seam

The medium-neutral editing socket for the schemastud constellation: a widget registry, a form intent bus, a base SchemaForm, and the uniform SelectionChrome primitive — the socket that any skin, dialect, or document model plugs into. (Renamed from @schemastud/rjsf-registry: the old name described one widget flavor riding the socket, not the socket itself.)

Generally-useful additions over react-jsonschema-form — none of which RJSF core has:

• Predicate widget registry — registerWidget(predicateOrKey, widget) resolves widgets by predicate over the schema node instead of RJSF's name-based model; first match wins, later registrations take precedence.
• Form intent bus — createFormIntentBus() is the medium-neutral channel a form emits edit intents on, decoupled from any host transport.
• Uniform SelectionChrome — the grammar-blind selection/presence chrome primitive: it draws the same ring/handle/badge/outline around any skin (rides selectedNodeId, never a document model), so a skin ships zero chrome code. Extracted here from blockdoc so every medium reuses it.
• uiSchema derivation — buildUiSchema(schema, registry) walks a schema and emits an RJSF uiSchema from schema-carried hints (x-widget, x-placeholder), so a form's behavior is declared where its shape is declared.
• Configurable extension-keyword tolerance — createKeywordVocabulary({ keywords, patterns }) declares a host's x-* dialect; createFormValidator() builds an AJV8 validator that never trips strict mode on extension keywords. No vendor dialect is hardcoded.
• Injected $ref fetcher seam — resolveExternalRefs(schema, fetcher) pre-resolves external refs through a host-supplied async fetcher. Transport-agnostic: the host passes its own authed client; this package never imports one.
• SchemaForm — the base component wiring all of the above over @rjsf/shadcn, with registry injection via prop or WidgetRegistryContext.

This package is host-agnostic: it contains no vendor vocabulary beyond the unprefixed form keywords it consumes itself (x-widget, x-placeholder). Vendor layers (dialects, pre-wired forms) belong in adapter packages that depend on this one.

Install

npm install @schemastud/seam

Peer dependencies: @rjsf/core, @rjsf/shadcn, @rjsf/utils, @rjsf/validator-ajv8 (all ^6), react (≥18).

Usage

import { SchemaForm, createWidgetRegistry } from '@schemastud/seam';

const registry = createWidgetRegistry();
registry.registerWidget((s) => s['x-widget'] === 'citation', CitationWidget);

<SchemaForm
    schema={schema}
    registry={registry}
    schemaFetcher={(ref) => api.get(ref).then((r) => r.data)}
    onSubmit={({ formData }) => save(formData)}
/>;

Default resolution chain

1. x-widget explicit override (textarea, radio, file, select)
2. enum: ≤4 entries → radio; larger → RJSF's select default
3. format: file → file widget; date/date-time/email/uri → native inputs
4. everything else → RJSF defaults (the registry emits nothing)

Quirks handled by SchemaForm

• Backends that serialize an empty associative payload as [] (PHP among them) get their formData coerced to {} against object schemas.
• Nullable $refs ({$ref, nullable: true}) are re-expressed as anyOf[$ref, null] (normalizeNullableRefs) — AJV rejects nullable without a type sibling. required is passed through untouched: the server's list is the form's list.
• Arrays without an items definition are hidden rather than rendered as RJSF error blocks.