# TCVS Extension

> Enables secure CORS-compliant communication between Corelation Keystone credit union systems and U.S. Treasury Check Verification

Canonical page: [https://chrome-stats.com/d/tcvs-extension](https://chrome-stats.com/d/tcvs-extension)

## Overview

- **ID:** `tcvs-extension`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** TTCU Technologies
- **Category:** web-development,privacy-security
- **Daily users:** 7
- **Version:** 2.4.0
- **Last updated:** 2025-07-10
- **First published:** 2025-06-29
- **Size:** 1.37 MB
- **Data as of:** 2026-09-09
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/tcvs-extension/)
- **Website:** [https://www.ttcu.tech](https://www.ttcu.tech/)

## Description

Enables secure CORS-compliant communication between Corelation Keystone credit union systems and U.S. Treasury Check Verification Service. Seamlessly verify checks against the Treasury database without CORS restrictions. Essential for credit unions.

Overview

The TCVS Extension provides a secure bridge between credit union web applications and the U.S. Treasury's Check Verification Service (TCVS) API. By intelligently managing CORS headers, this extension enables Corelation Keystone systems to verify check information in real-time against the official Treasury database.

Requirements
<ul><li>Firefox browser (Desktop or Android)</li><li>Valid TCVS API subscription from U.S. Treasury</li><li>Corelation Keystone or compatible credit union system</li></ul>

## Rankings

- #39,278 — Overall

## Permissions and access

### Permissions

- `webRequest`
- `webRequestBlocking`
- `storage`
- `tabs`
- `https://tcvs.fiscal.treasury.gov/*`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** High risk impact
- **Risk likelihood:** Moderate risk likelihood

### Analysis details

- Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

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Source: [Chrome-Stats](https://chrome-stats.com/d/tcvs-extension)