lexshift

lexshift helps you work with evolving AT Protocol lexicons by identifying record revisions and shifting records to a target revision.

It is designed for schema evolution workflows where records need to remain usable across multiple lexicon versions.

Full documentation is available at lexshift.lou.gg.

Installation

npm install lexshift

API overview

• identify(record, options?): Detects which lexicon revision a record matches.
• shift(record, targetRevision, options?): Migrates a record to a requested revision.

Both functions support a historyProvider option so you can supply historical lexicons when the current revision does not match.

Example

import { identify, shift } from "lexshift";

const record = {
  $type: "com.example.profile",
  name: "Ada",
};

const historyProvider = async ({ nsid, current }) => {
  const previousLexicons = await fetchHistorySomehow(nsid, current.revision);
  return previousLexicons.map((candidate) => ({
    revision: candidate.revision,
    lexicon: candidate.lexicon,
    cid: candidate.cid,
  }));
};

const identified = await identify(record, { historyProvider });

const migrated = await shift(record, 3, { historyProvider });

Notes

• record.$type must contain a valid NSID.
• If no matching revision is found, the functions throw an error.