# Resources for Developers

## Developer Support Channel 

Developers are welcome to join the [Telegram channel](<https://t.me/cryptocom_agent >) for technical support.

## Cronos Networks and resources

### Explorer API keys

Explorer API keys for Cronos Chains are required to query block chain data, kindly follow the following instruction to obtain the API key for:&#x20;

{% tabs %}
{% tab title="Cronos zkEVM" %}
To get started with the Cronos zkEVM developer API, simply register an account on the [Account Registration page](https://developers.zkevm.cronos.org/register) in Cronos zkEVM developer portal, where you can access a pair of mainnet and testnet API keys on the user dashboard. You can then access the developer API service and use it to retrieve data from the available endpoints.
{% endtab %}

{% tab title="Cronos EVM" %}
Kindly follow the [instructions](https://docs.cronos.org/block-explorers/block-explorer-and-api-keys) to obtain the API key for Cronos EVM
{% endtab %}
{% endtabs %}

### Documentation

For detailed documentation of Cronos Chain, kindly visit:

* Cronos zkEVM - <https://docs-zkevm.cronos.org/>
* Cronos EVM - <https://docs.cronos.org/>

### Cronos zkEVM Mainnet URLs <a href="#cronos-zkevm-mainnet-urls" id="cronos-zkevm-mainnet-urls"></a>

* Chain ID: `388`
* Token: zkCRO ("Cronos zkEVM CRO")
* JSON RPC API (rate limited): [https://mainnet.zkevm.cronos.org](https://mainnet.zkevm.cronos.org/)
* WebSocket (rate limited): `wss://ws.zkevm.cronos.org`
* Blockchain explorer: <https://explorer.zkevm.cronos.org/>
* Gas price: ⚠️ The gas price is currently fixed at 1250 `gwei`
  * This is subject to change and is expected to be dynamic in the next major release to be announced.
* Developer portal: <https://developers.zkevm.cronos.org/>
* Contract verification interface: <https://explorer.zkevm.cronos.org/verifyContract>
* Bridge for ERC-20 tokens (Ethereum <=> Cronos zkEVM): <https://zkevm.cronos.org/bridge>

***

### Cronos zkEVM Sepolia Testnet URLs <a href="#cronos-zkevm-sepolia-testnet-urls" id="cronos-zkevm-sepolia-testnet-urls"></a>

* Chain ID: `240`
* Token: zkTCRO
* JSON RPC API (rate limited): [https://testnet.zkevm.cronos.org](https://testnet.zkevm.cronos.org/)
* WebSocket (rate limited): `wss://ws.testnet.zkevm.cronos.org`
* Blockchain explorer: <https://explorer.zkevm.cronos.org/testnet>
* Gas price: ⚠️ The gas price of is currently fixed at 1250`gwei`
  * This is subject to change and is expected to be dynamic in the next major release to be announced.
* Developer portal: <https://developers.zkevm.cronos.org/>
* Contract verification interface: <https://explorer.zkevm.cronos.org/testnet/verifyContract>
* zkTCRO faucet: <https://zkevm.cronos.org/faucet>
* [Demo project repository](https://github.com/kentimsit/cronos-zkevm-hardhat-boilerplate) for smart contract developers
* Testnet bridge for ERC-20 tokens (zkEVM testnet <=> Ethereum Sepolia): <https://zkevm.cronos.org/bridge/testnet>

***

### Cronos EVM Mainnet URLs <a href="#cronos-zkevm-sepolia-testnet-urls" id="cronos-zkevm-sepolia-testnet-urls"></a>

* Chain ID: `25`
* JSON RPC AP&#x49;**:** <https://evm.cronos.org>
* Block explore&#x72;**:** <https://explorer.cronos.org/>

***

### Cronos EVM Testnet URLs <a href="#cronos-zkevm-sepolia-testnet-urls" id="cronos-zkevm-sepolia-testnet-urls"></a>

* Chain ID: `338`
* JSON RPC API: <https://evm-t3.cronos.org/>
* Block explore&#x72;**:** <https://explorer.cronos.org/testnet>

***


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ai-agent-sdk-docs.crypto.com/resources/resources-for-developers.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.