Whitepaper · 16
Appendices
The interface listing stays in the standard repository.
Appendix A: Interface reference
The interface listing stays in the standard repository.
What stays there
The specification, the interface sources, and the batch metadata schema.
What a public reader can know
A-REX Core extends a multi-token base with the identity of a lot, lineage when a lot is split or processed, an enforcement surface, one rule pipeline, and attestations from trusted issuers.
What this chapter withholds
Signatures, error names, storage layouts, and the schema.
How to request the text
Companies that want to implement A-REX, issue batches with it, or audit it use the early-access page. Each request is reviewed by hand. Approved readers receive read-only access to the standard repository and the reference implementation.
Terms already written
Access is for evaluation, implementation, and feedback. The material stays confidential until it is published. The written terms say the standard will be published under CC0 and that early access grants no exclusivity.
Scope of the pages that follow
The glossary, the bibliography, and the questions that follow explain terms. They are the public vocabulary.
Documents named, not copied
The standard section of this site lists the same documents.
Boundary
A page that would let a reader copy an interface stays out of this chapter.
Appendix B: Glossary
| Term | Meaning |
|---|---|
| Batch | An ERC-1155 token id with a Batch record: a lot of one commodity in one unit with shared origin and production time. |
| Re-batch | A transform whose outputs have the same commodity and unit as the inputs and whose quantities are conserved (split, merge). Open to holders in the reference implementation. |
| Processing | A transform that changes commodity, unit or quantity. Requires TRANSFORMER_ROLE in the reference implementation. |
| Lineage | The graph formed by BatchTransformed events and parentsOf. |
| Hook | A contract implementing IARexHook, registered on a token, evaluated in order on every operation. |
| Rejection code | A bytes32 returned by a hook's check; 0 means allowed; convention keccak256("NAMESPACE:NAME"). |
| Eligibility | Account-level permission to send or receive, answered by hooks flagged HOOK_ELIGIBILITY; exposed as ERC-7943 canSend/canReceive. |
| Frozen balance | Units an account holds but cannot move (setFrozenTokens); may exceed the balance. |
| Forced transfer | Movement of units by ENFORCER_ROLE without the holder's consent (ERC-7943). |
| Attestation | (batch, topic) → (issuer, reference, validity) recorded by a trusted issuer for that topic. |
| Topic | A bytes32 identifying the subject of an attestation; open; maps to ERC-735 claim topics and EAS schema ids. |
| Origin reference | originRef: a hash or reference to origin evidence; never coordinates. |
| Metadata commitment | metadataHash, keccak256 of the canonical off-chain document at uri. |
| Status | uint8 lifecycle value; 0 active, 255 retired (terminal); 1..254 issuer-defined. |
| CTE / KDE | Critical tracking event / key data element (FSMA 204). |
| DDS | Due-diligence statement (EUDR). |
| EPCIS | GS1 Electronic Product Code Information Services, the event vocabulary for traceability (version 2.0). |
| CPR / CPR-e | Cédula de Produto Rural, Brazil's crop receivable; electronic form registered with authorized entities. |
| EWR | Electronic warehouse receipt under the U.S. Warehouse Act. |
| MLETR | UNCITRAL Model Law on Electronic Transferable Records. |
| ERC-7943 (uRWA) | Universal Real World Asset interface: freeze, forced transfer, eligibility; Final May 2026. |
| ERC-3643 (T-REX) | Permissioned token standard for securities on ERC-20; Final December 2023. |
| ERC-7201 | Namespaced storage layout for upgradeable contracts. |
Appendix C: Bibliography
Standards and specifications
- Radomski, W. et al. "EIP-1155: Multi Token Standard." Ethereum Improvement Proposals, 2018.
- Vogelsteller, F., Buterin, V. "EIP-20: Token Standard." 2015.
- "ERC-165: Standard Interface Detection." 2018.
- "ERC-3643: T-REX — Token for Regulated EXchanges." Final, 15 December 2023. https://eips.ethereum.org/EIPS/eip-3643
- "ERC-7943: uRWA — Universal Real World Asset Interface." Final, 27 May 2026. https://eips.ethereum.org/EIPS/eip-7943
- "ERC-7201: Namespaced Storage Layout." 2023.
- "ERC-735: Claim Holder." 2017 (draft).
- Ethereum Attestation Service documentation.
- GS1. "EPCIS and CBV Standard 2.0." 2022. GS1 US. "EPCIS Recommendations for FSMA 204 Critical Tracking Events." 2024.
- UN/CEFACT. "Recommendation No. 20: Codes for Units of Measure Used in International Trade."
- IETF RFC 8785. "JSON Canonicalization Scheme (JCS)." 2020.
- OpenZeppelin Contracts 5.x documentation; OpenZeppelin and T-REX Network partnership announcement, July 2026.
Regulation and law
- FDA. "Requirements for Additional Traceability Records for Certain Foods." Final rule, Federal Register 87(219), 2022; "Compliance Date Extension," Federal Register, 7 August 2025.
- Regulation (EU) 2023/1115 (Deforestation); Regulation (EU) 2025/2650 (amendment); Council of the EU press release, 18 December 2025.
- Regulation (EU) 2023/1114 (MiCA); ESMA Guidelines on the qualification of crypto-assets as financial instruments, December 2024.
- European Data Protection Board. "Guidelines 02/2025 on processing of personal data through blockchain technologies," version 2.0, 7 July 2026.
- SEC. Release No. 33-11412, 17 March 2026. SEC v. W.J. Howey Co., 328 U.S. 293 (1946).
- GENIUS Act, Public Law 119-27 (2025); implementing regulations, Federal Register, 18 August 2026.
- Uniform Commercial Code, 2022 Amendments, Article 12 (Controllable Electronic Records).
- U.S. Warehouse Act; 7 CFR Part 869 (Electronic Warehouse Receipts).
- UNCITRAL. "Model Law on Electronic Transferable Records." 2017. United Kingdom, Electronic Trade Documents Act 2023.
- Comisión Nacional de Valores (Argentina). Resolución General 1150/2026. Ley 9.643 (warrants).
- Brazil. Lei 8.929/1994, Lei 13.986/2020 (CPR); Lei 11.076/2004 (CDA/WA); CVM Resolução 88 and Consulta Pública SDM 05/2025.
- Verra. "Verra Addresses Crypto Instruments and Tokens." 2022; VCS Program Guide.
- Directive (EU) 2024/825 (empowering consumers for the green transition).
Research and industry
- Zhang, P., Schmidt, D. C. "Blockchain Applications in Food Supply Chain Management: A Systematic Review." Journal of Food Engineering, 279, 2020.
- Caro, M. P. et al. "Blockchain-based Traceability in Agri-Food Supply Chain Management." IEEE, 2018.
- FAO. "The State of Food and Agriculture." 2023.
- World Bank. "Future of Food: Harnessing Digital Technologies to Improve Food System Outcomes." 2022.
- ERC3643 Association. "History of ERC-3643"; ISO TC 307 standardization initiative announcement.
- Chainlink. "Automated Compliance Engine (ACE): Technical Overview." 2025–2026.
Appendix D: Templates
Worked examples of a hook, a deployment, and a metadata document stay in the repositories.
Why they stay there
Those examples are enough to copy an implementation. This public chapter explains terms and consequences.
Where they live
They ship with the standard repository and the reference implementation, for readers whose early-access request has been approved.
Appendix E: FAQ
Is A-REX an ERC? Not yet. The specification is written in ERC format and will be submitted after a production deployment, independent implementations and an audit. No number has been assigned; names in the code do not use the ERC prefix.
Do I have to use ARexToken? The reference is one implementation. The interfaces belong to the normative text.
Do I have to use the reference hooks? They are demonstrations. Readers with access can read them in the reference repository.
Can a hook block a forced transfer? It can return a code for OP_FORCED_TRANSFER, and the token will revert. Reference hooks do not; a hook that governs enforcement (e.g. requiring an order reference) may.
Where do coordinates go? In restricted off-chain storage referenced from metadata, never on-chain.
How do I represent a future harvest? producedAt = 0; gate transfers with ExpiryHook(allowPreHarvestTransfers).
Is quantity conserved in transform? Not by the standard; the reference allows any holder to re-batch when it is conserved and requires TRANSFORMER_ROLE otherwise.
Is the token a security? The standard does not decide. The offer does. Ask counsel; the enforcement surface is there whatever the answer.