TypeScript SDK

@tapehouse/sdk is typed reads and transaction builders for Tapehouse's contracts, on viem 2. A read takes a viem client and returns plain values. A transaction function returns a viem contract call you pass to simulateContract and writeContract, so you choose the wallet, the signer and the gas settings.

Install#

pnpm add @tapehouse/sdk viem

viem is a peer dependency (^2.57.2). The package is ESM, ships its own types, and is licensed MIT OR Apache-2.0.

Read and send#

Every function takes a chain's registry as its second argument, parsed from deployments/<chainId>.json with parseDeployments. The SDK compiles in no address.

import { readFileSync } from 'node:fs'
import { createPublicClient, createWalletClient, http } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'
import { robinhoodTestnet } from 'viem/chains'
import { accounts, band, CROSS, parseDeployments } from '@tapehouse/sdk'

const deployments = parseDeployments(JSON.parse(readFileSync('deployments/46630.json', 'utf8')))
const publicClient = createPublicClient({ chain: robinhoodTestnet, transport: http() })

const { state, low, high } = await band.quote(publicClient, deployments, 'TSLA')

const owner = '0xB986a345655097302cac8b4af6C948FfaF7f55FC'
const price = await accounts.liquidationPrice(publicClient, deployments, owner, CROSS, 'TSLA', 50_000_000n)

const wallet = createWalletClient({
  account: privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`),
  chain: robinhoodTestnet,
  transport: http(),
})
const { request } = await publicClient.simulateContract({
  ...accounts.borrow(deployments, { position: CROSS, assets: 50_000_000n, account: owner, receiver: owner }),
  account: wallet.account,
})
const hash = await wallet.writeContract(request)

An asset is its symbol as a string ('TSLA'); the SDK turns it into the bytes32 the contracts take with toBytes32. A position is CROSS, the cross position, or an asset's symbol as bytes32 for its isolated position; accounts.positions lists them. Amounts are bigint in the token's raw units: USDG has 6 decimals, Stock Tokens 18, and the band's prices are USD with 8.

Every read ends with an optional at argument, { blockNumber?: bigint }. Reads that combine several calls (repayment, lending, holding, limits, backstop.state and others) take all of them at one block, the latest by default.

Registry#

Modules#

Each module is a namespace import: import { band, accounts } from '@tapehouse/sdk'. A transaction function takes deployments and a named-argument object and returns { address, abi, functionName, args }. A read takes client, deployments, its arguments and at.

band#

The band's quote, session and halt, each asset's BandFeed, and Chainlink feeds. The band says what the values mean.

accounts#

The margin accounts. position is CROSS or an asset's bytes32.

engine#

The margin engine's requirement for any portfolio. A Portfolio is { quantities, prices }: signed amounts with 18 decimals and USD prices with 8, in the engine's order.

supply#

The vault USDG lenders deposit into.

backstop#

The gap backstop that absorbs a closure's losses.

auction#

The reopening auction. A bid is committed under a hash, then revealed. commitment computes the hash and clearingPrice the one price the contract accepts.

stockLending#

sponsorship#

The ERC-4337 side. The sponsor is the service that pays.

baskets#

A basket is keyed by its name in .tapehouse.Baskets, for example 'PAIR'.

shorts#

morpho#

gapCover#

The gap cover contract has the rules behind each call.

ABIs and errors#

The contracts' ABIs are exported as const from the build: bandAbi, bandFeedAbi, marginAbi, marginAccountsAbi, liquidatorAbi, gapBackstopAbi, reopeningAuctionAbi, stockLendingVaultAbi, supplyVaultAbi, shortPositionsAbi, basketAbi, gapCoverAbi, morphoBandOracleAbi, sponsorPaymasterAbi, stockTokenAbi, usdgAbi, wethAbi, aggregatorAbi, quoterV2Abi, uniswapV3PoolAbi, morphoBlueAbi and others. decodeRevert, decodeRevertData and errorsAbi are on the errors page.

Authorization#

An account acts for itself. For anyone else to borrow, withdraw, deposit or act on its shorts, the owner calls accounts.setAuthorization(deployments, authorized, true). Until then the call reverts with Unauthorized(caller, account). For an agent that should be bounded, accounts.setMandate caps its debt and leverage and gives it an end time.

Examples#

The package has two runnable examples. examples/devnode.ts runs the band, accounts, shorts, baskets and gap cover modules against a local Nitro dev node (PRIVATE_KEY=0x… pnpm devnode RPC_URL DEPLOYMENTS_JSON PAYLOAD_FILE, with the account owner's key). examples/sponsored.ts sends a user operation through the sponsor paymaster (PRIVATE_KEY=0x… pnpm sponsored RPC_URL BUNDLER_URL SPONSOR_URL DEPLOYMENTS_JSON).

Next#

• SDKs overview: the three SDKs side by side.
• Errors: decode a revert and fix it.
• Borrow: the same calls in a guide.