLE, TRANSPARENT DELIVERY

Our Delivery Process: From Specification to Production

We deliver your custom UserOp Simulator through a structured, milestone-driven process designed for technical founders and CTOs. Each phase has clear deliverables and acceptance criteria, ensuring alignment and predictable outcomes.

01

Phase 1: Architecture & Specification

We conduct a technical deep-dive to define your simulator's scope, target chains (Ethereum, Polygon, Arbitrum, etc.), and required validation logic. Deliverables include a detailed technical spec and architecture diagram.

3-5 days
Spec Finalization
100%
Requirement Clarity
02

Phase 2: Core Engine Development

Our engineers build the core simulation engine in TypeScript/Go, implementing ERC-4337 Bundler RPC methods (eth_sendUserOperation, eth_estimateUserOperationGas) with support for custom paymasters and signature schemes.

1-2 weeks
Core Build
100%
Test Coverage
03

Phase 3: Integration & Custom Logic

We integrate your specific validation rules, deploy mock contracts for testing, and implement hooks for your existing wallet or dApp stack. Includes a staging environment for your team.

1 week
Integration Sprint
Staging
Environment Ready
04

Phase 4: Security Audit & Optimization

The codebase undergoes internal security review focusing on gas estimation accuracy and validation logic. We perform gas optimization and finalize comprehensive documentation.

Security
Review Complete
Full
API Documentation
05

Phase 5: Deployment & Handover

We deploy the simulator to your production infrastructure (AWS/GCP/Azure) with monitoring (Prometheus/Grafana) and provide a knowledge transfer session for your engineering team.

Production
Environment Live
Handover
Session Completed
06

Phase 6: Ongoing Support & SLA

Post-launch, we offer optional support packages with SLAs for updates, maintenance, and assistance with new ERC-4337 standards or chain integrations as they emerge.

99.9%
Uptime SLA
< 4 hours
Support Response
security-approach
CORE SERVICE

Smart Contract Development

Secure, production-ready smart contracts built for scale and compliance.

We architect, develop, and deploy custom Solidity/Rust smart contracts with a focus on security-first development. Every contract undergoes rigorous internal review and formal verification before being submitted for third-party audit.

Deliver a secure, audited, and gas-optimized contract suite in 4-6 weeks, from spec to mainnet deployment.

  • Token Systems: Custom ERC-20, ERC-721, and ERC-1155 implementations with advanced features like vesting, minting controls, and governance hooks.
  • DeFi Protocols: Automated Market Makers (AMMs), lending/borrowing pools, staking mechanisms, and yield aggregators.
  • Enterprise Logic: Multi-signature wallets, asset tokenization platforms, and custom business logic for supply chain or compliance.
Account Abstraction Simulator

Frequently Asked Questions

Get clear answers about our UserOp Simulator service, from technical details to project delivery.

Our simulator validates the complete lifecycle of a User Operation (UserOp) for ERC-4337 accounts. This includes signature verification, paymaster sponsorship logic, gas estimation, bundler compatibility, and on-chain execution. We test against edge cases like invalid nonces, insufficient funds, and custom validation rules to ensure your smart accounts behave predictably before mainnet deployment.

ENQUIRY

Get In Touch
today.

Our experts will offer a free quote and a 30min call to discuss your project.

NDA Protected
24h Response
Directly to Engineering Team
10+
Protocols Shipped
$20M+
TVL Overall
NDA Protected Directly to Engineering Team