@unruggable/gateways/dist/esm/beacon.mjs

Trustless Ethereum Multichain CCIP-Read Gateway

import { isHexString } from 'ethers/utils';
import { sha256 } from 'ethers/crypto';
export async function fetchBeaconData(url) {
    try {
        const res = await fetch(url);
        if (!res.ok)
            throw `HTTP ${res.status}`;
        const { data } = await res.json();
        if (!data)
            throw 'expected "data"';
        return data;
    }
    catch (err) {
        throw new Error(`${url}: ${err}`);
    }
}
// https://ethereum.github.io/beacon-APIs/#/Beacon/getBlobSidecars
function isSidecar(sidecar) {
    return (sidecar instanceof Object &&
        'blob' in sidecar &&
        'kzg_commitment' in sidecar &&
        isHexString(sidecar.blob) &&
        sidecar.blob.length == 262146 &&
        isHexString(sidecar.kzg_commitment) &&
        sidecar.kzg_commitment.length == 98);
}
// https://github.com/ethereum/go-ethereum/blob/c1ff2d8ba973f9f7ebfbf45e3c36f8d3299846ba/crypto/kzg4844/kzg4844.go#L154
function blobVersionHashFromKzgCommitment(kzgCommitment) {
    return '0x01' + sha256(kzgCommitment).slice(4);
}
export async function fetchSidecars(beaconAPI, blockId) {
    const sidecars = await fetchBeaconData(`${beaconAPI}/eth/v1/beacon/blob_sidecars/${blockId}`);
    if (!Array.isArray(sidecars))
        throw new Error(`expected blob sidecars: ${blockId}`);
    return Object.fromEntries(sidecars
        .filter(isSidecar)
        .map((x) => [blobVersionHashFromKzgCommitment(x.kzg_commitment), x]));
}