Somnia Price Feeds

Spot and mark prices onchain, about once a second, free to read.

Somnia Price Feeds is a push-based crypto price feed. A self-re-arming onchain schedule ticks roughly once a second. Each tick sends a request to a Somnia Agents subcommittee that prices every tracked pair across exchanges, and the median is written back into contract storage. Consumers read those cells: there is no subscription to buy, no fee per read and no callback.

Two prices are published for each pair:

The onchain feed is the supported surface. An indexer also serves the history for charts and monitoring, but nothing that moves value should read from it.

Addresses

PriceFeedScheduler is a UUPS proxy. Its address stays fixed across upgrades, so bind to the proxy, never to an implementation.

Conventions

• Prices are unsigned and scaled by 10 ** decimals(), which is 18 on both networks today. Read decimals() once rather than hardcoding it.
• Timestamps are Unix milliseconds, not seconds. A cell's timestamp is block.timestamp * 1000, so it is second-granular and shared by every pair written in the same tick. sourceUpdatedAtMs carries millisecond precision.
• Cadence. Ticks fire on a fixed grid, just after each whole second. A tick delivered very late skips one grid point rather than firing twice back to back.
• Pairs are ccxt-style strings, such as "BTC/USDC".
• Reads never revert on stale or missing data. A pair that is untracked, removed or not yet written returns zero. You decide what is too old: the feed never invents a value. The *OrRevert helpers revert on your bound, not the feed's.

Read a price safely

latest() returns (price, updatedAtMs) and never reverts, so a consumer that forgets to check both fields will trade on a zero or an hour-old price. Use the one-call safe form instead:

// Copy IQualifiedPriceFeed into your project, or declare just the functions you call:
// the feed publishes no ABI package today.
import {IQualifiedPriceFeed} from "./IQualifiedPriceFeed.sol";

contract Consumer {
    IQualifiedPriceFeed constant FEED =
        IQualifiedPriceFeed(0x1998C88D54a240b8C671493f27f58eC416b81D7F);

    uint256 constant MAX_AGE_MS = 5_000; // 5 missed ticks tolerated

    function settle() external view returns (uint256 btc) {
        // Reverts NoPrice() if never written, StalePrice(ageMs, maxAgeMs) if too old.
        btc = FEED.latestOrRevert("BTC/USDC", MAX_AGE_MS);
    }
}

Set maxAgeMs by what a stale price would cost you. Settlement and liquidation want single-digit seconds at a one-second cadence; display can be generous. A bound below the tick cadence means nothing, because cell timestamps are second-granular.

Next steps

• Reading prices: the four read interfaces, the quality fields and the mark hazard.
• Feed liveness: tell a dead feed from one unpriced pair.
• Pairs and events: the tracked pairs, the events and how to request a new pair.
• Reference: every call and what it returns, and the historical-data indexer.

Somnia Price Feeds is built on Somnia Agents and Somnia Reactivity, the same pieces as the Somnia Oracle. Third-party feeds from Stork, DIA and Protofire also run on Somnia Mainnet: see Oracles.