PowerSync
Local-first database sync service that syncs data from Postgres (and MongoDB, MySQL in beta) to local SQLite on mobile and web clients. Uses 'sync rules' (YAML-based) to define what data each user sees. Optimized for mobile apps with offline-first requirements.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
JWT-based auth with per-user sync rule scoping provides row-level security at the sync layer. SOC 2 Type II. Data never leaves the PowerSync server without JWT authorization.
⚡ Reliability
Best When
You're building mobile or edge agent applications that need offline-first SQLite with automatic sync to Postgres/MongoDB and fine-grained per-user data partitioning.
Avoid When
You don't need mobile/offline capability or per-user data isolation — direct database connections are simpler.
Use Cases
- • Sync a user-specific data partition to agent local SQLite for personalized, offline-capable agent workflows
- • Build mobile agent applications where agents run locally on iOS/Android with full SQLite access even without connectivity
- • Implement fine-grained data partitioning via PowerSync sync rules so each agent instance sees only its authorized data
- • Use PowerSync's conflict resolution model for multi-device agent deployments where multiple agents write to shared state
- • Progressive web app (PWA) agent deployments with IndexedDB-backed SQLite via PowerSync's web SDK
Not For
- • Server-side-only workloads where all data processing happens on the backend
- • Use cases requiring strong consistency — PowerSync provides eventual consistency via sync
- • Complex multi-table transactional writes — local writes are queued and applied asynchronously
Interface
Authentication
Clients authenticate using JWTs issued by your backend (Supabase, Auth0, custom). PowerSync validates the JWT to determine which sync rules apply to the client. Per-user data partitioning is defined in sync rules YAML using JWT claims.
Pricing
Open source server available for self-hosting. PowerSync Cloud is the managed service. Pricing scales with number of connected clients and sync operation volume.
Agent Metadata
Known Gotchas
- ⚠ Sync rules are defined in YAML and must be deployed to the PowerSync service — agents cannot modify sync rules at runtime; they require a service restart
- ⚠ Local SQLite writes are placed in an upload queue — agents must not assume immediate consistency with the backend; uploads can be delayed on poor connectivity
- ⚠ Sync rules use parameterized queries based on JWT claims — agents must ensure their JWT includes all claims referenced in sync rules or data will not sync
- ⚠ Initial sync downloads all data matching the agent's sync rules — agents with broad sync rules may experience significant initial load time on first connection
- ⚠ PowerSync uses its own conflict resolution (last-write-wins by default) — agents implementing custom conflict resolution must use the SDK's write hooks
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for PowerSync.
Scores are editorial opinions as of 2026-03-06.