Morpho oracle

MorphoBandOracle lets a Morpho Blue market take a Stock Token as collateral priced by its band. It implements Morpho's IOracle: price() is the price of one unit of the collateral token in units of the loan token, scaled by 1e36. It answers at the band's low edge, in every state that has a price, and reverts when the band has none. It never returns zero.

Address#

The testnet registry, deployments/46630.json, lists no Morpho oracle: it has no morphoOracles group, so there is no oracle address to give for chain 46630. One oracle exists per asset in a chain's morphoOracles group when it is deployed, and the SDK reads it from there by asset name. Everything on this page is unaudited.

Read a price#

import { readFileSync } from 'node:fs'
import { createPublicClient, http } from 'viem'
import { morpho, parseDeployments } from '@tapehouse/sdk'

// A registry file whose `morphoOracles` group lists the asset.
const deployments = parseDeployments(JSON.parse(readFileSync('deployments/<chainId>.json', 'utf8')))
const client = createPublicClient({ transport: http('<rpc url>') })

const answer = await morpho.price(client, deployments, 'TSLA')

if (answer.price === undefined) {
  console.log(answer.noPrice) // 'stale', 'halted' or 'sequencerNotSettled'
} else {
  console.log(answer.price)
}

morpho.price turns a NoAnswer or SequencerNotSettled revert into a result, and reads the halt sources at the same block to tell a stale band from a halt. Any other error is thrown.

Functions#

The constructor takes the band, the asset's symbol, the loan token and the initial owner. It reverts with NoStockToken when the band names no Stock Token for the symbol and with ScaleTooLarge when the loan token has more than 29 decimals more than the collateral.

Events#

Roles and admin powers#

The owner can re-point the oracle with setBand. The only check is that the new band names the same Stock Token for the asset. Nothing checks the new band's prices, so the owner can in effect set any price: raise it, lower it, or point the oracle at a band that reverts and stop every liquidation in the market. A market on this oracle trusts the owner with that. Create a market only once owner() is a timelock, so that every re-point waits out the timelock's delay and BandSet announces it.

The band's own powers matter too. A signed halt comes from Tapehouse's halt signer and lasts an hour at a time, and the band's owner can replace that signer. See Band.

Invariants#

• The price is the low edge in every state that has a price: open, closed and degraded, a lapsed signed halt included. It is never zero.
• A band with no price reverts. Morpho Blue then refuses to borrow, to withdraw collateral against debt and to liquidate, while supplying, repaying, withdrawing what is not lent and adding collateral go on.
• No live leg is the most common cause. While the market is closed the band's one leg is the 24/7 price, live for 120 seconds after its RedStone package, so a band nobody has written to for two minutes has no price until someone calls writePrices.
• The band's price is already the token's, its ERC-8056 multiplier applied. The oracle applies no multiplier of its own and takes the loan token at par with the US dollar.
• A liquidator should call the band's writePrices with a fresh signed package and Morpho Blue's liquidate in the same transaction. A package no newer than the stored one reverts with PackageNotNewer, which means someone wrote first.

SDK#

TypeScript, module morpho in @tapehouse/sdk.

Next#

• Use the band as a Morpho oracle
• Band
• Band feeds