> ## Documentation Index
> Fetch the complete documentation index at: https://ti-mm-mycompc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Request a Solana wallet signing challenge for API access

> Get a 32-byte single-use challenge to sign with your Solana wallet. First step in the credentialless auth flow that mints your API key.

The first step in claiming your API key. Instead of email + password or a signup form, you prove control of a Solana wallet: request a random 32-byte challenge here, sign it with your wallet, then POST the signature to [Claim](/api-reference/keys/claim). No account, no KYC, no leaked passwords. **Public endpoint**, no key required.

## Why agents use this

* **No email, no signup form.** Autonomous agents don't have inboxes. Wallet signature is the only auth primitive they can perform.
* **Single-use, so replay is impossible.** Each challenge is consumed the moment it's claimed.
* **Bootstraps the whole flow.** From this call to a working key: two requests and a Phantom popup.
* **Language-agnostic.** Sign with any Solana wallet SDK: web3.js, solders (Python), solana-sdk (Rust).

## Use cases

* **Phantom / Solflare popup onboarding.** Web app calls this, wallet popup asks user to sign, app POSTs to claim.
* **MCP client auto-provisioning.** Claude Desktop MCP wrapper generates a key on first use by wallet-signing the challenge.
* **Mobile wallet WalletConnect flow.** Deep link into the user's mobile wallet with the challenge, receive signature back, claim key.
* **CLI setup script.** `npx create-solana-agent` runs the challenge + claim flow and writes the key to `.env`.
* **Agent framework install.** Eliza / Rig plugin fetches challenge, signs with agent's own wallet, stores key for future calls.

## Recipe: browser-side Phantom flow

```typescript phantom-challenge.ts theme={null}
const GATEWAY = "https://solana-pulse-gateway-1021990235790.us-central1.run.app";

// 1. Get the challenge (public, no auth)
const { challenge } = await fetch(`${GATEWAY}/api/keys/challenge`).then((r) =>
  r.json(),
);

// 2. Ask the wallet to sign it
const phantom = (window as any).solana;
await phantom.connect();
const encoded = new TextEncoder().encode(challenge);
const { signature } = await phantom.signMessage(encoded, "utf8");

// 3. POST to /api/keys/claim (see next page)
console.log({ challenge, signatureBase58: signature });
```

<Tip>
  Before claiming, deposit SOL to the gateway wallet `Brpc8HoPo1d3Uiyo7kbERnjMqwLJJmbWxtwxHxzar6DU`. The claim step verifies you've paid before minting your key.
</Tip>