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

# Execute Contract Calls

> Batch multiple contract interactions into a single user approval using send_calls and Base MCP

## What it does

`send_calls` submits a batch of raw contract calls for a single Base Account approval. Use it for DeFi interactions, multi-step operations, and NFT mints that go beyond simple send or swap.

The most common use case: [protocol plugins](/agents/plugins/native) like Moonwell prepare a `calls` array (including token approvals and deposits), and you pass it directly to `send_calls` — everything executes atomically in one approval. Moonwell works entirely via `web_request`, with no additional MCP server required.

## What you can ask

With the [Moonwell plugin](/agents/plugins/native):

```text theme={null}
Find the best USDC market on Base and supply 100 USDC
```

```text theme={null}
Borrow 500 USDC against my collateral on Moonwell
```

```text theme={null}
Repay all my Moonwell debt
```

## How it works

<Steps>
  <Step title="A plugin prepares the calls">
    Protocol plugins like Moonwell return a `calls` array, often with a chain ID from their prepare endpoints. The calls include any required token approvals and the protocol interaction itself.
  </Step>

  <Step title="Your assistant calls send_calls()">
    Passes the `calls` array and Base MCP chain name to Base MCP.
  </Step>

  <Step title="You review and approve">
    Open the approval link to review all calls in Base Account before signing.
  </Step>

  <Step title="Calls execute onchain">
    All calls in the batch execute atomically — if one fails, none go through.
  </Step>
</Steps>

## Parameters

| Parameter | Required | What it does                                                                                                  |
| --------- | -------- | ------------------------------------------------------------------------------------------------------------- |
| `chain`   | Yes      | Chain name, e.g. `base`, `base-sepolia`, `ethereum`, `optimism`, `polygon`, `arbitrum`, `bsc`, or `avalanche` |
| `calls`   | Yes      | Array of `{ to, value?, data? }` objects                                                                      |

## Related guides

<CardGroup cols={2}>
  <Card title="Native plugins" icon="puzzle-piece" href="/agents/plugins/native">
    Overview of the native plugins that prepare calls for Base MCP.
  </Card>

  <Card title="Sign messages" icon="pen-nib" href="/agents/guides/sign-messages">
    Sign individual messages and typed data.
  </Card>
</CardGroup>