17 documents
Decision records
Sixteen architectural decision records in the IBM template: context, options, decision, implications.
Every structural choice in A-REX Core is recorded as a decision: the situation that forced it, the options weighed, what was decided, why, what it costs, and where it is implemented and tested. Read a record before proposing to change what it decided.
How the records are organised
| Area | Records |
|---|---|
| Scope and legal position | 001 interfaces only · 013 legal neutrality |
| Token and data model | 002 ERC-1155 · 006 open codes · 008 no personal data · 011 pre-harvest lots |
| Enforcement and control | 003 ERC-7943 · 010 roles and terminal RETIRED · 012 forced transfers |
| Extensibility | 004 one hook interface · 005 bytes32 codes · 007 lineage through transform |
| Reference implementation | 009 attestation companion · 014 carbon wrapper · 015 oracle rounds · 016 UUPS and ERC-7201 |
Each card below shows the decision in one sentence. The index explains the template and draws the dependencies between records.
Documents
Index of decisions
Sixteen recorded decisions behind A-REX Core: for each one, the situation that forced it, the options that were weighed, what was decided, why, and where the decision is implemented and tested.
ADR-001: Standardize interfaces only; modules stay outside the standard
Only the specification and the interfaces in contracts/standard/ are normative; the reference token, hooks and extensions are implementations that may change without changing the standard.
ADR-002: ERC-1155 as the base token standard
A-REX Core extends ERC-1155: one contract holds many lots, each lot is an id with a quantity, and every conformant token is a complete ERC-1155 token.
ADR-003: Adopt ERC-7943 (multi-token variant) verbatim for enforcement
Freezing, forced transfers and eligibility come from ERC-7943, copied verbatim, so that liens, seizures and embargoes have the shape compliance tooling already recognizes.
ADR-004: One hook interface, flags cached at registration, ordered evaluation
Every rule is an independent IARexHook contract; the token calls the hooks in registration order, using flags cached at registration, and stops at the first rejection.
ADR-005: bytes32 rejection codes instead of strings or hook-side custom errors
A hook refuses by returning a namespaced bytes32 code; the token reverts with ARexHookRejected(hook, code) and exposes the same code before the transaction through transferCheck.
ADR-006: Open codes instead of closed enumerations
Commodity, unit, lifecycle status and attestation topic are open codes (bytes32 or uint8), so a new crop, unit, lifecycle or certification never requires a new version of the standard.
ADR-007: Lineage through an atomic transform operation
Split, merge and processing are one operation, transform, which burns inputs, mints outputs, records their parents on-chain and emits one event that maps to an EPCIS TransformationEvent.
ADR-008: No personal data on-chain
The batch record never holds coordinates or natural-person identifiers; origin is a reference to evidence, and precise geodata lives off-chain behind access control.
ADR-009: Attestations implemented in a companion contract
The reference implements IARexAttest in a separate ARexAttestations contract bound to one token, because embedding it pushed the token over the EIP-170 size limit.
ADR-010: Authority comes from roles, never from balances; RETIRED is terminal
Only an account with STATUS_ROLE can change a lot's status or metadata; holding units grants no authority, and once a lot is RETIRED (255) no one can revive it.
ADR-011: Pre-harvest lots are first-class (producedAt == 0)
A batch may be created before the goods exist: producedAt == 0 means not yet produced, so forwards, warrants and crop receivables use the same token as the delivered lot.
ADR-012: Forced transfers bypass pause and eligibility but still run hooks
A forced transfer works while the token is paused and against ineligible or frozen accounts, but it still passes through the hooks with OP_FORCED_TRANSFER, so a hook can require an order reference.
ADR-013: Legal neutrality: the standard does not classify the token
The standard takes no position on whether a batch token is a security, a commodity or a document of title; it ships the enforcement surface every classification needs and leaves policy to hooks and counsel.
ADR-014: Carbon as a registry-immobilised wrapper plus attestations; no primary issuance
Carbon credits are never created on-chain: the reference records credits immobilised in their registry, links tonnes to lots, mirrors retirement and publishes an attestation.
ADR-015: Oracle rounds keyed by round number, not wall clock
Commodity prices are agreed in numbered rounds per commodity, finalized at quorum with the median, so results do not depend on when submissions fall relative to a time bucket.
ADR-016: UUPS upgradeability with ERC-7201 storage and a per-file optimizer setting
The reference token is a UUPS proxy with ERC-7201 namespaced storage, compiled with optimizer.runs = 1 so that it fits EIP-170 at 24,136 bytes.