Supapower

Supapower is a sync engine that keeps a local PGlite database in sync with Supabase, so an application can read and write locally and stay usable while offline. It is inspired by PowerSync.

Status: 0.3.0. Both directions of the sync work; the public API may still change before 1.0.

Why Supapower

• Nothing new to deploy - Supabase's Data API and Realtime are the sync protocol; no sync service, no replication slot, no second bill.
• Real Postgres on both ends - the client is PGlite, not SQLite: the same SQL, the same types, and migrations you can lift from the server.
• Your RLS policies are the sync rules - downloads and writes go through PostgREST as the signed-in user, so there is no second authorization language to keep in step.
• Two-way sync that merges per column - offline writes queue per transaction and upload only the columns that changed, so two people editing different fields of a row both keep their edit.
• Three lines to adopt - a PGlite extension plus one sync() call; no codegen, no schema DSL, no client-side query language to learn.
• Small, permissive, batteries included - Apache-2.0 with zero runtime dependencies, plus a SharedWorker multi-tab host, React and Vue bindings, and a typed status and event API.

Longer version, and how it compares with RxDB, PowerSync, Electric and Zero: supapower.dev/why-supapower · supapower.dev/comparison

Documentation

Everything below, except the examples section, is for working with the monorepo. For documentation on the Supapower library see the supapower package's readme, or the full documentation site at supapower.dev.

Packages

Package	Description
supapower	The main package for Supapower - a PGlite extension that integrates with Supabase and syncs data between them
@supapower/worker	A more stable drop-in replacement for PGlite's built-in multi-tab worker, using a SharedWorker with automatic fallback - works with plain PGlite, no Supapower required
@supapower/react	React hooks for Supapower: PGlite live queries plus sync status
@supapower/vue	Vue composables for Supapower: PGlite live queries plus sync status

Examples

Example	Description
chat	A terminal chat app, showing a two-way sync between Supabase and PGlite
vue-chat	A browser chat app, showing @supapower/worker's multi-tab SharedWorker and a two-way sync between Supabase and PGlite

Requirements

• Bun 1.4 or later, used as package manager, test runner and script runner
• Node.js 22 or later or a modern browser for consumers of the published packages

Getting started

bun install
bun run check

bun run check runs the same four steps as continuous integration: lint, format check, typecheck and tests.

Scripts

Script	What it does
bun run build	Compiles every package to dist with the TypeScript compiler
bun run typecheck	Typechecks every package, tests included
bun test	Runs the test suite with the Bun test runner
bun run test:coverage	Runs the test suite and reports coverage
bun run lint	Lints with Oxlint
bun run lint:fix	Lints and applies the fixes Oxlint can make safely
bun run format	Formats the repository with Oxfmt
bun run format:check	Fails when a file is not formatted
bun run changeset	Describes a change so it can be released
bun run clean	Removes build output

Toolchain

Everything is ESM and TypeScript. There is no CommonJS output and no bundler in the build.

• Bun for dependency installation, workspaces, scripts and tests
• TypeScript 7 for typechecking and for emitting JavaScript and declarations
• Oxlint and Oxfmt for linting and formatting
• Husky and lint-staged to lint and format staged files on every commit
• Changesets for versioning and publishing

License

Apache-2.0, Copyright 2026 Aboviq AB.