SIP-11: Transaction insight severity levels Source

Author Hassan Malik
Status Draft
Created 2023-07-16


This SIP proposes a way for snaps to provide extra friction for executing potentially dangerous transactions within MetaMask with the addition of a severity field to the already existing transaction insights API outlined in SIP-3.


One of the biggest issues with wallet users is a loss of funds through executing some sketchy or seemingly innocuous transaction. With the benefit of the transaction insights API, a snap can already run analysis on an unsigned transaction payload. By adding severity to the existing API, we allow for the snap to provide extra friction to the user if it determines that a transaction is malicious. Users often click through things without reading, by allowing for a warning we can add friction at points that we really think a user should have a second glance.

This warning could be injected at any point where there are insights provided.

MetaMask Integration

The severity key is added to the return object to indicate the severity level of the content being returned to the extension. This will help trigger certain UI in the extension. Currently, a warning modal will be triggered for content with a severity level of critical. The modal will require a checkbox to be checked before the user can continue with the transaction.

In future SIPs, the SeverityLevel enum can be expanded to include other levels that can be also be used to influence the UI in the extension.

Transaction insight snaps were previously triggered on view of their respective tabs, but with the addition of the severity key, execution would become unprompted in order to determine if a modal needs to be displayed as you reach the confirmation screen.

Snap Implementation

The following is an example implementation of the API:

import { OnTransactionHandler } from "@metamask/snap-types";

enum SeverityLevel {
  Critical = 'critical',

export const onTransaction: OnTransactionHandler = async ({
}) => {
  const content = /* Get UI component with insights */;
  const isContentCritical = /* Boolean checking if content is critical */
  return isContentCritical ? { content, severity: SeverityLevel.Critical } : { content };

The interface for the return value of an onTransaction export is:

interface OnTransactionResponse {
  content: Component | null;
  severity?: SeverityLevel;

Note: severity is an optional field and the omission of such means that there is no escalation of the content being returned.


Please see SIP-3 for more information on the original transaction insights API.

Please see the SIP-7 package for more information on the Component type returned in the OnTransactionResponse.

Copyright and related rights waived via CC0.


Please cite this document as:

Hassan Malik, "SIP-11: Transaction insight severity levels [DRAFT]," Snaps Improvement Proposals, no. 11, July 2023. [Online serial]. Available: