nextauthjs/next-auth · error · Error

Missing required field: ${field.name}

Error message

Missing required field: ${field.name}

What it means

registrationFlow validates that every required WebAuthn form field has a value before starting passkey registration with the browser. If any field marked required is empty or falsy, it throws immediately to stop an incomplete registration attempt from reaching the WebAuthn ceremony.

Source

Thrown at packages/core/src/lib/utils/webauthn-client.js:145

    // Start authentication
    const authResp = await WebAuthnBrowser.startAuthentication(
      options,
      autofill
    )

    // Submit authentication response to server
    return await submitForm("authenticate", authResp)
  }

  /**
   * @param {WebAuthnOptionsReturn<WebAuthnRegister>['options']} options
   */
  async function registrationFlow(options) {
    // Check if all required formFields are set
    const formFields = getFormFields()
    formFields.forEach((field) => {
      if (field.required && !field.value) {
        throw new Error(`Missing required field: ${field.name}`)
      }
    })

    // Start registration
    const regResp = await WebAuthnBrowser.startRegistration(options)

    // Submit registration response to server
    return await submitForm("register", regResp)
  }

  /**
   * Attempts to authenticate the user when the page loads
   * using the browser's autofill popup.
   *
   * @returns {Promise<void>}
   */
  async function autofillAuthentication() {
    // if the browser can't handle autofill, don't try

View on GitHub (pinned to a1a16a5a77)

Solutions

1. Validate the form in the UI and prevent submission until all required fields have values
2. Check getFormFields() output and ensure every required field is populated before calling registrationFlow
3. Mark fields as required:false if they genuinely are optional in your setup
4. Improve UX by surfacing which specific field failed (the field name is in the message)

Example fix

// before
await registrationFlow(options) // throws if required fields empty
// after
const fields = getFormFields()
const missing = fields.filter(f => f.required && !f.value)
if (missing.length === 0) {
  await registrationFlow(options)
} else {
  setFieldErrors(missing.map(f => f.name))
}

const missing = getFormFields().filter(f => f.required && !f.value)
if (missing.length > 0) {
  throw new Error(`Fill required fields: ${missing.map(f => f.name).join(", ")}`)
}
await registrationFlow(options)

null

null

When it happens

Trigger: Calling registrationFlow (typically from setupForm) when a required field such as username, email, or name has an empty value in the formFields returned by getFormFields().

Common situations: Users submitting the passkey setup form without filling required inputs; forms where autocomplete or prefills silently clear a field; custom forms that forget to bind a required input to the field value; language-specific field names that differ from the default.

Understand the failure class

Background: "Missing required field" and "field is required" errors: why libraries reject payloads that omit mandatory fields — this error's family across 20 libraries.

Related errors

• Authenticator not found.
• Authenticator not found.
• Authenticator not found.
• Authenticator not created
• Verification Token not found

AI-assisted analysis of nextauthjs/next-auth@a1a16a5a77 (2026-08-28). Data as JSON: /api/errors/1380224da1b6a3c6. Report an issue: GitHub.