> ## Documentation Index
> Fetch the complete documentation index at: https://celo-64ac69bd-palango-docs-restructure.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Challengers

> Listing of the Celo Challengers

With the [Jello Hardfork](/infra-partners/notices/archive/jello-upgrade), Celo switched to use OP Succinct Lite and introduced a set of independent challengers. Those challengers are responsible for checking the validity of the state roots sent to the L1.

## List of Challengers

Currently, there are six registered challengers. Five challengers are independent entities, one challenger is run by cLabs.

| Name                                            | Challenger address                                                                                                            |
| ----------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------- |
| [atalma.io](https://atalma.io)                  | [`0x77E831A0A6a680335BB54937E085fF625dfE3f6F`](https://eth.blockscout.com/address/0x77E831A0A6a680335BB54937E085fF625dfE3f6F) |
| [atweb3 GmbH](https://atweb3.co)                | [`0xe4ce4999b1C4C60C384AC96f370F00796ae9eC78`](https://eth.blockscout.com/address/0xe4ce4999b1C4C60C384AC96f370F00796ae9eC78) |
| cLabs                                           | [`0x7247204E46B381149d99acF88b318713fE12c32f`](https://eth.blockscout.com/address/0x7247204E46B381149d99acF88b318713fE12c32f) |
| [Grassroots Economics](https://sarafu.network/) | [`0xc6E6836CaCB6fF0a843050DB7F64bb2ab864C463`](https://eth.blockscout.com/address/0xc6E6836CaCB6fF0a843050DB7F64bb2ab864C463) |
| [Swiftstaking](https://www.swiftstaking.com/)   | [`0x53e8eeaae0731ccc888513695ec1bd792ec975ca`](https://eth.blockscout.com/address/0x53e8eeaae0731ccc888513695ec1bd792ec975ca) |
| Usopp's                                         | [`0x56966549e0953e8d6e17fcd3278b003d81f58ca8`](https://eth.blockscout.com/address/0x56966549e0953e8d6e17fcd3278b003d81f58ca8) |