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+---
+arc: 1594
+title: Core Security Token Operations
+description: Issuance, redemption, and validation primitives for Algorand security tokens
+author: Ludovit Scholtz (@scholtz)
+discussions-to: https://github.com/algorandfoundation/ARCs/discussions
+status: Draft
+type: Standards Track
+category: Interface
+sub-category: Application
+created: 2025-09-03
+requires: 88, 200
+replaces:
+---
+
+# ARC-1594: Core Security Token Operations
+
+## Abstract
+
+ARC-1594 specifies core issuance, redemption, and transfer validation semantics for security tokens on Algorand. It provides deterministic pre-transfer checks and standardized status / error codes enabling wallets, exchanges, and compliance services to integrate with regulated token flows.
+
+## Motivation
+
+Security tokens require pre-trade eligibility checks (KYC/AML, jurisdiction, lock-up expirations) that are not expressible purely via permissionless transfers. ERC-1594 defines these on Ethereum; this ARC maps them to Algorand leveraging atomic transaction groups and AVM logic for predictable, low-latency enforcement.
+
+## Specification
+
+### Interfaces (ABI Recommendations)
+
+(All method identifiers in snake*case with ARC-4 type signatures. ARC-1594 methods are namespaced with `arc1594*`. Simplification: this core profile drops explicit partition parameters; partition-aware functionality is delegated to ARC-1410.)
+
+- `arc1594_issue(to: address, amount: uint256, data: bytes)`
+- `arc1594_redeem(amount: uint256, data: bytes)` (caller/self redemption)
+- `arc1594_redeemFrom(from: address, amount: uint256, data: bytes)` (owner/governance or holder-authorized redemption)
+- `arc1594_set_issuable(flag: bool)` (owner toggles global issuance enable switch)
+- `arc1594_is_issuable() -> (flag: bool)` (readonly global issuance enable flag)
+- `arc1594_transfer_with_data(to: address, amount: uint256, data: bytes)` (standard transfer emitting/accepting opaque metadata)
+- `arc1594_transfer_from_with_data(from: address, to: address, amount: uint256, data: bytes)` (allowance/operator transfer with metadata)
+
+Partitioned behavior (if needed) MUST be layered by simultaneously implementing ARC-1410; ARC-1594 then operates on the default/unrestricted partition implicitly.
+
+Note: Per-account KYC / lockup admin setter methods have been removed from the core; such compliance layers MAY be specified by an extension ARC to keep ARC-1594 minimal.
+
+### Codes
+
+Return codes:
+
+- `0` Success
+- `10` SenderNotEligible
+- `11` RecipientNotEligible
+- `12` PartitionRestricted
+- `13` AmountExceedsPartitionBalance
+- `14` GlobalTransferHalted
+- `15` LockupActive
+- `16` DocumentDisclosureRequired
+  (Code 20 removed in partitionless core profile; unknown partition is handled by ARC-1410 layer.)
+- `30` InvalidSignatureOrAuth
+- `40` InternalError
+
+Codes MUST be logged as the first 8 bytes of a log entry or written to a well-known box/state key `last-val-code` keyed by sender address. Reason strings are optional and SHOULD be UTF-8.
+
+### State Model
+
+Minimum required state keys / boxes:
+
+- Global: `halt` (uint64; 1 = transfers disabled except controller)
+- Local (per investor): `kyc` (uint64; 1 = eligible), `lockup-until` (uint64; round or timestamp), optional jurisdiction code `jur` (uint64)
+- Boxes (optional extended): `elig-<addr>` for arbitrary packed compliance flags.
+
+### Authorization
+
+Issuance / Redemption MUST be restricted to governance authority (Issuer) or delegated operators (multi-sig, logic signature) recorded in global state keys (`issuer`, `operator-<n>`). Validation is permissionless but enforces rules.
+
+### Events (Logging Conventions)
+
+Implementations SHOULD log compact structured events (CBOR or msgpack) for indexing:
+
+- arc1594_issue: tag 0x01 | addr | amount | partition (partition omitted in core partitionless profile)
+- arc1594_redeem: tag 0x02 | addr | amount | partition (partition omitted in core partitionless profile)
+
+### Failure Semantics
+
+If validation fails, the subsequent ARC-200 transfer MUST fail or be omitted. No partial state changes should misrepresent balances.
+
+## Security Considerations
+
+- Ensure replay protection: include group ID or txn ID in validation ephemeral state so old approvals can't be reused.
+- Prevent redemption of locked or escrowed partitions unless explicitly allowed.
+- Use constant-time comparisons for signature attestations if verifying off-chain oracle attestations.
+
+## Reference Types
+
+Suggested canonical encoding for address lists in boxes: msgpack array of raw 32-byte addresses.
+
+## Compliance Oracle Pattern (Optional)
+
+An oracle signs `(from, to, amount, partition, round, expiryRound)`; contract verifies signature against authorized oracle key, bypassing on-chain local flags where policy allows.
+
+## Backwards Compatibility
+
+Can coexist with a plain ARC-200 token; if wallet ignores validation flow, controller enforcement can still reverse unauthorized transfers (with ARC-1644) though this is discouraged for UX predictability.
+
+## Reference Implementation
+
+[arc1594.algo.ts](https://github.com/scholtz/arc-1400/blob/main/projects/arc-1400/smart_contracts/security_token/arc1594.algo.ts)
+
+## Rationale
+
+Partition-independent core keeps minimal surface, delegating complexity to optional ARCs (1410, 1643, 1644) for modular adoption.
+
+## Copyright
+
+CC0 1.0 Universal.