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 EIP-5792 contract calls to your Base Account in a single 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 like Morpho prepare a calls array (including token approvals and deposits), and you pass it directly to send_calls — everything executes atomically in one approval.

What you can ask

With the Morpho plugin installed:

Find the best USDC vault on Base and deposit 100 USDC

Supply 1 ETH as collateral on Morpho and borrow 2000 USDC

Repay all my Morpho debt

How it works

1. A plugin prepares the calls

   Protocol plugins like Morpho return a calls array and chainId from their prepare_* tools. The calls include any required token approvals and the protocol interaction itself.

2. Your assistant calls send_calls()

   Passes the calls array and hex chainId to Base MCP.

3. You review and approve

   Open the keys.coinbase.com link to review all calls in the batch before signing.

4. Calls execute onchain

   All calls in the batch execute atomically — if one fails, none go through.

Parameters

Parameter	Required	What it does
chainId	Yes	Hex chain ID: 0x2105 for Base mainnet, 0x14a34 for Base Sepolia
calls	Yes	Array of { to, value?, data? } objects

Related guides

Morpho plugin

Full Morpho orchestration pattern — query, prepare, execute.

Sign messages

Sign individual messages and typed data.