Retool App Builder

Build importable Retool apps using ToolScript/RSX — Retool's markup language for source-controlled apps.

A. Orientation

This skill creates importable Retool apps. Each app is a directory containing RSX markup files, position layout JSON, and metadata — zipped for Retool import.

Reference files (paths relative to this skill):

• references/TOOLSCRIPT-CHEATSHEET.md — READ FIRST. Condensed rules for component nesting, positioning, IDs, queries, events.
• references/TOOLSCRIPT-SPEC.md — Full 2500-line spec. Use for deep lookups when the cheatsheet isn't enough.
• assets/examples/ — 8 importable template apps (Minimal, CRUD Table, Master-Detail, Search Filter, AI Chat, Advanced CRUD, Charts Dashboard, API Dashboard).

Scripts in scripts/ handle validation, scaffolding, and position math — use them instead of manual RSX editing whenever possible.

Output contract: ALWAYS produce a named directory with all required files (main.rsx, functions.rsx, metadata.json, .positions.json) AND a zip via zip_app.sh.

B. Scripts Reference

Principle: Prefer scripts over manual RSX editing. Scripts handle position math, ID generation, and file consistency automatically. Only edit RSX directly for complex customizations scripts can't handle (custom attribute values, conditional logic, complex nesting).

C. Task Identification

Determine the mode based on what the user asks:

• NEW — "build me a retool app for..." → scaffold_app.py with closest template → customize → validate → zip
• EDIT — "add X to my retool app" / "change Y in this app" → list_components.py first → targeted changes → validate → zip
• IMPROVE — "make this app production-ready" / "review my app" → list_components.py → audit → apply changes → validate → zip

D. Template Selection Matrix

For NEW apps, pick the closest template:

Read the template example files from assets/examples/<name>/ before customizing — understand what you're starting from.

E. NEW App Workflow

1. Read references/TOOLSCRIPT-CHEATSHEET.md for rules
2. Scaffold:

   python scripts/scaffold_app.py "App Name" --template <type> --output-dir <path>
   

3. Note: Scaffolded apps include mock data fallbacks and a Setup Guide modal so the app is functional on import without a database. See "Mock Data" below.
4. Read ALL generated files to understand the starting point
5. Read the closest example from assets/examples/ for pattern reference
6. Customize: modify query SQL, component labels/attributes, column definitions, form fields
7. Add new components:

   python scripts/add_component.py <dir> --type TextInput --id searchInput --parent-frame '$main' --after pageTitle --attrs 'label="" placeholder="Search..."' --width 6
   

8. Add new queries:

   python scripts/add_query.py <dir> --type SELECT --id selectItems --table items --sql-file
   

9. Extract if main.rsx is large:

   python scripts/extract_component.py <dir> --component editModal
   

10. Fix positions if needed:

    python scripts/fix_positions.py <dir>
    

11. Validate:

    python scripts/validate_app.py <dir>
    

    Fix ALL failures before proceeding.
12. Zip:

    bash scripts/zip_app.sh <dir>
    

F. EDIT Workflow

1. Understand the app:

   python scripts/list_components.py <dir>
   

2. Read specific files that need changes
3. Make targeted modifications using scripts where possible:
   • Adding components → add_component.py
   • Adding queries → add_query.py
   • Extracting to src/ → extract_component.py
4. For complex changes (modifying existing attributes, rewiring events), edit RSX directly
5. Fix positions:

   python scripts/fix_positions.py <dir>
   

6. Validate:

   python scripts/validate_app.py <dir>
   

7. Zip:

   bash scripts/zip_app.sh <dir>
   

G. IMPROVE Workflow + Audit Checklist

1. Understand the app:

   python scripts/list_components.py <dir>
   

2. Read functions.rsx fully to understand query patterns
3. Audit against checklist:
   • Destructive queries (DELETE) have requireConfirmation={true}?
   • Mutation queries have success events that refresh data?
   • After update: does it re-select the updated row (selectRow)?
   • After delete: does it clear selection (clearSelection)?
   • Forms have loading="{{ query.isFetching }}" and disableSubmit="{{ query.isFetching }}"?
   • Could dropdown options use SqlTransformQuery instead of separate queries?
   • Could filtering use client-side setFilterStack() instead of SQL WHERE?
   • Are State variables used for UI mode flags (bulk update, editing state)?
   • Does the app have proper event chains (mutate → refresh → UI update)?
   • Are ModalFrame/SplitPaneFrame/DrawerFrame/SidebarFrame children of App (not Frame)?
   • PlotlyChart data/layout stored in lib/ JSON files (not inline)?
   • HTML/IFrame components sanitize user-provided content?
   • Remove mock data fallbacks if real DB is connected (Array.isArray(q.data) ? q.data : [...] in Table/Select data attributes)?
   • Remove Setup Guide modal if no longer needed?
4. Present findings and proposed changes to user
5. Apply approved improvements
6. Validate + zip

H. Manual Editing Reference

For when scripts aren't sufficient — the critical rules to follow:

Nesting

• ModalFrame/SplitPaneFrame/DrawerFrame must be children of <App> (not <Frame>)
• Form requires <Header> + <Body> + <Footer> (all three; use showHeader={false} to hide)
• Container requires at least one <View> direct child (not inside Body)
• Table requires at least one <Column> child
• Never use enableFullBleed={true} on Containers inside SplitPaneFrame/DrawerFrame — causes overflow

Positioning

• Every visible component needs a .positions.json entry
• Omit row and col when they are 0 (zero is the default)
• View is transparent — no position entry ever
• col + width <= 12
• Children inside a View use container: parentContainerId + subcontainer: viewId
• Header/footer items use rowGroup: "header" or rowGroup: "footer"
• ModalFrame children use subcontainer: modalId

Toolbar Layout

When placing buttons alongside filter inputs (Select, DateRange, TextInput), buttons need special sizing to look right:

• Add heightType="auto" to the Button RSX
• In positions: use height: 0.8 (not 1.0) and offset row by +0.2 from the filter row
• Ordering: filters → search → action buttons (left to right)
• Extract ModalFrame components (especially Setup Guide) to src/ files via Include

IDs

• All IDs globally unique across all .rsx files
• Columns/Views/Options/Actions: 5-char hex [0-9a-f]{5}
• Events: 8-char hex [0-9a-f]{8}

Syntax

• No <!-- comments --> — use _comment="text" attribute
• Boolean: {true} not "true"
• Expressions: {{ widget.value }}
• Include: {include("./lib/file.sql", "string")}
• All SQL goes in lib/ files — even one-liners. Never use inline query="SELECT ...".

Attributes to Omit

Don't include these — Retool strips them and they clutter the output:

• resourceDisplayName on any query (cosmetic label, not used for import)
• transformer="return data" on SELECT queries (it's the default)
• resourceDisplayName="JavascriptQuery" and runWhenModelUpdates={false} on JavascriptQuery
• query="" on RESTQuery (empty string is the default)
• hidden={false}, showFooter={false} on any component (false is always the default)

Mock Data

Scaffolded apps (crud, master-detail, search-filter, advanced-crud) include inline mock data fallbacks on Table and Select data attributes. This makes the app fully functional with sample data before a real database is connected.

How it works: data="{{ Array.isArray(query.data) ? query.data : [{ id: 1, name: 'Example' }] }}" — when the query has no resource, query.data returns an error object (not an array), so the fallback is used. When a real DB returns data (an array), the ternary uses it directly.

To connect your real database:

1. Update resourceName in each query in functions.rsx to your database resource UUID
2. Remove the mock data fallbacks from Table/Select data attributes (change {{ Array.isArray(query.data) ? query.data : [...] }} to {{ query.data }})
3. Delete the Setup Guide modal (setupGuideModal ModalFrame) and the setupGuideBtn button

For deeper reference: read references/TOOLSCRIPT-CHEATSHEET.md or the full spec.

I. Quick Templates

main.rsx skeleton

<App>
  <Include src="./functions.rsx" />
  <Frame id="$main" type="main" padding="8px 12px" paddingType="normal" sticky={false}
    isHiddenOnDesktop={false} isHiddenOnMobile={false}>
    <Text id="pageTitle" value="### App Title" verticalAlign="center" marginType="normal" />
  </Frame>
</App>

functions.rsx skeleton

<GlobalFunctions>
</GlobalFunctions>

metadata.json template

{
  "toolscriptVersion": "1.0.0",
  "version": "43.0.9",
  "pageUuid": "00000000-0000-0000-0000-000000000001",
  "appTemplate": {
    "appMaxWidth": "100%",
    "appThemeId": -1,
    "experimentalFeatures": { "object": { "sourceControlTemplateDehydration": false } },
    "notificationsSettings": { "object": { "globalQueryShowFailureToast": true, "globalQueryShowSuccessToast": true, "globalQueryToastDuration": 4.5 } },
    "version": "3.338.0"
  }
}

.positions.json minimal

{
  "pageTitle": { "row": 0, "height": 0.6, "width": 12 }
}

Event template

<Event id="hex8char" event="success" method="trigger"
  params={{ ordered: [] }} pluginId="queryId" type="datasource"
  waitMs="0" waitType="debounce" />

SELECT query one-liner

<SqlQueryUnified id="selectItems" query={include("./lib/selectItems.sql", "string")}
  resourceName="REPLACE_WITH_RESOURCE_UUID"
  resourceTypeOverride="" warningCodes={[]} />

INSERT one-liner

<SqlQueryUnified id="insertItem" actionType="INSERT" changesetIsObject={true}
  changesetObject="{{ { ...CreateForm.data } }}" editorMode="gui"
  resourceName="REPLACE_WITH_RESOURCE_UUID"
  resourceTypeOverride="" runWhenModelUpdates={false} tableName="public.items">
  <Event id="hex8" event="success" method="trigger" pluginId="selectItems" type="datasource" waitMs="0" waitType="debounce" />
</SqlQueryUnified>

UPDATE_BY one-liner

<SqlQueryUnified id="updateItem" actionType="UPDATE_BY" changesetIsObject={true}
  changesetObject="{{ { ...EditForm.data } }}" editorMode="gui"
  filterBy={
    '[{"key":"id","value":"{{ table.selectedRow.id }}","operation":"="}]'
  }
  resourceName="REPLACE_WITH_RESOURCE_UUID"
  resourceTypeOverride="" runWhenModelUpdates={false} tableName="public.items" />

DELETE_BY one-liner

<SqlQueryUnified id="deleteItem" actionType="DELETE_BY" editorMode="gui"
  filterBy={
    '[{"key":"id","value":"{{ table.selectedRow.id }}","operation":"="}]'
  }
  requireConfirmation={true} confirmationMessage="Delete **{{ table.selectedRow.name }}**?"
  resourceName="REPLACE_WITH_RESOURCE_UUID"
  resourceTypeOverride="" runWhenModelUpdates={false} tableName="public.items" />