> ## Documentation Index
> Fetch the complete documentation index at: https://docs.biconomy.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Testnet Sponsorship

> Gas sponsorship works out-of-the-box on testnets — no dashboard setup needed

On testnets you can try sponsorship **without a dashboard API key**. Use the staging MEE environment and Biconomy's shared testnet gas tank. No dashboard configuration, no API key with sponsorship enabled, and no billing setup required.

<Info>
  For general testnet setup (staging node URL, supported chains, limitations), see [Working with Testnets](/overview/abstractjs/working-with-testnets).
</Info>

## Testnet setup (no API key)

Use the SDK helpers `getDefaultMEENetworkUrl` and `getDefaultMEENetworkApiKey` with `true` to point to the staging environment where all supported testnets are available:

```typescript theme={null}
import {
  createMeeClient,
  getDefaultMEENetworkUrl,
  getDefaultMEENetworkApiKey,
  getDefaultMeeGasTank,
  toMultichainNexusAccount,
  getMEEVersion,
  MEEVersion
} from "@biconomy/abstractjs";
import { http } from "viem";
import { baseSepolia } from "viem/chains";

const account = await toMultichainNexusAccount({
  signer,
  chainConfigurations: [
    { chain: baseSepolia, transport: http(), version: getMEEVersion(MEEVersion.V2_1_0) }
  ]
});

const meeClient = await createMeeClient({
  account,
  url: getDefaultMEENetworkUrl(true),
  apiKey: getDefaultMEENetworkApiKey(true)
});
```

## Execute sponsored supertransaction on testnet

When executing, pass `sponsorship: true` and use the same staging URL and shared gas tank via `sponsorshipOptions`:

```typescript theme={null}
const result = await meeClient.execute({
  instructions: [dummyInstruction],
  sponsorship: true,
  sponsorshipOptions: {
    url: getDefaultMEENetworkUrl(true),
    gasTank: getDefaultMeeGasTank(true)
  },
});
```

`getDefaultMeeGasTank(true)` returns the testnet sponsorship gas tank used by the staging environment.

## Active testnets (staging)

The following testnet chains support sponsored transactions on staging:

| Chain                  | Chain ID |
| ---------------------- | -------- |
| Arc Testnet            | 5042002  |
| Avalanche Fuji Testnet | 43113    |
| Base Sepolia           | 84532    |
| Chiliz Spicy Testnet   | 88882    |
| Fluent Testnet         | 20994    |
| Mocaverse Testnet      | 222888   |
| OP Sepolia             | 11155420 |
| Plasma Testnet         | 9746     |
| Sei Testnet            | 1328     |
| Sepolia                | 11155111 |
| Sonic Testnet          | 14601    |
| World Chain Sepolia    | 4801     |

## Quickstart repos

You can run sponsorship on testnets with zero config using these quickstarts. Clone, install, and run—no API keys or private keys required:

* **[Chiliz Spicy Testnet](https://github.com/bcnmy/chiliz-spicy-quickstart)** — `git clone https://github.com/bcnmy/chiliz-spicy-quickstart.git` then `bun i` and `bun run index.ts`

This example uses Nexus smart account and MEE supertransaction sponsorship (gasless) on staging.

## Moving to production

When you're ready for mainnet, sponsorship **does** require dashboard setup. See [Sponsor Gas](/gasless-apps/sponsorship#setup) for the full production configuration steps.