A price oracle built to resist single-source manipulation

Shomei combines prices from multiple independent exchanges and on-chain pools, and discards outliers before publishing — so one bad source has far less influence on the published price.

You can't verify most oracles — you just trust them

Most price oracles rely on one exchange, one on-chain pool, or one signing key. If any of those fails or gets compromised, the price is wrong too, and there's no independent way to tell.

How Shomei aggregates a price

Shomei's keeper pulls prices from up to seven centralized exchanges — Binance, Coinbase, Binance.US, Kraken, KuCoin, Bybit, and Gate.io — and, for feeds configured with them, on-chain DEX pools as well. The exact source mix varies by feed: some draw from all seven exchanges, while others combine a smaller set of exchanges with on-chain DEX pools across multiple chains. Shomei's Price Feeds page shows exactly which sources go into each feed's price, so you don't have to take it on faith.

A price is only published once the minimum quorum of sources responds. The final value is a trimmed mean — outliers are discarded before averaging — which reduces the effect of any one source being wrong, slow, or compromised.

Built for easy integration

• No API key needed. Read a feed directly from the chain, or fetch a signed price from the keeper — no account or API key required.
• Permissionless submission. Anyone can submit a correctly-signed price on-chain — there's no allowlist or special capability gating who can post.
• Free to publish. Publishing a price costs nothing.
• Full price history from events. Every price post emits an on-chain event carrying the full price, so you can reconstruct a feed's history without running your own infrastructure.

Signing and key security

Shomei signs every price with an Ed25519 signature. The keeper also supports two capabilities built for stronger key security: holding signing keys in Google Cloud KMS instead of as local private keys, and a second, independently-rotatable key per feed so that compromising one key alone isn't enough to post a price.

Ready to integrate?

Read the docs to start consuming a Shomei feed.