PowerSync Migration Check: Realm Sync & Data API

PowerSync Migration Check: Realm Sync & Data API — finds the line

Sample orders.ts (22 lines): 6 findings from 16 rules. Each finding names the dead MongoDB call on the left and the PowerSync replacement on the right.

MongoDB deprecated Atlas Device Sync, the Atlas Device SDKs (Realm Sync), the Atlas Data API and custom HTTPS Endpoints in September 2024. All of them reached end-of-life on 2025-09-30. Code that still logs in through Realm.App, opens a Flexible Sync session or posts to data.mongodb-api.com no longer syncs. PowerSync's MongoDB module reached general availability in March 2025 and is the migration path MongoDB pointed Device Sync users to.

Hub page and web version: https://getreadystack.com/tools/powersync-migration-check

Yardstick: every rule is measured against MongoDB's end-of-life notice for Device Sync, the Data API and HTTPS Endpoints (2025-09-30) and the PowerSync client API (PowerSyncDatabase, connect, fetchCredentials, uploadData, Sync Rules).

What it checks (16 rules)

id	finds	PowerSync replacement
RS01	`realm-web` import	`@powersync/web` / `@powersync/react-native`
RS02	`new Realm.App({ id })`	`new PowerSyncDatabase({ schema })` + `db.connect(connector)`
RS03	Flexible Sync config (`flexible: true`, `flexibleSyncConfiguration()`)	Sync Rules `bucket_definitions`
RS04	`subscriptions.update/add`	server-side Sync Rules
RS05	`partitionValue`	bucket parameter
RS06	Data API base URL `.../endpoint/data/v1`	your backend + MongoDB driver, or the local copy
RS07	custom HTTPS Endpoint URL	your own API; writes via `uploadData()`
RS08	`api-key` header sent to the Data API	short-lived JWT from `fetchCredentials()`
RS09	`/action/find`, `insertOne`, `aggregate` …	`db.getAll` / `db.watch` / `db.execute`
RS10	`Realm.Credentials.*` login	your auth provider's JWT
RS11	`user.mongoClient()`	local SQL query
RS12	`user.functions.*` / `callFunction`	endpoint on your backend
RS13	`@realm/react` `AppProvider` / `UserProvider`	`PowerSyncContext.Provider`, `useQuery`
RS14	`syncSession`, `uploadAllLocalChanges`	`connect` / `disconnect` / `waitForFirstSync`
RS15	RealmSwift / `io.realm.kotlin.mongodb` / `package:realm` used with sync	PowerSync Swift, Kotlin or Dart SDK
RS16	App Services client API URL	your auth and API

Files: .js .jsx .ts .tsx .mjs .swift .kt .dart. Comment lines are skipped.

Why not just grep for "realm"

Local-only Realm databases still work: the SDKs stayed open source. A grep for realm flags every schema and query you can keep. These rules only fire on the sync, Data API, endpoint and App Services login paths that stopped, and each finding carries the replacement call.

The date input

The check takes two inputs: the source text and a date. The date sets the clock on every message: before 2025-09-30 a finding is a warning with the days left; on or after it, an error with the days since sync stopped.

Free and full version

Free, no key: open a file and run the check; every finding appears in the Problems panel and in the web version. The full version scans the whole workspace and saves one Markdown migration report (file, line, dead call, PowerSync replacement) for your team, unlocked with a licence key.

Privacy

Nothing leaves your machine. The engine is one JavaScript file with a JSON rule list (engine.js, rules.json); the web version runs the same file in the browser.

PowerSync Migration Check: Realm Sync & Data API

ReadyStack

PowerSync Migration Check: Realm Sync & Data API

What it checks (16 rules)

Why not just grep for "realm"

The date input

Free and full version

Privacy