Introduction

Smart Contract & Chaincode Templates (EVM & Fabric)

• EVM-compatible networks using Solidity (e.g., Ethereum, Besu, Quorum Polygon, Avalanche)
• Hyperledger Fabric networks using GoLang and TypeScript

These templates are crafted for developers looking to accelerate smart contract or chaincode development, ensure security alignment, and streamline integration with middleware, APIs, and off-chain systems.

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What Are These Templates?

These are starter libraries built with industry-relevant design patterns and reusable code components. Each one includes:

EVM Templates (Solidity + TypeScript)

• Core Solidity contracts structured for modular deployment
• Built-in patterns like Ownable, role-based access control, and event logging
• TypeScript SDK bindings for contract interaction and deployment

Fabric Templates (GoLang + TypeScript)

• GoLang-based chaincode modules for key-value data storage, access control, and function invocation
• Transaction flow patterns using Fabric Contract API
• TypeScript client SDKs for ledger access, endorsement submission, and result handling

Each template is intended to work as a scaffold, allowing developers to focus on domain logic, not base plumbing.

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What Do These Templates Help With?

By using these templates, you will:

• Avoid writing redundant boilerplate for state reads/writes, ACLs, and access layers
• Kick-start full-stack blockchain workflows with backend, smart contracts, and integration layers
• Implement clean separation of concerns between business logic and system orchestration
• Follow best practices for security, gas/resource efficiency, and observability
• Accelerate delivery of POCs, MVPs, or production-grade logic

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SettleMint's smart contract templates serve as open-source, ready-to-use foundations for blockchain application development, significantly accelerating the deployment process. These templates enable users to quickly customize and extend their blockchain applications, leveraging tested and community-enhanced frameworks to reduce development time and accelerate market entry.

Open-source smart contract templates under the MIT license

Benefit from the expertise of the blockchain community and trust in the reliability of your smart contracts. These templates are vetted and used by major enterprises and institutions, ensuring enhanced security and confidence in your deployments.

Template library

The programming languages for smart contracts differ depending on the protocol:

• For EVM-compatible networks (like Ethereum), smart contracts are written in Solidity.
• For Hyperledger Fabric, smart contracts (also called chaincode) are written in TypeScript or Go.

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Solidity contracts IDE

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Chaincode templates (hyperledger fabric)

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Important Notes Before Usage

Key cautions:

• Security: Templates should be audited for your use case and environment specifics. Critical paths like funds transfer or permission control must be reviewed manually and/or formally verified.
• Customization Required: The templates are generic. Specific business logic, regulatory constraints, and contract-specific behaviors must be implemented manually.
• Resource Considerations: Smart contract templates must be gas-efficient (EVM), and Fabric templates must avoid long execution or response times due to chaincode lifecycle constraints.
• Environment Sensitivity: Test on devnets (e.g., Ganache, local Fabric) before deploying on public/mainnet infrastructure.

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Best Practices for Template Adoption

1. Separate Core Logic and Permissions

• Define role-based modifiers (Solidity) or access logic (GoLang) as reusable layers
• Avoid embedded ACLs in core business functions to maintain clarity and auditability

2. Follow Transactional Boundaries

• In Fabric: Avoid multiple read/write invocations inside a loop unless atomicity is ensured
• In EVM: Minimize state changes per call to avoid unnecessary gas consumption or complexity

3. Structure Events Consistently

• Use semantic, structured event naming (ProfileCreated, AssetTransferred)
• Emit key identifiers and indexes for off-chain sync and indexing systems (e.g., The Graph, Kafka listeners)

4. Leverage Strong Typing in TypeScript SDKs

• Use typed interfaces for contract interaction and payload schemas
• Ensure runtime error handling for all transaction submission flows and network responses

5. Use Version Control for Models

• Store contract/chaincode hashes and deployment metadata
• Implement migration logic for versioned schema changes in smart contracts or ledger records

6. Align With CI/CD and Test Frameworks

• Add unit and integration tests with frameworks like Mocha, Chai, Jest (for TS), and Go test (for Fabric)
• Include basic gas profiling or peer endorsement simulations
• Use GitHub Actions, GitLab CI, or similar for continuous checks

7. Adopt Secure Development Patterns

• Avoid dynamic delegatecall or unbounded loops in Solidity
• Use Fabric's built-in MSP identity abstraction for managing user roles
• Sanitize and validate all inputs rigorously, both on-chain and at the API level

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Languages & Tooling Used

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What's Next?

You can now browse specific templates in:

• EVM Contracts (Solidity)
• Fabric Chaincode (GoLang + TypeScript)

The smart contract and chaincode libraries aim to help developers and teams:

• Move from zero to working logic quickly
• Avoid reinventing core state and ACL patterns
• Align with best practices across Solidity, GoLang, and TypeScript
• Establish a common starting point for internal or client-facing solutions

Use them as a launchpad, not an endpoint , always customize to your environment, test with realistic data, and plan for maintainability and audit readiness.