Crouton Generation Reference

The drift-corrected lookup tables for the generation domain: what a schema file is, what one generate run produces, and exactly how everything is named. Every command/path/line here was verified against the repo on 2026-07-02; where the shipped docs are wrong, this file says so explicitly.

When to use / when NOT to use

You need	Go to
The generate workflow (gather fields → config → schema-review gate → generate → post-gen steps), MCP tool workflow, worked examples	crouton skill (.claude/skills/crouton.md) — defer to it; this file is the lookup pack under it
Human sign-off on a data model before generating	schema-review skill (#314)
Migration mechanics, the .nuxt/hub/db/schema.mjs build-first gotcha (#523), package-owned tables	db-migrations skill
Why the system is shaped this way (two-halves rule, invariants, registries)	sibling crouton-architecture-contract
Layout engine theory (LayoutTree, viability math, placer internals)	sibling crouton-layout-reference — §6 here covers only the generate→seed handoff
Booting/seeding a running app, inspecting the DB	sibling crouton-run-and-operate
Field-meta long-form descriptions, pagination/FK-filter details, crouton add/init/db-pull	packages/crouton-cli/CLAUDE.md (owns them; §9 lists its known-stale spots)

Vocabulary (crouton terms, defined once)

• Collection — one CRUD entity (e.g. products): a generated, self-contained nested Nuxt layer with form, list, composable, team-scoped API, Drizzle schema. Always team-scoped (every row has teamId).
• Layer — here: the domain folder layers/<layer>/ grouping collections (e.g. shop). (Distinct from Nuxt-layer-as-package; see crouton-architecture-contract.)
• fieldsFile — the JSON file defining a collection's fields (§1). The input to everything.
• crouton.config.js — unified config at the app root: collections + targets + dialect for the CLI, features flags for the @fyit/crouton module. Full key reference: packages/crouton-cli/CLAUDE.md "Config File Format".
• Manifest (crouton.manifest.ts) — per-package declaration of field types, reserved names, detection patterns. The source of truth for field types (§2).
• The CLI — packages/crouton-cli, bins crouton (= crouton-generate) and crouton-seed (verified package.json bin map). In an app with @fyit/crouton-cli as devDep: pnpm exec crouton <cmd>.

1. fieldsFile JSON format

Shape (each top-level key is a field name):

{
  "id":         { "type": "string",  "meta": { "primaryKey": true } },
  "name":       { "type": "string",  "meta": { "required": true, "maxLength": 255, "translatable": true } },
  "price":      { "type": "decimal", "meta": { "precision": 10, "scale": 2 } },
  "categoryId": { "type": "string",  "refTarget": "categories" },
  "authorId":   { "type": "string",  "refTarget": "users", "refScope": "adapter" }
}

Per-field keys: type (§2), meta (below), refTarget (name of the referenced collection — generates a CroutonFormReferenceSelect in the form, an FK query-param filter on the list endpoint, and cache auto-refresh), refScope ('adapter'/'external' for refs outside the generated layers, e.g. users; handled in lib/generators/{form-component,list-component,database-queries}.ts).

meta keys are owned by packages/crouton-cli/CLAUDE.md "Field Meta Properties" — read the full catalog there. What that doc doesn't say (verified behaviour):

meta key	Non-obvious verified behaviour
nullable	.nullish() instead of .optional() in Zod; json and date types get .nullish() automatically (generate-collection.ts)
translatable	value lives in the collection's translations JSON column; root column is a cache/fallback — see trap below
component	besides overriding the form control, it triggers that package's generator contribution via manifest detects, even without a feature flag

Trap — translatable fields must be required: false. The real value lives in translations.{locale}.field; a NOT NULL root column fails inserts that only populate translations. (crouton-cli/CLAUDE.md "Why this matters".)

Three ways a field becomes translatable (merged, in this priority — verified generate-collection.ts:678-735): field-level meta.translatable: true → collection-level translatable: true in config (auto-detects common names: name, title, description, label, content, … on string/text fields) → config-level translations.collections.{plural}: [fields].

Never declare (auto-generated on every collection): id, teamId, owner, createdAt, updatedAt, createdBy, updatedBy; hierarchy adds parentId, path, depth, order. Reserved field names additionally include optimisticId, optimisticAction (verified packages/crouton-core/crouton.manifest.ts:27-37). Reserved collection names: api, server, app, pages, components, composables, layouts, middleware, plugins, assets, public, node_modules (same file, :39-43).

2. Field-type catalog

Source of truth is per-package manifests, not any doc table. getTypeMapping() in packages/crouton-cli/lib/utils/manifest-loader.ts (~:297) builds the map from every crouton.manifest.ts; core's types live in packages/crouton-core/crouton.manifest.ts:12-25. The tables in crouton-cli/CLAUDE.md and crouton-mcp/CLAUDE.md are copies (the MCP one is explicitly a fallback used only when manifest loading fails — packages/crouton-mcp/src/utils/field-types.ts).

Verified from the core manifest + the SQLite branch of lib/generators/database-schema.ts:89-100:

Type	SQLite column (actual)	Zod	TS	Default	Form component	Aliases
string	text()	z.string()	string	''	UInput
text	text()	z.string()	string	''	UTextarea
number	integer()	z.number()	number	0	UInputNumber	integer
decimal	real()	z.number()	number	0	UInputNumber
boolean	integer({ mode: 'boolean' })	z.boolean()	boolean	false	UCheckbox
date	integer({ mode: 'timestamp' })	z.date()	Date | null	null	CroutonCalendar	datetime
json	jsonColumn()	z.record(z.string(), z.any())	Record<string, any>	{}	UTextarea
repeater	jsonColumn()	z.array(z.any()) (typed when meta.properties)	any[]	[]	CroutonFormRepeater
array	text()	z.array(z.string())	string[]	[]	UTextarea
reference	text()	z.string()	string	''	CroutonFormReferenceSelect
image	text()	z.string()	string	''	CroutonImageUpload → assets picker¹
file	text()	z.string()	string	''	CroutonImageUpload → assets picker¹

¹ crouton-assets' manifest declares detects: { fieldTypes: ['image','file'], refTargetPatterns: ['asset','file','image','media'] } (verified packages/crouton-assets/crouton.manifest.ts), so its generator contribution swaps in CroutonAssetsPicker (crop for image) whenever those fields appear — no feature flag needed.

Notes:

• reference exists as a first-class type, but in practice relationships are written as type: "string" + refTarget — the user-facing table in the crouton skill omits reference for that reason.
• Alias resolution (#285): loadFields resolves aliases to their canonical type before any generator runs (each mapping entry carries canonical — manifest-loader.ts:303-318). History: datetime once leaked through unresolved → a raw <UInput> + a text column. Rules of thumb: number = integer column; decimal = float/real; a string-encoded enum ('0'/'1'/'2') is string, not number.
• Adding a field type = a manifest change (plus generator branches) — see crouton-cli/CLAUDE.md "Add a new field type".

3. Dialect defaults — split by entry point

Code truth (the docs were corrected to match in the #1073 reshape):

Entry point	Dialect default	Where
crouton <layer> <collection> (direct generate)	sqlite	bin/crouton-generate.js
crouton init <name>	sqlite	bin/crouton-generate.js
crouton config	the config file's dialect; if the config omits it → 'pg'	lib/generate-collection.ts (the config subcommand has no --dialect flag at all)

Rule: always write dialect: 'sqlite' explicitly in crouton.config.js (every in-repo app targets D1/SQLite) — the silent pg fallback on the config path is the trap.

4. Naming contract

Everything derives from toCase() (lib/utils/helpers.ts — real English pluralization via the pluralize npm package + scule casing; categories↔category works, naive +s does not apply). Given collection products in layer shop:

Artifact	Name	Derivation
Directory	layers/shop/collections/products/	layer + lowercase plural
API base	/api/teams/[id]/shop-products/	{layer}-{plural}
Patch/delete route files	[productId].patch.ts, [productId].delete.ts	[{singularCamel}Id] — NOT [id] (docs say [id]; code is generate-collection.ts:932-937, fixture confirms [itemId].patch.ts)
Components	ShopProductsForm, ShopProductsList	the collection's own nuxt.config.ts registers app/components with prefix: 'ShopProducts', global: true
Composable	useShopProducts (file useShopProducts.ts)	use{LayerPascal}{PluralPascal}
Registry key in croutonCollections	shopProducts (+ import shopProductsConfig)	{layerCamel}{PluralPascal} (generate-collection.ts:1121-1122; mirrored by compose-layout.ts registryKeyFor())
Drizzle schema export	shopProducts	same
DB table	shop_products	toSnakeCase(\${layer}_${plural}`) (database-schema.ts:171; confirmed by a real seed.json's "table": "bookings_locations"`)
Test files	ShopProducts.test.ts, ShopProducts.api.test.ts	{LayerPascal}{PluralPascal}

System-collection exception: a layer named crouton-* gets API path crouton-<collection-kebab> instead of {layer}-{plural} (generate-collection.ts:882-888) — e.g. layer crouton-events + collectionEvents → /api/teams/[id]/crouton-collection-events/. Its table is toSnakeCase('crouton' + Collection) (database-schema.ts:168).

5. Exact artifact list of one generate run

Verified against writeScaffold (lib/generate-collection.ts:880-1155) and on-disk generated collections (fixtures/minimal/layers/main/collections/items/, pocs/booking-demo/layers/bookings/collections/*/).

Per collection, under layers/{layer}/collections/{plural}/:

app/components/_Form.vue            # NOTE THE UNDERSCORE — see below. Skipped when
                                    #   formComponent is set (config or auto-detected)
app/components/List.vue
app/components/{FieldPascal}/{Input,Select,CardMini}.vue   # one dir per repeater field
app/composables/use{Layer}{Plurals}.ts   # Zod schema + columns + collection config
server/api/teams/[id]/{layer}-{plural}/
    index.get.ts  index.post.ts  [{singular}Id].patch.ts  [{singular}Id].delete.ts
    [{singular}Id]/move.patch.ts + reorder.patch.ts   # hierarchy only
    reorder.patch.ts                                  # sortable (non-hierarchy) only
server/database/schema.ts           # Drizzle (+ translations JSON column when translatable)
server/database/queries.ts          # getAll* with FK-filter + opt-in pagination overloads
server/database/seed.ts             # only with seed flag (drizzle-seed + Faker)
seed.json                           # always, except hierarchy collections (#298) — editable sample rows
{Layer}{Plurals}.test.ts            # Zod schema-smoke (#785) — skipped by --no-tests / tests:false
{Layer}{Plurals}.api.test.ts        # mocked route-handler test (#791), carries // @ts-nocheck — same gate
types.ts   nuxt.config.ts   README.md

The _Form.vue underscore: the actual filename is _Form.vue (generate-collection.ts:912) even though the dry-run output prints Form.vue (:825) and both the crouton skill and crouton-cli/CLAUDE.md draw Form.vue. It still registers as {Layer}{Plurals}Form — the composable's componentName field carries the name (verified fixtures/minimal/.../useMainItems.ts:44: componentName: 'MainItemsForm').

Side effects beyond the collection dir (config-mode run, same file :1091-1152 + runPostGeneration :1165-1293):

Surface	What happens
layers/{layer}/nuxt.config.ts	created/updated to extend the collection
root nuxt.config.ts	./layers/{layer} added to extends; enabled feature packages synced in
app/app.config.ts	collection upserted into croutonCollections (import + entry)
i18n locale JSON	created when the collection has translatable fields
server/database/schema/index.ts	named schema export added per collection (config mode automates the "manual export" step the crouton skill lists)
migration	drizzle-kit runs directly on the resolved schema graph — no Nuxt build (#1445 WS2). ~2s. On a cold scaffold it soft-defers (↻ Migration deferred … re-run: pnpm db:generate, exit 0) rather than producing it in the same run — #1457. The old npx nuxt db generate 30s-timeout/silent-zero-migrations failure (#523) is retired by design on resolver apps; still possible on an external legacy .nuxt-bundle scaffold (no app in this repo since #1456) → db-migrations skill
CSS	Tailwind @source directive ensured
.nuxt-adjacent registries	type registry + server/utils/crouton-query-registry.ts (lazy per-collection query lookup)
crouton.layout.json (app root)	deterministic default layout (§6)
devtools	generation recorded for the DevTools Generators tab

Real-world caveat: apps generated before #298/#709 (e.g. apps/velo, fixtures/*) lack seed.json-era artifacts at root (crouton.layout.json, query registry) — absence there is history, not a bug. pocs/booking-demo is a current-pipeline example with all of them.

6. Seed + default-layout pipeline (generate → booted app)

Mechanics of crouton-seed (discovery/topo-sort/wrangler transport) are owned by packages/crouton-cli/CLAUDE.md "App Seeding" — current and accurate. What this reference adds, verified from code:

1. Layout pass (#709) — runPostGeneration → lib/compose-layout.ts writeDefaultLayout() calls composeDefaultLayout from @fyit/crouton-layout/app/utils/layout-compose (a stale comment at the top of compose-layout.ts still says "from crouton-core"; the import at :16 is truth — it moved in #751) and writes crouton.layout.json: { id: 'default', renderer, pattern, viable, tree }. Patterns: calendar-primary | master-detail | form-centric | stacked | empty (verified layout-compose.ts:54). Theory → sibling crouton-layout-reference.
   • Drift hazard (declared in code, compose-layout.ts:22-26): the CLI has no live app.config at generate time, so it hardcodes mirror copies of the block sizing contracts (CORE_BLOCKS/BOOKINGS_BLOCKS). Changing a minWidth/defaultSize in crouton-layout/crouton-bookings app.config must be mirrored here — the hazard and the current values are owned by sibling crouton-layout-reference §6.
2. Package seed providers — crouton-seed --db <name> [--remote|--dry-run] collects each package's <pkg>/seed provider into idempotent upsert SQL, executed via wrangler d1 execute.
3. Collection fixtures — each layers/*/collections/*/seed.json ({ table, key, rows } — verified shape in pocs/booking-demo) is upserted with injected system columns + stable seedId(layer, collection, key) ids (lib/seed-app.ts:180-193).
4. Layout row — collectDefaultLayoutSql (seed-app.ts:213-242) upserts the tree into layout_configs row id default — the row the team layout page loads. NB (code comment): layout_configs.id is a global PK, so this seeds one default layout for the single seeded team only.

Result: a fresh POC boots laid out, not blank. The layout is data (editable in CroutonLayout), never generated .vue.

7. Deterministic vs AI-assisted

Deterministic (no LLM anywhere)	AI-assisted (the agent is the intelligence)
All template generation (the 16 generators in lib/generators/ are string templates keyed off the schema)	Schema design — the AI writes the fieldsFile; MCP design_schema/init_schema only feed it reference material
Type/alias resolution; Zod/TS/Drizzle mapping (manifest-driven)	The human schema-review gate (#314) on top of machine validation
MCP validate_schema (pure structural check), dry_run, rollback	Optional runtime AI features (crouton-ai translate, alt-text) — not part of generation
The default-layout pass — "No LLM" is stated in compose-layout.ts's own header; the LLM /layout pass (#711) is gated and out of scope	Layout iteration via the agent⇄human ticket loop (sanitizer keeps ingest deterministic)
Seeding (SQL assembly, stable ids, topo-sort; Faker field-name heuristics are heuristic, not AI)
Generated tests (samples derived from each field's Zod; no Date.now()/Math.random())

Practical consequence: generation output is reproducible and diff-reviewable; the only judgment calls are the schema itself and any post-hoc layout edits — which is exactly where the sign-off gates sit.

8. Rollback & regeneration semantics

Rollback (crouton rollback <layer> <collection> [--dry-run] [--keep-files] [--force]) — verified lib/rollback-collection.ts:252-300, five steps:

1. delete layers/{layer}/collections/{plural}/ (skipped by --keep-files)
2. remove the schema export from server/database/schema/index.ts
3. remove the croutonCollections entry + import from app.config.ts
4. remove the collection from the layer root nuxt.config.ts
5. remove ./layers/{layer} from the root nuxt.config.ts only if no other collections remain in the layer

Also: crouton rollback-bulk --layer=<layer> / --config=<path> (whole layer / everything in a config) and crouton rollback-interactive (selection UI). The MCP rollback tool defaults dryRun: true (verified crouton-mcp/src/tools/rollback.ts:7); the CLI's does not — pass --dry-run yourself first.

Rollback does NOT touch the database: no migration is reverted, no table dropped, no rows deleted. Clean those up separately (a follow-up migration, or accept the orphan table on throwaway POCs).

Regeneration: re-running crouton config / crouton <layer> <collection> overwrites every generated file unconditionally — writeScaffold has no file-existence guard (fsp.writeFile loop at generate-collection.ts:1074-1078; code-derived, not reproduced end-to-end). Two consequences:

• The generated file headers saying "regeneration requires --force flag" are stale; --force actually means (a) proceed despite missing package dependencies (:747-754) and (b) override schema-index export conflicts (:373-384).
• Hand edits inside generated files are lost on regeneration — including the "editable" seed.json (it is in the unconditional write list, :1042-1049). Edit seed.json only if you won't regenerate, or re-apply edits after. If you customize a Form, prefer formComponent: (skips _Form.vue generation entirely) over editing the generated one.

9. Doc drift in this domain

The 2026-07-02 sweep's corrections (docs paths, docs-MCP tool names, dead nuxt-crouton-* package paths, the --dialect default, _Form.vue/[{singular}Id].patch.ts filenames, the sync-script extension, the manifest-vs-fallback field-type source) were applied to the canonical docs in the #1073 reshape — .claude/skills/crouton.md, packages/crouton-cli/CLAUDE.md, packages/crouton-mcp/CLAUDE.md now match the code. Don't trust this skill over them; if they disagree again, code wins (trust order: sibling crouton-docs-trust-map §1) and the fix goes to the canonical doc via the sync-docs workflow, not to a table here.

One known drift remains in code, not docs: generated file headers still claim "regeneration requires --force" while regeneration actually overwrites unconditionally (§8) — that's a template fix in packages/crouton-cli/lib/generators/, not a doc edit.

Provenance and maintenance

verified: 2026-07-02

Facts verified against: packages/crouton-cli/{bin/crouton-generate.js, lib/generate-collection.ts, lib/compose-layout.ts, lib/seed-app.ts, lib/rollback-collection.ts, lib/utils/{helpers.ts,manifest-loader.ts}, lib/generators/database-schema.ts, package.json}, packages/crouton-core/crouton.manifest.ts, packages/crouton-assets/crouton.manifest.ts, packages/crouton-layout/app/utils/layout-compose.ts, packages/crouton-mcp/src/{index.ts,tools/rollback.ts}, and on-disk generated output in fixtures/minimal/ + pocs/booking-demo/. Line numbers are anchors from that date and will drift — trust the symbol names over the :NNN. Issue numbers (#285, #298, #523, #558, #709, #711, #751, #785, #791) are cited from code comments and discovery-report summaries; check the issue if load-bearing.

Re-verification one-liners:

# dialect defaults (expect sqlite in bin, || 'pg' in runConfig)
grep -n "dialect" packages/crouton-cli/bin/crouton-generate.js | head -5
grep -n "config.dialect ||" packages/crouton-cli/lib/generate-collection.ts
# field-type catalog + aliases (the source of truth)
sed -n '12,25p' packages/crouton-core/crouton.manifest.ts
# artifact list / filenames (underscore Form, [xId] routes)
grep -n "_Form.vue\|Id].patch" packages/crouton-cli/lib/generate-collection.ts | head -5
# naming (registry key, table name)
grep -n "registryKeyFor\|snakeCaseTableName" packages/crouton-cli/lib/{compose-layout.ts,generators/database-schema.ts}
# layout payload + seed row id
grep -n "id: 'default'\|layout_configs" packages/crouton-cli/lib/{compose-layout.ts,seed-app.ts}
# CLI/manifest/skill field-type sync check
node scripts/validate-field-types-sync.mjs