Arbitrary Messaging: Canton as Destination

This tutorial demonstrates how to send arbitrary data from Ethereum Sepolia to Canton and execute the message on Canton using the ccip-starter-kit-canton.

Introduction

When Canton is the destination chain, the source send happens on Ethereum Sepolia and execution happens on Canton. For data-only messages:

  1. You call the CCIP Router on Sepolia via any2canton:data.
  2. CommitteeVerifier operators validate and aggregate proofs.
  3. You run any2canton:manual-exec to execute on Canton — the SDK finds or creates a compatible CCIPReceiver.

What You Will Build

In this tutorial, you will:

  • Send a data-only message from Sepolia to your Canton party with any2canton:data.
  • Wait for source finality and Committee Verifier proofs on the indexer.
  • Execute the message on Canton with any2canton:manual-exec.
  • Track progress in the CCIP Explorer.

Understanding Arbitrary Messaging (any2canton)

Key points when Canton is the destination:

  • Two-step flow: Send on Sepolia, then manually execute on Canton (all any2canton tutorials use manual execution on Canton).
  • Receiver: Defaults to the party in canton-config.json. Override with --cantonReceiver on send or --receiver on manual exec.
  • Finality: Default --finality finalized waits for Sepolia finality before execution is allowed. Pass --finality 32 (or another block depth) for faster-than-finality.
  • Fee payment: CCIP fees on Sepolia default to native ETH. Pass --feeToken link to pay in LINK.

See the Canton as Destination flow in the overview.

How the Scripts Work

scripts/any2canton/ccipSendData.ts:

  1. Resolves the Canton receiver party from canton-config.json.
  2. Builds and sends a data-only CCIP message via the SDK's sendMessage on Sepolia.
  3. Prints the CCIP Message ID and a copy-pasteable any2canton:manual-exec command.

scripts/any2canton/manualExecute.ts:

  1. Looks up the message using the Sepolia source transaction hash from the send output.
  2. Fetches proofs from the indexer and disclosures from Global CCIP EDS.
  3. Calls CantonChain.execute — the SDK resolves or creates the CCIPReceiver and submits to the ledger.

Running the Tutorial

Prerequisites Check

  1. Complete prerequisites.

  2. Confirm Sepolia ETH balance:

    Terminal
    npm run check-balance -- --chain sepolia --token link

Step 1: Send from Sepolia

Terminal
npm run any2canton:data -- --dataString "Hello Canton"

Pay fee in LINK:

Terminal
npm run any2canton:data -- --dataString "Hello Canton" --feeToken link

Request faster execution with block-depth finality (32 confirmations):

Terminal
npm run any2canton:data -- --dataString "Hello Canton" --finality 32

Override the Canton receiver party:

Terminal
npm run any2canton:data -- --dataString "Hello Canton" --cantonReceiver 'yourParty::1220…'

Expected send output

📧 Sending data from Sepolia → Canton: "Hello Canton"
   Receiver party: yourParty::1220…
🆔 CCIP Message ID: 0x…
🔗 CCIP Explorer: https://ccip.chain.link/#/side-drawer/msg/0x…
📜 Source transaction: https://sepolia.etherscan.io/tx/0x…

⚙️  Execute on Canton once the message is finalized on Sepolia:
   npm run any2canton:manual-exec -- 0x<messageId>

Save the CCIP Message ID (🆔 CCIP Message ID) — or the Sepolia source transaction hash (📜 Source transaction) — from the send output for the execution step. any2canton:manual-exec accepts either.

Step 2: Execute on Canton

Wait until the message is ready — timing depends on --finality:

  • finalized (default): Wait for Sepolia finality (often 15+ minutes).
  • Block depth (e.g. 32): Wait for the specified number of Sepolia confirmations.

Monitor status in the CCIP Explorer. When proofs are on the indexer, run:

Terminal
npm run any2canton:manual-exec -- <sepoliaTxHash | messageId>

You can pass either the Sepolia source transaction hash or the CCIP Message ID (0x…). They share the same 0x+64-hex shape, so the script resolves the message from whichever matches. Examples:

Terminal
# By Sepolia source transaction hash
npm run any2canton:manual-exec -- 0x5a814d64666f60d2777c5425e8d0ea5a4b1bc9a3215eaeabced8b248050a3b99

# By CCIP Message ID
npm run any2canton:manual-exec -- 0x1220e4133ede8f2daf2e665b53321da54d1bd0b8e00fb1cece20b63079c1d48d6a5b

Expected execution output

⚙️  Executing on Canton (OffRamp 0x…)…
   Resolving CCIPReceiver, fetching EDS disclosures, and submitting to the ledger — often 1–3 minutes with no further output.
✅ Canton execution transaction: https://lighthouse.testnet.cantonloop.com/transactions/…

Verification

  1. Confirm SUCCESS in the CCIP Explorer.
  2. Inspect the Canton execution transaction on Canton Lighthouse.

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