> 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/call/reference/networks-and-schemes.md).

# Networks and schemes

Call supports exact-USDC buyer payments on Base and Arc; self-listing with a FeeSplitter is Base-only.

{% hint style="info" %}
Call is launching. The console does not serve Call yet; this page describes the launch flow.
{% endhint %}

Use this page to check whether a Call listing can be paid from the console or the `vapi` client. Both support Base mainnet and Arc mainnet; the public client also supports opt-in Arc Testnet.

## Payable networks in Call

Call accepts canonical USDC on these networks:

| Network      | CAIP-2 identifier | USDC notes                                                                                                                                          |
| ------------ | ----------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
| Base mainnet | `eip155:8453`     | Canonical USDC is `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`. Base uses ETH for gas.                                                              |
| Arc          | `eip155:5042`     | USDC is the predeploy at `0x3600000000000000000000000000000000000000`, with EIP-712 domain `{ name: "USDC", version: "2" }`. Arc uses USDC for gas. |

The live 402 challenge is the source of truth for the network, asset, amount, validity window, and payee. Review it before you sign.

At Call launch, the console and public client will pay exact USDC offers on Base mainnet and Arc mainnet. Self-listing with a FeeSplitter is Base-only: there is no Arc-mainnet self-listing factory. Arc buyer support does not enable Arc self-listing.

## Networks supported by `vapi`

The public client can pay exact USDC offers on Base mainnet, `eip155:8453`, and Arc mainnet, `eip155:5042`. Arc Testnet, `eip155:5042002`, is also supported when enabled. A `--network` or `--networks` option does not add another network to the client's supported set.

Enable Arc mainnet with:

```bash
vapi init --networks base,arc
vapi accounts --enable arc
```

The default public RPC is `https://rpc.mainnet.arc.io`. Set `ARC_RPC_URL` to override it. Arc sweeps keep 0.05 USDC for gas by default, and explorer links use `https://explorer.arc.io`.

## Payable scheme

Call pays `exact` offers only. The payment uses an EIP-3009 authorization for the exact amount.

Mirrored External listings can show other payment facts:

| Scheme         | How Call displays it                                                                                  | Can Call pay it? |
| -------------- | ----------------------------------------------------------------------------------------------------- | ---------------- |
| `upto`         | Shows a maximum and a `Payment` fact such as `Pay-as-you-go (upto) · needs a compatible x402 client`. | No               |
| `auth-capture` | Shows a `Payment` fact such as `Refundable (auth-capture) · needs a compatible x402 client`.          | No               |

Other schemes are dropped, including `batch-settlement`. Unknown schemes are dropped as well.

## Machine Payments Protocol

An API that answers `402` with a `WWW-Authenticate: Payment` challenge from Stripe/Tempo Machine Payments Protocol can be listed and is shown with the label **MPP (Stripe/Tempo), not payable here**. vAPI does not pay MPP, neither the console nor `vapi pay`. `vapi check` recognises it: the `transport` rule passes with the `mpp` tag, and the JSON report's `transport` field is `x402` or `mpp`.

Checked on 2026-10-02.


---

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