@rjsf/validator-cfworker

@rjsf/validator-cfworker is an additional validator option for CSP-constrained RJSF users. It uses @cfworker/json-schema to interpret schemas without eval or new Function, and defaults to JSON Schema draft 2020-12.

It is not an AJV replacement. Choose it when an eval-free runtime is more important than AJV-specific keywords, extensions, localization, or code generation.

import Form from '@rjsf/core';
import validator from '@rjsf/validator-cfworker';

export default function Example() {
  return <Form schema={{ type: 'string' }} validator={validator} />;
}

Behavior

• Implements RJSF's ValidatorType<T, S, F> interface.
• Normalizes undefined before validation: undefined object members are omitted so required errors surface, while undefined array entries become null.
• Caches schema-bound engine instances by schema $id (or the RJSF schema hash) and refreshes them when the schema or root schema changes.
• Supports customValidate, transformErrors, custom formats, duplicate anyOf/oneOf filtering, and the RJSF color and data-url formats.
• Supports draft 4, draft 7, draft 2019-09, and draft 2020-12 through the draft customization option; the default is draft 2020-12.

import { customizeValidator } from '@rjsf/validator-cfworker';

const validator = customizeValidator({
  draft: '2020-12',
  shortCircuit: false,
  customFormats: {
    'phone-us': /\(?\d{3}\)?[\s-]?\d{3}[\s-]?\d{4}$/,
  },
});

Unsupported-keyword matrix

Unknown keywords are annotations to the underlying engine, so unsupported extensions are not validation constraints.

| Keyword or extension | Status | Notes | | --- | --- | --- | | $dynamicRef / $dynamicAnchor | Unsupported | Tracked upstream in cfworker/json-schema#150. | | AJV $data references | Unsupported | AJV-specific extension; use literal schema values. | | OpenAPI discriminator | Unsupported | Use standard oneOf constraints without discriminator semantics. | | errorMessage from ajv-errors | Unsupported | Use RJSF's transformErrors hook instead. |

Precompiled-validator mode is intentionally outside this initial package. Runtime error messages also differ from AJV, and there is no ajv-i18n equivalent.

Upstream state and provenance

This package is ported from glama-ai/rjsf-validator-cfworker, whose structure was intentionally kept compatible with RJSF. The original MIT copyright and license are preserved in LICENSE; the RJSF integration and subsequent changes are distributed under the monorepo's Apache-2.0 license.

The underlying @cfworker/json-schema package's latest release is from January 2025. Its tracker includes open correctness reports for duplicate schema URIs (#335) and additionalProperties behavior (#336), as well as the $dynamicRef gap above. This wrapper's per-schema cache avoids repeat registration on RJSF's isValid path, but it does not change the upstream engine's other semantics. The package is therefore presented as an additional option for CSP-constrained users.