powersync-selfhost

Self-hosted PowerSync stack for Cold Code Labs (deployed on the surtr node via Coolify).

Sync engine + Postgres bucket storage, no MongoDB. Demonstrates the full pipeline: Postgres → logical replication → PowerSync buckets → authenticated client sync.

Services

Service	Role	Public
pg-db	Source Postgres (wal_level=logical), sample lists/todos + publication	no
pg-storage	Postgres bucket storage for PowerSync	no
pg-init	One-shot idempotent seed (tables + publication + sample rows)	no
powersync	PowerSync Service (engine), port 8080	yes (http://powersync.coldcodelabs.com)

Configuration

Config is passed to the engine as base64 env vars (no file mounts):

• SVC_B64 — base64 of the PowerSync service config (replication, storage, static JWKS client_auth)
• SYNC_B64 — base64 of the sync rules (lists, todos)
• SEED_B64 — base64 of the seed SQL
• PGPW — Postgres password (internal network only)

All set as Coolify env vars; nothing secret lives in this repo.

Auth

Client auth uses a static RSA JWKS embedded in the service config. Dev JWTs (max 24h per PowerSync) are minted off-repo with the matching private key.

UI

The engine has no admin UI. Navigate sync state with the PowerSync Diagnostics App (hosted at https://diagnostics-app.powersync.com or the journeyapps/powersync-diagnostics-app image): enter the engine endpoint + a dev JWT to inspect buckets, sync rules, stats and run SQL.