Joshua Jordan

Dependent Media Live Rates for USPS calculates real-time USPS shipping rates at checkout using your own USPS Developer Portal credentials, by talking directly to the USPS REST API (the current API — not the retired Web Tools API).
This plugin is not affiliated with or endorsed by the United States Postal Service. “USPS” is a trademark of the United States Postal Service and is used in this plugin’s name solely to describe the service the plugin integrates with.
<h4>Domestic US</h4>
<ul>
<li>USPS Ground Advantage</li>
<li>USPS Priority Mail</li>
<li>USPS Priority Mail Express</li>
</ul>
<h4>International</h4>
<ul>
<li>USPS First-Class Package International</li>
<li>USPS Priority Mail International</li>
<li>USPS Priority Mail Express International</li>
</ul>
<h4>Other features</h4>
<ul>
<li>Per-product weight and dimensions, with configurable defaults for products that have none set</li>
<li>Separate domestic and international service toggles — enable only what you want to offer</li>
<li>Automatic routing: the plugin detects destination country and hits the right USPS endpoint</li>
<li>Multi-box packing by default — each cart line item is rated as its own package and costs are summed. Heavy lines are automatically split across multiple boxes to stay within USPS weight caps. A “combined” mode is also available for stores that genuinely ship everything in one box.</li>
<li>Only services that price every box are offered — partial coverage would produce a misleading total</li>
<li>Optional fallback flat rate if the USPS API is unreachable</li>
<li>Debug logging via WooCommerce → Status → Logs</li>
</ul>
<h4>You bring your own USPS API credentials</h4>
This plugin does not proxy rate requests through any third party. You register your store as a USPS Developer Portal application once, paste the Consumer Key and Consumer Secret into the plugin settings, and rates go directly from USPS to your site. There is no monthly fee and no per-request cost.
Register at: <a href="https://developers.usps.com/" rel="nofollow ugc">https://developers.usps.com/</a>
<h4>Privacy</h4>
When a customer reaches checkout, the plugin sends the destination postal code (and country, for international) along with the package dimensions and weight to the USPS REST API at <code>apis.usps.com</code>. No customer name, email, or other personally identifying information is transmitted. OAuth2 access tokens are cached locally in a WordPress transient.
<h4>Source code</h4>
Development happens on GitHub: <a href="https://github.com/Dependent-Media/dm-usps-shipping" rel="nofollow ugc">https://github.com/Dependent-Media/dm-usps-shipping</a>. Issues and pull requests welcome.
<h3>External services</h3>
This plugin connects to the USPS (United States Postal Service) REST API to obtain live shipping rates at WooCommerce checkout. This is the entire purpose of the plugin: without this connection, no rates can be calculated.
What is the service? The USPS REST API at <code>https://apis.usps.com</code>, operated by the United States Postal Service. The plugin uses two endpoints:
<ul>
<li><code>POST /oauth2/v3/token</code> — to obtain an OAuth2 access token using the merchant’s USPS Developer Portal Consumer Key and Consumer Secret.</li>
<li><code>POST /prices/v3/total-rates/search</code> and <code>POST /international-prices/v3/total-rates/search</code> — to obtain shipping rates for a given package.</li>
</ul>
What data is sent, and when?
<ul>
<li>When a customer reaches the WooCommerce shipping calculation step (typically the Cart or Checkout page), the plugin sends, for each package being rated: the origin ZIP code (configured by the merchant), the destination postal code, the destination country, and the package weight, length, width, and height.</li>
<li>When the plugin needs to authenticate to the USPS API (the first time, and again when the cached token has expired), it sends the merchant’s USPS Consumer Key and Consumer Secret to the OAuth2 token endpoint.</li>
<li>No customer name, email address, IP address, or other personally identifying information is transmitted to USPS by this plugin.</li>
</ul>
Who provides the service? The United States Postal Service.
<ul>
<li>USPS Developer Portal Terms and Conditions: <a href="https://developers.usps.com/terms-and-conditions" rel="nofollow ugc">https://developers.usps.com/terms-and-conditions</a></li>
<li>USPS Privacy Policy: <a href="https://www.usps.com/privacypolicy/" rel="nofollow ugc">https://www.usps.com/privacypolicy/</a></li>
</ul>
Is the use of this service required? Yes. Calculating live USPS rates is the plugin’s only function, and it cannot be performed without contacting the USPS REST API. Merchants who do not wish to use this service should not install or activate this plugin.

Dependent Media Live Rates for USPS

Live USPS rates for WooCommerce via the current USPS REST API. Domestic and international, with multi-box packing. No middleman, no monthly fee.

sulemanshahjahan

Precision Live Rates brings real, account-accurate UPS, USPS, FedEx, DHL, and Stamps.com prices into WooCommerce’s cart and checkout. No flat-rate guesswork, no aggregator markups bolted on top of the carrier rate, no rate drift between cart and checkout. The numbers your customers see are the same numbers you’d see on the carrier dashboard for the same parcel.
Under the hood, the plugin packs each cart into the smallest viable parcel using a true 3D bin-packing algorithm (volume-then-SKU-then-product-id deterministic sort, ships-alone overrides honored, custom-packed dimensions for soft goods supported), POSTs the parcel to ShipEngine over HTTPS, dedupes the rate response by carrier+service, and caches the result on your server so identical carts don’t trigger redundant API calls. The same <code>RateService::quote()</code> entry point feeds Classic Checkout, Blocks Checkout, and the WP-CLI <code>wp precision-rates test-rate</code> command — so cart, checkout, and your terminal all return byte-identical rates within the cache TTL.
The diagnostic surface is built for real-world support load. The Rate Test admin screen captures every quote attempt’s full request and response from ShipEngine into a 1-hour transient and surfaces it inline (collapsible, color-coded by HTTP status) so when a customer reports “no shipping options,” you can see exactly which carrier returned what. The Services screen auto-discovers every <code>carrier:service_code</code> flowing through the rate filter and lets you uncheck the ones you don’t want shown. The Plugin Status panel on the Overview tab reports the running version, saved API key state, active carriers, cache TTL, and current markup at a glance — so verifying “is the new code actually live with my settings” is a glance, not an SSH dive.
Privacy and compliance are first-class. The plugin transmits only postal codes, country codes, and parcel dimensions to ShipEngine — never customer name, email, IP, billing address, or order ID. Suggested privacy-policy boilerplate auto-registers with WP’s Settings → Privacy editor on activation. Personal-data exporter and eraser hooks are wired so the WP Tools → Export/Erase Personal Data flows recognize the plugin as compliant. EU/UK merchants can flip on a Settings → Privacy toggle to render a “Shipping rates calculated using ShipEngine — Privacy policy” line under the cart and checkout shipping options.
<h4>Highlights</h4>
<ul>
<li>Real carrier rates via ShipEngine’s <code>/v1/rates</code> endpoint — UPS, USPS, FedEx, DHL Express, Stamps.com all behind a single API key. Or connect UPS / USPS directly with your own developer credentials.</li>
<li>True 3D bin-packing via the <code>dvdoug/boxpacker</code> library. Define your box catalog under WooCommerce → Box catalog and items pack into the smallest viable box, ships-alone items respected.</li>
<li>Cart = checkout, byte-identical, within the cache TTL. Single quote pipeline shared by Classic Checkout, Blocks Checkout, and WP-CLI.</li>
<li>Encrypted credentials at rest via <code>sodium_crypto_secretbox</code>, derived per-install from <code>wp_salt('auth') . AUTH_KEY</code>. The plugin refuses to encrypt anything when AUTH_KEY is missing or matches the WP install placeholder.</li>
<li>Per-carrier markup to bridge negotiated rates to retail-equivalent prices. ShipEngine returns each carrier’s negotiated rate (UPS often runs 30-50% below ups.com retail); set “UPS markup %” to 65-75 to display retail-equivalent prices without overcharging USPS shipments.</li>
<li>Rate Test diagnostic screen captures the raw request/response of every quote — when checkout shows a price you didn’t expect, this is the source of truth.</li>
<li>Services whitelist auto-discovered from carrier responses; uncheck what you don’t want shown to customers.</li>
<li>GDPR-compliant out of the box. Privacy policy boilerplate, WP exporter/eraser hooks, opt-in cart disclosure line.</li>
<li>i18n-ready — English (source), Spanish (es_ES), French (fr_FR) bundled. Other locales contribute via translate.wordpress.org once the plugin lists, or via pull request to the repo.</li>
<li>HPOS-required. No legacy order-table compatibility shims. Modern WC only.</li>
</ul>
<h4>Out of scope</h4>
The plugin is intentionally focused on rate calculation. It does not purchase shipping labels, generate manifests, schedule pickups, sync tracking webhooks back to order status, or integrate with multi-vendor marketplaces (Dokan, WCFM). For label printing and fulfillment, use ShipStation / ShipEngine’s own dashboard or a separate WC label plugin.
<h3>Privacy & data handling</h3>
This plugin transmits cart/shipment data to a third-party rate aggregator (ShipEngine, https://www.shipengine.com/) over HTTPS to calculate live carrier rates. Specifically, on each rate quote the following is sent:
<ul>
<li>Origin postal code + country (and optionally street/city/state, as configured in plugin settings)</li>
<li>Destination postal code + country (and street/city/state if the customer supplied them)</li>
<li>Parcel weight and dimensions, computed from the cart contents</li>
</ul>
The customer’s name, email, phone, IP address, billing address, and order ID are NOT transmitted. Successful rate responses are cached on your server for a short, merchant-configurable duration (60–3600 seconds, default 60). The cache is keyed on parcel dimensions and origin/destination ZIP only — it is not keyed on or attributable to any individual customer.
EU/UK merchants should turn on Settings → Privacy → “Display privacy disclosure on cart/checkout” so a small “Shipping rates calculated using ShipEngine — Privacy policy” line renders under the cart and checkout shipping options. Suggested privacy-policy boilerplate is auto-registered with WP’s Settings → Privacy → Policy guide editor on plugin activation.
The plugin also registers no-op personal-data exporter and eraser hooks with WordPress so the Tools → Export Personal Data and Tools → Erase Personal Data flows recognise it as compliant — there is nothing per-customer to export or erase, but the hooks are present so the privacy admin’s audit trail correctly accounts for the plugin.
Full data-flow documentation, including the GDPR / CCPA / Quebec Law 25 compliance summary, is in PRIVACY.md at the repo root. ShipEngine’s own data-handling practices are at https://auctane.com/privacy-policy/ (Auctane is ShipEngine’s parent company).
<h3>External services</h3>
Precision Live Rates calls third-party shipping APIs to obtain live carrier rates. No external service is called until the merchant has explicitly enabled and configured at least one carrier source. The data sent is limited to what is needed to compute a shipping price — see the Privacy & data handling section above for the exact payload.
ShipEngine (https://www.shipengine.com/) 
* What it is: a rate-aggregation API that fronts UPS, USPS, FedEx, DHL Express, and Stamps.com. 
* What is sent: origin postal code, destination postal code + country, parcel weight + dimensions, and the configured ShipEngine carrier IDs. No customer name, email, IP, or order ID. 
* When it is called: on the cart and checkout pages when WooCommerce asks for shipping rates and the cached rate has expired (default 60 seconds). 
* Why: to compute live shipping prices that match what the carrier itself would charge. 
* Terms of service: https://www.shipengine.com/terms-of-service/ 
* Privacy policy: https://auctane.com/privacy-policy/ (Auctane is ShipEngine’s parent company)
UPS Developer APIs (optional, https://developer.ups.com/) 
* What it is: UPS’s official rate API. 
* What is sent: same shape as ShipEngine, plus the merchant’s UPS account number. 
* When it is called: only when the merchant has explicitly enabled UPS direct under Settings → UPS direct and saved valid UPS developer credentials. 
* Why: lets merchants who have a direct UPS contract bypass ShipEngine and quote against their negotiated rate sheet. 
* Terms of service: https://www.ups.com/upsdeveloperkit/agreement 
* Privacy policy: https://www.ups.com/us/en/help-center/legal-terms-conditions/privacy-notice.page
USPS Developer APIs (optional, https://developer.usps.com/) 
* What it is: the United States Postal Service’s official rate API. 
* What is sent: origin and destination postal codes, parcel weight + dimensions. 
* When it is called: only when the merchant has explicitly enabled USPS direct under Settings → USPS direct and saved valid USPS developer credentials. 
* Why: lets merchants who have a direct USPS account quote against USPS retail rates without ShipEngine in the path. 
* Terms of service: https://www.usps.com/terms-conditions/general.htm 
* Privacy policy: https://about.usps.com/who/legal/privacy-policy/welcome.htm

Precision Live Rates for WooCommerce

Live UPS, USPS, FedEx, DHL, Stamps.com rates via ShipEngine. Deterministic 3D bin-packing. Cart=checkout, byte-identical.

Dependent Media Live Rates for USPS vs Precision Live Rates for WooCommerce