Atrium SDK

TypeScript SDK for Atrium — a three-tranche CDO (Junior / Mezzanine / Senior) over a single yield strategy on Arbitrum. Deposits use the base asset USDai; withdrawals are denominated in the output token sUSDai. Yield flows Senior-first; losses flow Junior-first (the waterfall).

Read-focused: wraps a viem PublicClient for on-chain reads and returns viem write requests you submit with your own WalletClient.

Install

pnpm add atrium-sdk viem

Quick start

import { AtriumSDK, TrancheId, ExitMode } from "atrium-sdk";
import { arbitrum } from "viem/chains";

const sdk = new AtriumSDK({
  rpcUrl: "https://arb1.arbitrum.io/rpc",
  chain: arbitrum,
  addresses: {
    cdo:            "0xbe0310f4F343Ba7C34815e8AB67752cdE05cD858",
    accounting:     "0x3c142b82aD93A7308BE7fd83a06BD1Bc1AF613c7",
    strategy:       "0xb7E576764BF0496702C868B504D86d062A7b80c8",
    jrVault:        "0x19268f989886eE0599e5ebd8Ac559585619dd64a",
    mzVault:        "0x52c91B6ecD4C95d9BF43F34ca6217754925Efc9f",
    srVault:        "0xe1AB89fF238C289862bfFA41b6b6C062b2829d3a",
    sharesCooldown: "0x95b44cFCB08606B1d28e4678De9859Eda3e3b093",
    usdai:          "0x0a1a1a107e45b7ced86833863f482bc5f4ed82ef",
    susdai:         "0x5f02c1bec4ad5de9b7abf999c1f0854d4836a049",
  },
});

// Reads
const tranches = await sdk.getAllTranches();
const health   = await sdk.getProtocolHealth();   // coverage, TVLs, minCoverage
const apr      = await sdk.getApr();               // aprSrt / aprBase / aprTarget / index
const preview  = await sdk.previewWithdraw(TrancheId.JUNIOR, shares, user);

Addresses above are from ignition/deployments/chain-42161/deployed_addresses.json. Regenerate after every deploy.

Deposit (USDai)

import { createWalletClient, custom } from "viem";
const wallet = createWalletClient({ chain: arbitrum, transport: custom(window.ethereum) });

// 1) approve USDai for the tranche vault
await wallet.writeContract({ ...sdk.buildApprove(sdk.addr.usdai, sdk.addr.jrVault, amount), account });
// 2) deposit
await wallet.writeContract({ ...sdk.buildDeposit(TrancheId.JUNIOR, amount, account), account });

Withdraw (receive sUSDai)

Withdrawals must use the sUSDai meta-token path — buildWithdraw does this for you (it calls redeem(sUSDai, shares, receiver, owner)). The plain ERC-4626 redeem(shares,…) routes the base asset which the v1 Strategy rejects.

const req = sdk.buildWithdraw(TrancheId.JUNIOR, shares, account, account);

// ALWAYS simulate first — surfaces coverage / pause / mode reverts (viem decodes the custom error)
await sdk.publicClient.simulateContract({ ...req, account });
await wallet.writeContract({ ...req, account });

If previewWithdraw(...).mode === ExitMode.SharesLock, the shares are escrowed in the SharesCooldown silo for cooldownSeconds. Poll getUserWithdrawRequests(user); once isClaimable, finalize:

await wallet.writeContract({ ...sdk.buildFinalizeCooldown(TrancheId.JUNIOR, account), account });

API

| Method | Returns | |---|---| | getTranche(id) / getAllTranches() | TVL, supply, share price, indicative APR | | previewDeposit(id, assets) | shares minted, share price | | previewWithdraw(id, shares, owner) | mode, fee, cooldown, net USDai + sUSDai out | | getProtocolHealth() | coverage, minCoverage, per-tranche TVL, reserve, strategy TVL | | getApr() | aprSrt, aprBase, aprTarget, srtTargetIndex (all 1e18) | | getUserWithdrawRequests(user) | pending share-lock requests across tranches | | getUserPortfolio(user) | shares + USDai value per tranche | | getTokenBalance / getTokenAllowance / getShareBalance | ERC-20 / share reads | | buildApprove / buildDeposit / buildWithdraw / buildFinalizeCooldown | viem write requests |

Admin ABIs (PRIME_CDO_ADMIN_ABI, ACCOUNTING_ADMIN_ABI, SHARES_COOLDOWN_ADMIN_ABI, STRATEGY_ADMIN_ABI, ACM_ABI) are exported for governance tooling.

Notes & gotchas

• TrancheId matches the on-chain TrancheKind enum: JUNIOR=0, MEZZANINE=1, SENIOR=2.
• Withdraw = sUSDai overload only (handled by buildWithdraw).
• Simulate before write to catch CoverageBelowMinimum, WithdrawalsDisabled, RedemptionParamsMismatch.
• APR / fee / coverage values are 1e18-scaled (0.04e18 = 4%).
• Reads reflect the last updateAccounting(); for an exact live quote, simulateContract the entry.
• Alt-token (sUSDai) deposits are intentionally omitted — the on-chain meta-deposit path has an open issue (maxWithdraw check on ERC-7540 sUSDai). Use the USDai deposit path.

Build

pnpm install
pnpm build        # tsup → dist (cjs + esm + d.ts)
pnpm typecheck