@accord-protocol/rails-rosen

Accord rail adapter for Rosen-bridged stablecoins on Ergo — rsUSDT, rsUSDC, rsBTC. Same on-chain primitive as rails-ergo (R4 reserve / R6 task-hash on an Ergo Note), but the value lives in a wrapped-token amount carried in the box's tokens[] array, not in the box's nanoERG value field.

Install

npm install @accord-protocol/rails-rosen @accord-protocol/rails @accord-protocol/core
# peer deps for non-mock use:
npm install ergo-agent-pay ergo-agent-rosen

Token registry — caller-supplied

Token ids differ by Rosen network, so the rail adapter does NOT bake constants in. Pass a RosenTokenRegistry for the network you are testing:

import { createRosenRailAdapter } from "@accord-protocol/rails-rosen";

const ROSEN_TOKENS = {
  rsUSDT: { tokenId: "<64 hex>", decimals: 6 },
  rsUSDC: { tokenId: "<64 hex>", decimals: 6 },
  rsBTC:  { tokenId: "<64 hex>", decimals: 8 },
};

const rail = createRosenRailAdapter({ ops: rosenAgent, tokens: ROSEN_TOKENS });

The agreement's price.currency must be one of { rsUSDT, rsUSDC, rsBTC }, AND the registry must have that currency, AND the registry's decimals must match agreement.price.decimals. All three rails-rosen-specific rejections — CURRENCY_NOT_SUPPORTED, CURRENCY_NOT_REGISTERED, INVALID_PAYMENT_SHAPE (decimals mismatch) — fire here.

Buyer payment-proof shape

{
  "note_box_id": "<64 hex>",
  "task_output": "{\"word_count\":2}",
  "receiver_address": "9XSeller..."
}

Same shape as rails-ergo. The on-chain Note's R4/R5/R6/R7 layout is identical; the wrapped-token value lookup happens against the box's tokens[] array.

verifyPayment checks (in order)

1. Shape — note_box_id 64-hex, task_output present.
2. Currency / registry — currency in {rsUSDT,rsUSDC,rsBTC}, registry has it, decimals match (rejections: CURRENCY_NOT_SUPPORTED, CURRENCY_NOT_REGISTERED, INVALID_PAYMENT_SHAPE).
3. Note exists on chain (rejection: NOTE_NOT_FOUND).
4. Not expired (rejection: NOTE_EXPIRED).
5. Reserve binding (rejection: RESERVE_MISMATCH).
6. Task-hash binding — blake2b256(task_output) === R6 (same as Ergo) (rejections: TASK_HASH_MISSING, TASK_HASH_MISMATCH).
7. Token presence — tokens[].tokenId == registry[currency].tokenId (rejection: TOKEN_NOT_PRESENT).
8. Token amount — carried token amount ≥ decimalToBaseUnits(price.amount, decimals) (rejection: INSUFFICIENT_VALUE).

On success: payment_id = note.boxId.

settle

Calls ops.redeemNote(noteBoxId, taskOutput, receiverAddress?) and emits a Settlement Receipt with:

• rail: "rosen"
• mode: "note_redeemed" (per-rail allow-list per ACCORD-003: note_redeemed | reserve_refunded | batch_settled)
• status: "settled" (or "pending" if redeemNote returns submitted: false)

Error codes (10)

INVALID_PAYMENT_SHAPE
NOTE_NOT_FOUND
NOTE_EXPIRED
RESERVE_MISMATCH
TASK_HASH_MISSING
TASK_HASH_MISMATCH
CURRENCY_NOT_SUPPORTED
CURRENCY_NOT_REGISTERED
TOKEN_NOT_PRESENT
INSUFFICIENT_VALUE

What's NOT here

• Token-id constants for mainnet/testnet. Caller-supplied registry on purpose — Rosen Bridge updates these and we don't want stale constants baked in.
• The bridge itself. This adapter assumes wrapped tokens are already on Ergo. The actual wrap (Ethereum/Bitcoin/Cardano → Ergo) flow lives in ergo-agent-rosen and is a separate concern.
• Refunds. Rosen Notes self-refund through the Ergo predicate, same as plain Ergo Notes.

License

MIT.