PriceHub

A gas-optimized, bit-packed multi-feed price registry. You can use the FeedCodec library (see PriceHub contract interface SDK) for single-slot storage compression and efficient data retrieval via hand-written assembly.

PriceHub contract interface SDK:
https://drive.google.com/file/d/1OOxqEoSRPP6zzFoScpMl4G9NH8OHbVj0/view?usp=sharing

PriceHub exposes two price query styles:

1. Standard interface (Decoded view).
2. Compact interface (Bare-metal view): an efficient access pattern where the compact path returns packed data via staticcall to minimize cross-contract gas. You must integrate the FeedCodec library in your own contract logic (see PriceHub contract interface SDK) to decode the raw bytes32 words.

Functions

Name	Description	View type
fetch	Returns a human-readable price snapshot for a given data source	Decoded view
fetchBatch	Returns an array of decoded snapshots for multiple data sources	Decoded view
fetchCompact	Returns the raw 256-bit packed word for a given data source	Bare-metal view
fetchCompactBatch	Returns an array of raw packed words for multiple data sources	Bare-metal view
decimals	Returns the decimal precision used for prices
description	Returns a human-readable description of this hub
version	Returns the version number of this hub implementation
isAuthorizedCaller	Checks whether a given account is on the authorized-caller whitelist

1. fetch

Returns a human-readable price snapshot for a given data source.

Note: Executes only if the calling contract has been pre-whitelisted by the protocol. You must supply the querying contract address to obtain read access.

function fetch(bytes4 feedId) external view returns (PriceSnapshot memory priceSnapshot)

Parameters

• feedId: 4-byte unique identifier.

Return values

• priceSnapshot: Decoded struct with price and timestamps. If the feedId does not exist, returns a zero-initialized snapshot.

1.1 PriceSnapshot struct definition

Records a price snapshot at a specific point in time.

/**
 * @notice Price snapshot at a specific point in time
 * @dev Fields are physically packed to specific bit widths for storage efficiency:
 * @param price Fixed-point aggregated price with 18 decimal places (80 bits)
 * @param aggregatedTs Timestamp when off-chain aggregation occurred (48 bits)
 * @param onchainTs Timestamp when the price was packed and stored on-chain (48 bits)
 */
struct PriceSnapshot {
    uint80 price;
    uint48 aggregatedTs;
    uint48 onchainTs;
}

2. fetchBatch

Returns decoded snapshots for multiple data sources.

Note: Executes only if the calling contract has been pre-whitelisted by the protocol. You must supply the querying contract address to obtain read access.

function fetchBatch(bytes4[] calldata feedIds) external view returns (PriceSnapshot[] memory priceSnapshots)

Parameters

• feedIds: Array of 4-byte unique identifiers.

Return values

• priceSnapshots: Array of decoded PriceSnapshot structs. For any non-existent feedId, the corresponding slot contains a zero-initialized snapshot.

3. fetchCompact

Returns the raw 256-bit packed word for a given data source.

For gas-sensitive applications, prefer this method to obtain the compact word and decode it inside your business contract using FeedCodec. This minimizes gas overhead associated with staticcall return data.

Note: Executes only if the calling contract has been pre-whitelisted by the protocol. You must supply the querying contract address to obtain read access.

function fetchCompact(bytes4 feedId) external view returns (bytes32 packed)

Parameters

• feedId: 4-byte unique identifier.

Return values

• packed: Raw storage word with physical layout: [reserved (80b)][on-chain timestamp (48b)][aggregation timestamp (48b)][price (80b)]. If the ID does not exist, returns bytes32(0).

4. fetchCompactBatch

Returns an array of raw packed words for multiple data sources.

For gas-sensitive applications, prefer this method to obtain compact words and decode them in your business contract with FeedCodec. This minimizes gas overhead associated with staticcall return data.

Note: Executes only if the calling contract has been pre-whitelisted by the protocol. You must supply the querying contract address to obtain read access.

function fetchCompactBatch(bytes4[] calldata feedIds) external view returns (bytes32[] memory packedList)

Parameters

• feedIds: Array of 4-byte unique identifiers.

Return values

• packedList: Array of raw 256-bit packed words. For any non-existent feedId, the corresponding slot contains bytes32(0).

5. decimals

Returns the price precision shared by all feeds in this hub.

function decimals() external view returns (uint8 decimals)

Parameters

(none)

Return values

• decimals: Constant precision for price sources (typically 18).

6. description

Returns a human-readable description of this hub.

function description() external view returns (string memory description)

Parameters

(none)

Return values

• description: Human-readable description of this hub.

7. version

Returns the version number of this hub implementation.

function version() external view returns (uint256 version)

Parameters

(none)

Return values

• version: Version number.

8. isAuthorizedCaller

Checks whether a given account is on the authorized-caller whitelist.

function isAuthorizedCaller(address account) external view returns (bool isAuthorizedCaller)

Parameters

• account: Address of the contract to query.

Return values

• isAuthorizedCaller: true if that contract address is on the whitelist.