Example 04: Programmable Token Transfer (Default Finality + Sender Contract)

This example sends a programmable token transfer from Ethereum Sepolia to Polygon Amoy using a deployed BasicMessageSender contract:

• Data payload: "Hello, World"
• Tokens: CCIP-BnM
• Finality mode: default finality (blockConfirmations = 0)

Because this chapter uses default finality, the baseline BasicMessageReceiver is sufficient on destination. If you want the Fast Transfers (FTF) variant (blockConfirmations > 0), use Example03 with BasicMessageReceiverWithCCVs.

Scripts used:

• script/examples/Example04.s.sol:DeployBasicMessageSender
• script/examples/Example04.s.sol:Example04

What You Will Do

1. Deploy BasicMessageSender on source chain (Sepolia).
2. Ensure destination BasicMessageReceiver exists on Amoy.
3. Mint 1 CCIP-BnM on Sepolia.
4. Quote fee, fund sender contract with that exact fee amount, then send data+token.

Before You Start

Important: Keystore first

Use a local keystore account for script execution:

cast wallet import myAccount --interactive
Enter private key:
Enter password:
`myAccount` keystore was saved successfully. Address: <YOUR_EOA_ADDRESS_SHOULD_APPEAR_HERE>

This chapter assumes --account myAccount.

If you do not have a receiver deployed yet

Run:

forge script script/examples/Example04.s.sol:DeployBasicMessageReceiver \
  --rpc-url polygonAmoy \
  --account myAccount \
  --broadcast \
  --sig "run(address)" \
  <DESTINATION_ROUTER>

Save the receiver address from the [RESULT] log and use it in Step 3.

Step 1: Deploy BasicMessageSender on Sepolia

forge script script/examples/Example04.s.sol:DeployBasicMessageSender \
  --rpc-url ethereumSepolia \
  --account myAccount \
  --broadcast \
  --sig "run(address,address)" \
  <SOURCE_ROUTER> \
  <LINK_TOKEN_ON_SOURCE_CHAIN>

Save the deployed sender address from the [RESULT] log.

Step 2: Get 1 CCIP-BnM Token on Sepolia

Use the registered Sepolia token from Example 01:

forge script script/Faucet.s.sol:Faucet \
  --rpc-url ethereumSepolia \
  --account myAccount \
  --broadcast \
  --sig "run(address)" \
  <CCIP_BNM_SOURCE_TOKEN_ADDRESS>

Step 3: Send Hello World + CCIP-BnM Through Sender Contract

forge script script/examples/Example04.s.sol:Example04 \
  --rpc-url ethereumSepolia \
  --account myAccount \
  --broadcast \
  --sig "run(address,address,uint64,address,string,address,uint256,uint32)" \
  <DEPLOYED_BASIC_MESSAGE_SENDER_ADDRESS> \
  <SOURCE_ROUTER> \
  <DESTINATION_CHAIN_SELECTOR> \
  <DEPLOYED_BASIC_MESSAGE_RECEIVER_ADDRESS> \
  "Hello, World" \
  <CCIP_BNM_SOURCE_TOKEN_ADDRESS> \
  <AMOUNT> \
  <GAS_LIMIT>

Parameter notes:

• This example always uses default finality by setting blockConfirmations = 0 in the script.
• <AMOUNT> uses token decimals (1e18 is 1 token for 18-decimal tokens).
• <GAS_LIMIT> must be > 0 because the receiver contract callback handles data.
• The script first quotes the fee, then funds sender contract with that exact amount before calling send.
• If fee conditions change between quote and send, rerun the script to re-quote and retry.

Verify Result

Example04 logs a CCIP message ID. Track it in the CCIP Explorer:

• https://ccip.chain.link

Optional receiver checks on Amoy:

cast call <DEPLOYED_BASIC_MESSAGE_RECEIVER_ADDRESS> "latestMessage()(bytes)" --rpc-url polygonAmoy
cast call <DEPLOYED_BASIC_MESSAGE_RECEIVER_ADDRESS> "latestSender()(address)" --rpc-url polygonAmoy
cast call <DEPLOYED_BASIC_MESSAGE_RECEIVER_ADDRESS> "latestSourceChainSelector()(uint64)" --rpc-url polygonAmoy