
# Upgrading to InterchainJS: A Better Way to Build Cosmos Apps

We're excited to announce a major upgrade to ts-codegen! We've migrated from CosmJS to InterchainJS, bringing you a more powerful and developer-friendly experience when building Cosmos applications.

## What's Changed?

If you've been using ts-codegen to generate TypeScript clients for your Cosmos contracts, you'll notice some exciting improvements. The biggest change? We've moved away from the older CosmJS library to the newer, more robust InterchainJS.

### Out with the Old

Previously, you might have seen imports like this in your generated code:

```typescript
// The old way
import { CosmWasmClient, SigningCosmWasmClient } from '@cosmjs/cosmwasm-stargate';
```

### In with the New

Now, your generated contracts use a cleaner approach with a dedicated `baseClient.ts` file which will be the replacement for the cosmjs clients. This file will always be generated by default whether you're using `generate` or `boilerplate` commands.

If your existing code used the function or client from `contractContextBase.ts` or clients like `Factory.client.ts`, the new generatation of those files have replaced imports to use content in `baseClient.ts` properly, so you don't have to change anything.

For the usage example of baseClient, you can visit our [create-interchain-app repo](https://github.com/hyperweb-io/create-interchain-app/tree/main/examples/cosmwasm).

```typescript
// The new way
import { 
  getCosmWasmClient, 
  getSigningCosmWasmClient
} from './baseClient';
```

## Why This Matters for You

This isn't just a behind-the-scenes change – it brings real benefits to your development experience:

### Simpler Client Setup

**Before:** Setting up clients required multiple steps and async operations:

```typescript
// Old approach - more complex
const client = await CosmWasmClient.connect('https://rpc.cosmos.network');
const signingClient = await SigningCosmWasmClient.connectWithSigner(
  'https://rpc.cosmos.network',
  signer
);
```

**Now:** Much cleaner and more straightforward:

```typescript
// New approach - simpler
const client = getCosmWasmClient('https://rpc.cosmos.network');
const signingClient = getSigningCosmWasmClient(yourSigner, 'https://rpc.cosmos.network');
```

#### Automatic Gas Calculation

Now the gas fee management has been improved on the client level.
Just pass `'auto'` and let the system figure out the optimal gas fees:

```typescript
const result = await contractClient.execute(
  sender,
  { transfer: { recipient, amount } },
  'auto', // Let the system calculate gas fees
  undefined, // memo
  [], // funds
  { chain: cosmosChain } // Chain configuration
);
```

#### Custom Gas Prices When Needed

Want more control? You can still specify custom gas prices:

```typescript
const chainConfig = {
  gasPrice: {
    denom: 'uatom',
    amount: '0.025'
  }
};
```

#### Global Gas Defaults

Set default gas amounts across your entire application:

```typescript
import { setDefaultGasAmount } from './baseClient';

// Set a higher default for complex operations
setDefaultGasAmount('300000');
```

## Better Developer Experience

The migration to InterchainJS brings several developer experience improvements:

- **Better TypeScript support** with improved type safety
- **Automatic chain registry integration** for gas fee calculation
- **More flexible configuration options** for different use cases


## What You Need to Do

The good news? If you're using the latest version of ts-codegen, most of these improvements happen automatically when you regenerate your contract clients. The generated code will use the new InterchainJS-based approach out of the box.

For existing projects, you'll want to:

1. Update to the latest ts-codegen version
2. Regenerate your contract clients
3. Update any custom client code to use the new imports

## Looking Forward

This migration represents our commitment to providing the best possible developer experience for Cosmos application development. InterchainJS offers a more modern, flexible foundation that will enable even more improvements in future releases.

Ready to try it out? Check out the [Ts-Codegen documentation](https://docs.hyperweb.io/ts-codegen/developing/migration-from-cosmjs) and [InterchainJS documentation](https://github.com/hyperweb-io/interchainjs) to learn more about the underlying technology powering these improvements.

Happy coding! 🚀


Learn how to upgrade your ts-codegen project to use InterchainJS for better Cosmos app development.

TS Codegen: InterchainJS Migration