> ## Documentation Index
> Fetch the complete documentation index at: https://docs.0xarchive.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Auth & keys endpoints

> Sign in existing wallets, manage API keys, start paid x402 access, revoke keys, and inspect the retired Free wallet-signup compatibility route.

Choose a route below. Each page includes parameters, auth, responses, and examples.

| Endpoint                                                                                                                              | Method | Path                    | Group               |
| ------------------------------------------------------------------------------------------------------------------------------------- | ------ | ----------------------- | ------------------- |
| [Get SIWE challenge message](/api-reference/web3-authentication/get-siwe-challenge-message)                                           | POST   | /v1/auth/web3/challenge | Web3 Authentication |
| [List API keys for wallet](/api-reference/web3-authentication/list-api-keys-for-wallet)                                               | POST   | /v1/web3/keys           | Web3 Authentication |
| [Revoke an API key](/api-reference/web3-authentication/revoke-an-api-key)                                                             | POST   | /v1/web3/keys/revoke    | Web3 Authentication |
| [Start Build or Pro access via x402 USDC payment](/api-reference/web3-authentication/start-build-or-pro-access-via-x402-usdc-payment) | POST   | /v1/web3/subscribe      | Web3 Authentication |
| [Verify SIWE signature](/api-reference/web3-authentication/verify-siwe-signature)                                                     | POST   | /v1/auth/web3/verify    | Web3 Authentication |
| [Wallet free signup retired](/api-reference/web3-authentication/create-free-tier-account-and-api-key)                                 | POST   | /v1/web3/signup         | Web3 Authentication |