From d4523871ce94c707ac44f68cf3aa29fd722bf67b Mon Sep 17 00:00:00 2001 From: consumeobeydie Date: Sat, 20 Jun 2026 18:28:44 +0300 Subject: [PATCH] docs: add Arc Transaction Memo integration example with Multi-Agent Orchestrator --- docs/examples/transaction-memo-integration.md | 43 +++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 docs/examples/transaction-memo-integration.md diff --git a/docs/examples/transaction-memo-integration.md b/docs/examples/transaction-memo-integration.md new file mode 100644 index 0000000..b7ed779 --- /dev/null +++ b/docs/examples/transaction-memo-integration.md @@ -0,0 +1,43 @@ +# Arc Transaction Memos: Multi-Agent Orchestrator Integration Example + +This example shows how to integrate Arc's Transaction Memos feature with an existing contract without modifying it, using the predeployed Memo contract on Arc Testnet. + +## Overview + +Transaction Memos (announced June 18, 2026) let you attach structured context to any contract call via a predeployed Memo contract, which routes the inner call through the CallFrom precompile so the original msg.sender is preserved. The Memo event is only emitted if the inner call succeeds, giving downstream systems a clean reconciliation signal. + +## Predeployed Contracts on Arc Testnet + +| Contract | Address | +|----------|---------| +| Memo | 0x5294E9927c3306DcBaDb03fe70b92e01cCede505 | +| Multicall3From | 0x522fAf9A91c41c443c66765030741e4AaCe147D0 | + +## Function Signature + +function callWithMemo(address target, bytes calldata data, bytes32 correlationId, string calldata memo) external returns (bool success, bytes memory result) + +Selector: 0xc3b2c4f8 + +This signature was derived by inspecting the Memo contract bytecode dispatcher and decoding a real on-chain transaction calldata to confirm parameter types, since the ABI was not yet published when this example was built. + +## Common Pitfalls + +- Empty revert data: behavior with cast call --from may differ from an actual sent transaction. +- Inner call must succeed: the Memo event only emits when the wrapped call succeeds. +- bytes32 correlationId must be exactly 32 bytes. + +## Live Verified Example + +Tested against the MultiAgentOrchestrator contract from arc-multi-agent: + +- Memo contract: 0x5294E9927c3306DcBaDb03fe70b92e01cCede505 +- Target: 0xe81f5BA4181eA29061C3C229c8D6EB4cFE56639C +- Tx: https://testnet.arcscan.app/tx/0x7532ce470169e2db2be43e5f9c43dd523d21e9071c04268ff5941f8ca839ef7b +- Status: Success, confirmed in 0.58 seconds + +## Resources + +- Arc Transaction Memos announcement: https://community.arc.io/home/blogs/arc-transaction-memos-structured-transaction-context-for-financial-workflows-on-arc-2026-06-18 +- Arc Contract Addresses: https://docs.arc.io/arc/references/contract-addresses +- Full implementation: https://github.com/consumeobeydie/arc-agent-api