Skip to content

fix: accept the ephemeral oracle discriminator for the price feed #112

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
dhruvja merged 1 commit into from
Jul 7, 2026
Merged

fix: accept the ephemeral oracle discriminator for the price feed #112

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 13 additions & 9 deletions binary-prediction/app/src/lib/binaryPrediction.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -275,20 +275,24 @@ function formatOraclePrice(raw: bigint, exponent: number) {
return `${whole}.${fraction}`.replace(/\.?0+$/, "");
}

// Anchor account discriminator for pyth_solana_receiver_sdk's PriceUpdateV2
// (first 8 bytes of sha256("account:PriceUpdateV2")). Validating it before
// reading fixed offsets makes a wrong/renamed account fail clearly instead of
// silently decoding garbage into the UI.
const PRICE_UPDATE_V2_DISCRIMINATOR = Buffer.from([
34, 241, 35, 99, 157, 126, 244, 205,
]);
// Accepted 8-byte account discriminators for the SOL/USD price feed. Both
// accounts share the PriceUpdateV2 field layout read below; validating the
// discriminator makes a wrong/corrupt account fail clearly instead of silently
// decoding garbage into the UI. The demo reads MagicBlock's ephemeral oracle
// (its own discriminator), but the canonical Pyth PriceUpdateV2 discriminator
// (sha256("account:PriceUpdateV2")) is accepted too so a real Pyth feed works.
const PRICE_UPDATE_DISCRIMINATORS = [
Buffer.from([234, 161, 14, 36, 172, 239, 15, 232]), // ephemeral oracle
Buffer.from([34, 241, 35, 99, 157, 126, 244, 205]), // Pyth PriceUpdateV2
];

export function decodeOraclePrice(data: Buffer): OraclePrice {
if (data.length < 133) {
throw new Error("Oracle price account has invalid data");
}
if (!data.subarray(0, 8).equals(PRICE_UPDATE_V2_DISCRIMINATOR)) {
throw new Error("Oracle account is not a Pyth PriceUpdateV2 account");
const discriminator = data.subarray(0, 8);
if (!PRICE_UPDATE_DISCRIMINATORS.some((d) => discriminator.equals(d))) {
throw new Error("Oracle account is not a recognized price-update account");
}

// PriceUpdateV2 fields from pyth_solana_receiver_sdk, after the discriminator.
Expand Down
Loading