entity-store

PostgreSQL Entity Store example

This shared setup demonstrates the Entity Store pattern in the Go, Java, Python, Rust, and TypeScript examples. One UserProfileFlow owns each profile, while the Dex Server asynchronously projects opted-in Attributes to PostgreSQL.

Start PostgreSQL and Dex

From this directory:

docker compose up -d --wait
dexcli dev --attribute-store-config ./attribute-store.yaml

Compose starts PostgreSQL 17 and creates public.user_profiles on localhost:55432. dexcli dev starts the local Dex environment and loads the Server store named entityStore from attribute-store.yaml.

The same file works with server-zd:

dexcli dev --engine zd --attribute-store-config ./attribute-store.yaml

server-zd also needs the dexzd_attribute_sync_fencing table in each synced database. postgres/init.sql creates it, and the Go Server ignores it. See Fencing table.

Start any one language example according to its README, then create and update a profile through that example's HTTP server:

curl -X POST http://localhost:8080/patterns/entity-store/profile \
  -H 'content-type: application/json' \
  -d '{"userId":"user-42","displayName":"Ada Lovelace","email":"ada@example.com","marketingOptIn":true,"credits":120,"weight":59.5,"lastLoggedInTime":"2026-08-11T15:30:00Z","metadata":{"source":"example","tags":["computing","poetry"]}}'

curl -X POST http://localhost:8080/patterns/entity-store/profile/update \
  -H 'content-type: application/json' \
  -d '{"userId":"user-42","displayName":"Ada Byron","email":"ada.byron@example.com","marketingOptIn":false,"credits":180,"weight":60.25,"lastLoggedInTime":"2026-08-12T09:45:00Z","metadata":{"source":"example","tags":["computing","history"]}}'

All five examples default to port 8080; run one language application at a time or override its HTTP address.

Observe the projection

Projection is asynchronous and latest-state only, so poll PostgreSQL rather than assuming the HTTP response means the SQL row is already visible:

docker compose \
  exec entity-postgres psql -U entity_store -d entity_store \
  -c "SELECT * FROM user_profiles WHERE user_id = 'user-42';"

Clear the synced values with:

curl -X POST 'http://localhost:8080/patterns/entity-store/profile/clear?userId=user-42'

The row remains and its seven projected columns become SQL NULL. A projection failure is logged but never rolls back the authoritative Flow Attribute write.

Stop dexcli with Ctrl+C, then remove PostgreSQL with docker compose down -v.