RocketChat/Rocket.Chat · error · Error

Invalid custom fields

Error message

Invalid custom fields

What it means

When custom fields are enabled, the message's customFields object is validated against the ajv schema compiled from Message_CustomFields; a mismatch throws a plain Error 'Invalid custom fields'. Because the compiler forces additionalProperties: false, any key not declared in the setting's properties rejects the whole message, as do wrong types and missing required fields.

Source

Thrown at apps/meteor/server/lib/messaging/validateCustomMessageFields.ts:40

	customFields,
	messageCustomFieldsEnabled,
	messageCustomFields,
}: {
	customFields: Record<string, any>;
	messageCustomFieldsEnabled: boolean;
	messageCustomFields: string;
}) => {
	// get the json schema for the custom fields of the message and validate it using ajv
	// if the validation fails, throw an error
	// if there are no custom fields, the message object remains unchanged

	if (messageCustomFieldsEnabled !== true) {
		throw new Error('Custom fields not enabled');
	}

	const validate = customFieldsValidate(messageCustomFields);
	if (!validate(customFields)) {
		throw new Error('Invalid custom fields');
	}
};

View on GitHub (pinned to b2c16d5842)

Solutions

1. Align the payload with the configured schema: only declared keys with correct types
2. Update Message_CustomFields to declare new keys before sending them
3. Pre-validate customFields with the same schema client-side before calling the send API

Example fix

// before - schema declares ticketId as string only
await sendMessage(user, { ...message, customFields: { ticketId: 42, extra: 'x' } }, room);

// after - match declared keys and types
customFields: { ticketId: '42' }

// Pre-validate with the same schema the server compiles
const validate = ajv.compile({ ...workspaceCustomFieldsSchema, type: 'object', additionalProperties: false });
if (!validate(customFields)) {
  return reportFieldErrors(validate.errors);
}
await sendMessage(user, { ...message, customFields }, room);

const matchesCustomFieldsSchema = (fields: Record<string, unknown>): boolean => {
  const declared = Object.keys(workspaceSchema.properties || {});
  return Object.keys(fields).every((k) => declared.includes(k));
};

try {
  await sendMessage(user, { ...message, customFields }, room);
} catch (e) {
  if (e instanceof Error && e.message === 'Invalid custom fields') {
    showFieldValidationErrors(customFields); // tell the user which keys/types are wrong
  }
}

When it happens

Trigger: sendMessage/updateMessage with customFields containing keys not declared in the Message_CustomFields schema (rejected by additionalProperties: false), values of the wrong type, or missing required properties.

Common situations: Client and workspace schema drifting apart after admins edit the setting; integrations sending extra metadata keys; renamed fields after a schema update.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• Invalid custom fields config
• Custom fields not enabled
• invalid-token
• Invalid response from Rocket.Chat Cloud
• failed type validation

AI-assisted analysis of RocketChat/Rocket.Chat@b2c16d5842 (2026-08-18). Data as JSON: /api/errors/01a55ec7c8ada3fb. Report an issue: GitHub.