[SDK 0.0.39] Postgres/Supabase READ patterns fail validation (writes work) — Firestore equivalent works

[DrikaMakerdev]

Bug report: Postgres/Supabase READ patterns fail validation (writes work)

FlutterFlow AI SDK: first observed on 0.0.36 (build 995e259b); retested on 0.0.39
(2026-07-15): identical failure signature, still broken · Dart: 3.12.2 ·
Project: in-sy-sti-vgys6v
Run ID (canonical repro): 2026-07-14T17-04-29-364-ugiya8 (full trace, bundle and replay
workspace in this folder)

Summary

Any DSL pattern that reads Supabase/Postgres rows into page state — and any widget bound
to that state — fails compileDslApp validation. Write actions (PostgresCreate,
PostgresUpdate, PostgresDelete) validate and push fine. This makes it impossible to
author a list/detail screen backed by Supabase from the DSL; users must bind backend queries
manually in the editor.

Minimal repro (40 lines, archived as probe_postgres_state.dart in the bundle)

final t = app.table('probe_items', fields: { ...id + title... });

app.page('ProbePage',
  state: {'items': listOf(t), 'firstTitle': string},
  onLoad: [
    PostgresQuery(t, outputAs: 'itemRows', query: ...),
    SetState('items', ActionOutput('itemRows')),          // ← fails
    PostgresRead(t, outputAs: 'firstRow', query: ...),
    SetState('firstTitle', ActionOutput('firstRow')['title']),  // ← fails
  ],
  body: ... ListView(source: State('items'), itemBuilder: (item) => Text(item['title'])) ...  // ← fails
);

Actual errors (diagnostics from the trace)

• VALIDATION_LOCAL_STATE_UPDATE: Field "items" has an update value that is not properly set
  in Update App State action
• VALIDATION_GENERATOR_VARIABLE: Dynamic children variable not properly configured for ListView
• VALIDATION_PROPERTY_OVERRIDE: Invalid postgres row field operation
• VALIDATION_WIDGET_CLASS_CONFIGURATION: Page has invalid state variable "items": table not found
• VALIDATION_SUPABASE_DATABASE_ACTION: Table not set for Supabase action

Evidence this is an SDK gap, not user error

1. The pattern mirrors the SDK's own shipped reference references/postgres_compile_only_dsl.dart
   (state listOf(table) + PostgresQuery/SetState(ActionOutput) + ListView(source: State))
   — that reference is compile-only and appears to never have been validated against the server.
2. The identical pattern works for Firestore (references/social_feed_data_dsl.dart:
   FirestoreQuery → SetState(ActionOutput) → ListView(source: State(...))), so the gap
   is Postgres-specific lowering of: (a) query outputs into page-state updates, (b) postgres
   row field access (ActionOutput(...)['col']), and (c) generator variables for list widgets.
3. The same errors reproduce with real project tables (typed SDK ff.Tables.* handles) —
   the run at 2026-07-14T17:01:30Z in this project's history shows the exact same
   signature on a real page (CompaniesPage/CompanyDetailPage).
4. Everything else in the same scripts validates: pages, forms, PostgresCreate/Update/Delete
   actions with filters, Navigate, Snackbar.

Expected

PostgresQuery/PostgresRead outputs should be assignable to page state typed as
listOf(<table>) / scalar via ActionOutput(...)[field], and ListView(source: State(...))
over postgres rows should lower to a properly configured generator variable — matching the
Firestore behavior and the shipped Postgres reference.

Impact

Web/admin CRUD screens (list + detail prefill) cannot be authored end-to-end from the DSL for
Supabase-backed projects — a core FlutterFlow + Supabase workflow. Current workaround: author
layout + write actions via DSL, then hand-bind every backend query in the editor.

postgres-read-gap.zip