Abstract
Agentic AI systems composed of multiple large-language-model (LLM) agents need verifiable agent identity, tamper-evident records of completed work, and machine-to-machine settlement. Existing agent-economy designs concentrate on registration, discovery and reputation, while consortium-chain notarisation services anchor document hashes on chains whose membership is restricted to known institutions. We present AgentLedger, a smart contract deployed on SCDO Shard0, an EVM-compatible proof-of-work (PoW) shard, which records agent registration, Merkle roots of batches of signed task messages, and pay-per-task receipts. Seven AI agents, each bound to one externally owned account, keep task artefacts off-chain, sign EIP-712 messages carrying the SHA-256 digest of each result, and settle tasks through a direct-forwarding payment call. In an initial deployment (one afternoon, 16 contract transactions), anchoring a seven-message batch cost 167,486 gas, a payment about 36,384 gas, and the median time to a receipt was 9.0 s. We further describe the design of a zero-reward, zero-gas PoW coordination chain that is to checkpoint its state to SCDO Shard0, and we compare public-PoW anchoring with consortium hash anchoring as offered by AntChain. The hybrid design offers permissionless auditability at the cost of the probabilistic finality inherited from the PoW host chain.
Cite this paper
BibTeX
@misc{zhang2026agentledger,
author = {ZHANG, Ying Willam},
title = {{SCDO Agent Ledger}: On-Chain Identity, Work Attestation and Settlement for Autonomous {AI} Agents on a Sharded {PoW} Blockchain},
year = {2026},
month = oct,
publisher = {Zenodo},
howpublished = {Preprint},
doi = {10.5281/zenodo.23119810},
url = {https://doi.org/10.5281/zenodo.23119810},
note = {SCDO Laboratory, 9Y9 PTY LTD. Open access, CC BY 4.0}
}