💭Understanding the cheqd SDK

This guide provides a clear understanding of the cheqd SDK's architecture, modules, and practical use cases to help you choose the right tools for your decentralized identity solutions.

SDK Architecture Overview

The cheqd SDK is built around four core modules that work together to provide comprehensive identity management and transaction processing capabilities:

Module Overview & Use Cases

🆔 DID Module

Purpose: Complete lifecycle management for Decentralized Identifiers

Key Features:

• Create, update, and deactivate DIDs

• Support for multiple verification methods (Ed25519, secp256k1, RSA)

• Key rotation and authentication management

• Integration with fee abstraction and dynamic pricing

When to Use:

• Building identity wallets or credential platforms

• Creating enterprise identity systems

• Developing SSI (Self-Sovereign Identity) applications

• Managing organizational identities

Practical Use Cases:

• Digital Identity Wallets: Create DIDs for users with multiple authentication methods → See DID Creation Guide

• Enterprise Identity: Manage corporate identities with key rotation capabilities → See DID Management

• Multi-Signature Operations: Set up DIDs with multiple controllers for organizational use → See Multi-Controller Setup

📁 Resource Module

Purpose: Create and manage DID-Linked Resources (schemas, credential definitions, revocation lists)

Key Features:

• Store schemas, credential definitions, and revocation registries

• Version control and resource linking

• Flexible media type support (JSON, images, documents)

• Resource collection management

When to Use:

• Building credential issuance platforms

• Creating verifiable credential ecosystems

• Managing schema registries

• Storing credential-related metadata

Practical Use Cases:

• Credential Schema Management: Store and version credential schemas for issuers → See Resource Creation

• Revocation Lists: Manage credential revocation registries → See Status Lists

• Trust Registry Data: Store trusted issuer lists and governance documents → See Trust Registries

💱 Fee Abstraction Module

Purpose: Pay transaction fees using alternative IBC tokens instead of native CHEQ

Key Features:

• Support for USDC, EURe, OSMO, and other IBC tokens

• Automatic rate conversion and fee calculation

• Cross-chain fee payment capabilities

• Integration with all identity operations

When to Use:

• Applications requiring stable fee costs

• Cross-chain identity solutions

• Enterprise applications with specific token preferences

• Users wanting to avoid native token volatility

Practical Use Cases:

• Stablecoin Fee Strategy: Pay fees in USDC for predictable costs → See USDC Integration

• Cross-Chain Applications: Accept fees in tokens from connected Cosmos chains → See IBC Token Usage

• Enterprise Fee Management: Use EUR-backed tokens for regulatory compliance → See EURe Integration

📈 Feemarket Module

Purpose: Dynamic fee calculation based on network congestion for Cosmos SDK transactions

Key Features:

• Real-time gas price adjustment

• Network congestion-based pricing

• Automatic fee optimization

• Standard Cosmos SDK transaction support

When to Use:

• Applications requiring cost optimization

• High-throughput transaction processing

• Standard Cosmos SDK operations (transfers, staking)

• Network efficiency optimization

Practical Use Cases:

• Cost Optimization: Automatically adjust fees based on network conditions → See Dynamic Pricing

• High-Volume Operations: Process many transactions efficiently → See Fee Optimization

• Network Management: Monitor and respond to congestion → See Real-Time Pricing

Integration Patterns

Module Combinations for Common Scenarios

🏢 Enterprise Identity Platform

Modules: DID + Resource + Fee Abstraction Use Case: Corporate identity management with stable costs

// Create enterprise DID with USDC fees
const enterpriseDID = await didModule.createDidDocTx(signInputs, payload, feePayer, usdcFee);

// Store governance documents as resources
const governanceDoc = await resourceModule.createLinkedResourceTx(resourceInputs, payload, feePayer, usdcFee);

🎓 Educational Credential System

Modules: DID + Resource + Fee Abstraction Use Case: University credential issuance with predictable fee costs

// Create institution DID
const universityDID = await didModule.createDidDocTx(/* institution setup */);

// Create credential schema as resource
const degreeSchema = await resourceModule.createLinkedResourceTx(/* schema setup */);

💳 High-Volume Transaction Processing

Modules: DID + Feemarket Use Case: Efficient transaction processing with dynamic pricing

// Get optimal gas price from feemarket
const gasPrice = await feemarketModule.getGasPrice();

// Process transactions with optimized fees
const result = await signer.signAndBroadcast(address, messages, gasPrice);

🌐 Cross-Chain Identity Bridge

Modules: All Modules Use Case: Multi-chain identity with flexible fee payment

// Support both fee abstraction and dynamic pricing
const feeStrategy = networkCongestion > threshold ? 
  await feemarketModule.calculateOptimalFee() : 
  await feeAbstractionModule.convertToPreferredToken(baseFee);

Advanced Capabilities

🔧 Gas Simulation & Transaction Optimization

For production applications requiring precise cost control and reliable execution:

Key Features:

• Pre-transaction gas estimation

• Smart transaction batching

• Built-in retry mechanisms with exponential backoff

• Circuit breaker patterns for resilience

When to Use:

• Production applications with SLA requirements

• High-value transactions requiring certainty

• Batch processing operations

• Cost-sensitive applications

Learn More: Gas Simulation & Optimization Guide

Quick Decision Matrix

Use this matrix to quickly identify which modules you need:

Your Requirement	Recommended Modules	Key Use Cases
Basic Identity Management	DID Module	User accounts, authentication
Credential Issuance	DID + Resource	Schemas, credential definitions
Stable Fee Costs	Any Module + Fee Abstraction	Enterprise apps, predictable budgets
Cost Optimization	Any Module + Feemarket	High-volume apps, efficiency focus
Cross-Chain Identity	DID + Resource + Fee Abstraction	Multi-chain applications
Production Reliability	All Modules + Gas Simulation	Mission-critical applications

Getting Started

1. Start Here: SDK Setup Guide - Install and configure the SDK

2. Choose Your Path:

   • Identity First: Begin with DID Module

   • Cost Control: Start with Fee Abstraction

   • Optimization: Explore Gas Simulation

3. Advanced Integration: Combine modules based on your specific requirements

Module Documentation

• DID Module - Complete DID lifecycle management

• Resource Module - DID-Linked Resource operations

• Fee Abstraction Module - Multi-token fee payments

• Feemarket Module - Dynamic fee optimization

• Gas Simulation Guide - Advanced transaction optimization

Each module includes comprehensive examples, error handling patterns, and production best practices to help you build robust decentralized identity solutions.