The runtime library

Generated code runs on elasticore-springboot3 (Spring Boot 3) or elasticore-springboot4 (Spring Boot 4). Both use the Java package io.elasticore.springboot3, so generated imports do not change between Boot versions. Upgrade it together with the generator - the same version: generated code uses runtime classes that older runtimes do not have.

Who is asking

Class or field	What
security.CurrentUser - currentUser.id(), signedIn(), hasRole("ADMIN")	who is asking, as the generated services see it; the default is SessionCurrentUser, a bean of yours replaces it (Spring Security)
CurrentUser.runAsSystem(() -> ...)	the application itself: every @access check passes inside it - start-up data, a nightly job
ACCESS.require(currentUser, "report")	fields of the generated service: the entity's @access for an operation of your own - 401 for a visitor, 403 for who may not; an operation the line does not name is the administrator's
security.SessionCurrentUser.signIn(request, id, role), signOut(request)	the session the generated sign-in uses - for a flow of your own (sign up and sign in at once)
security.AccessPolicy, security.PasswordHasher	beans you may replace (PBKDF2 is the default hasher)

// the application itself creating an administrator at start-up
CurrentUser.runAsSystem(() -> customers.save(admin));

Value types

Class	What
domain.Money	the type of a money field. Money.of("10.00"), Money.of(bigDecimal) (null for null), plus, minus, times(long), times(Quantity), times(BigDecimal), rounded(2) (half-up), toBigDecimal(), isNegative(), compareTo. plus(null) / minus(null) return the same amount. Immutable; 10 and 10.00 are equal
domain.Quantity	the type of a quantity field: never negative; minus below zero answers 422 not enough; plus, covers

A 5.5 % VAT: net.times(new java.math.BigDecimal("0.055")).rounded(2).

Refusals

Exception (io.elasticore.springboot3.)	Answer
validation.BadRequestException	400
security.NotSignedInException	401
security.ForbiddenException	403
validation.NotFoundException (or jakarta.persistence.EntityNotFoundException)	404
validation.ConflictException	409
validation.InvariantViolationException	state. codes 409, reference. 404, others 422
http.PortCallException	502

Each takes (code, message, args...) to be translated; see API and error answers.

Plumbing you may meet

Class	What
EnableElastiCore	registers the port proxies (HTTP runtime mode, DBMS)
validation.RequestShapeErrors	the problem+json answers before a controller - imported by the generated XxxApiErrors
validation.ErrorMessages, BeanValidation	the message lookup in the request's language, service-side validation
util.IdUtils.newId(n)	the @genid id generator
entity.PersistentModel	the marker for mapping: xml domain classes (Kotlin all-open / no-arg)
domain.Lookup	what derive(lookup) reads referenced rows with