> For the complete documentation index, see [llms.txt](https://docs.vapinetwork.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vapinetwork.ai/for-agents/buyer-local-wallet.md).

# The buyer-local wallet

The buyer-local wallet (@vapi/mcp, runs on Agent Cash) is a local MCP server and CLI. It gives Claude, Cursor, and other MCP clients a small USDC wallet that signs x402 payments on your machine. It does not require a vAPI account or API key.

**Custody, in one paragraph**

The private key is generated locally and stored in an encrypted keystore (scrypt, N=2^15, AES-256-GCM), by default in `~/.vapi/agent-cash`. Each payment is an exact EIP-3009 authorization for a specific amount, recipient, token, chain, nonce, and validity window. The vendor receives the authorization, never the key. vAPI receives neither. Losing both the keystore and its backup, or the passphrase, permanently loses the wallet's funds.

## Tools

| Tool     | What it does                                                                                                                                                                              |
| -------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `search` | Finds APIs, service offers, and public open tasks. API results are callable; offers and tasks include their web action. Parameters: `query?`, `kinds?`, `network?`, `limit?`, `cursor?`   |
| `call`   | Calls an endpoint and pays only if it returns a supported x402 exact challenge. Non-402 responses come back unpaid. Use an `id` from `search` in the current process, or an explicit URL. |
| `wallet` | Returns the address and USDC balance per configured network.                                                                                                                              |

The wallet does not act on service offers or open tasks; those continue in vAPI Tasks.

**Safety rails**

The call tool requires HTTPS and blocks private, loopback, and link-local destinations by default (`allowPrivateNetwork` bypasses this deliberately and completely). Plain HTTP is limited to localhost, and a signed payment never travels over HTTP.

## Networks

| Network      | CAIP-2         | USDC                                         | Gas  | Notes                                     |
| ------------ | -------------- | -------------------------------------------- | ---- | ----------------------------------------- |
| Base mainnet | eip155:8453    | `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` | ETH  | Default. RPC defaults to mainnet.base.org |
| Arc testnet  | eip155:5042002 | `0x3600000000000000000000000000000000000000` | USDC | Opt-in via `ARC_TESTNET_RPC_URL`          |

**Sweep back**

`balance` shows holdings; `sweep-back 0xYourWallet` returns funds. Base sweeps the full USDC balance (gas is ETH). Arc testnet keeps 0.05 USDC as gas headroom by default (`VAPI_ARC_GAS_HEADROOM_USDC` adjusts it).


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