Technical guides for USPS v3 REST migration, address validation, rate limits, pricing comparisons, and shipping workflow architecture.https://revaddress.com/en-ushttps://revaddress.com/blog/easypost-march-2026-migration/https://revaddress.com/blog/easypost-march-2026-migration/EasyPost's March 17, 2026 enforcement is live. See what changed, the Free Access vs BYOCA cost impact, and flat-rate alternatives after enforcement.Tue, 17 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shipping-api-comparison-2026/https://revaddress.com/blog/shipping-api-comparison-2026/Compare EasyPost, Shippo, ShipEngine, and RevAddress for USPS integration. Pricing, code samples, migration paths, and where flat monthly beats per-label fees.Tue, 17 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-migration-guide/https://revaddress.com/blog/usps-migration-guide/Step-by-step USPS Web Tools migration guide covering endpoint mapping, OAuth setup, rate-limit handling, and working v3 REST code samples.Tue, 17 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-web-tools-shutdown-2026/https://revaddress.com/blog/usps-web-tools-shutdown-2026/USPS retired the Web Tools XML API on January 25, 2026. See what broke, which platforms were affected, and the fastest migration path to the v3 REST API.Tue, 17 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/smarty-vs-revaddress/https://revaddress.com/blog/smarty-vs-revaddress/Detailed comparison of Smarty and RevAddress for USPS address validation. Pricing, batch support, caching, and API design compared side-by-side.Thu, 12 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/easypost-march-17-deadline-migration-options/https://revaddress.com/blog/easypost-march-17-deadline-migration-options/EasyPost's March 17, 2026 plan enforcement is live. Compare migration options with exact cost savings at 1K-50K labels/mo, side-by-side code examples, and a 5-step migration checklist.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/easypost-vs-revaddress/https://revaddress.com/blog/easypost-vs-revaddress/Factual pricing comparison between EasyPost and RevAddress for USPS shipping APIs. Per-label vs flat pricing math, feature comparison, and when each wins.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/magento-usps-ac15210-fix/https://revaddress.com/blog/magento-usps-ac15210-fix/The built-in Magento USPS module broke when Web Tools retired. Here's the AC-15210 fix: a drop-in v3 REST API carrier that restores live rates and protected managed tracking routes.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shipengine-vs-revaddress/https://revaddress.com/blog/shipengine-vs-revaddress/ShipEngine vs RevAddress for USPS shipping integration. Pricing tiers, API design, code samples, and the real question: do you need 200 carriers or one really good one?Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shippo-vs-revaddress/https://revaddress.com/blog/shippo-vs-revaddress/Head-to-head comparison of Shippo and RevAddress for USPS shipping. Pricing at every volume tier, architecture differences, code samples, and when to pick each one.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-access-control-april-2026/https://revaddress.com/blog/usps-api-access-control-april-2026/USPS is launching its API Access Control initiative in April 2026, restricting tracking data access for service providers. What changes, who's affected, and how to prepare.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-package-replacement/https://revaddress.com/blog/usps-api-package-replacement/The usps-api PyPI package, usps-webtools, and usps-webtools-promise npm packages are dead. They target the retired USPS Web Tools XML API shut down January 2026. Here's the one-command migration to the usps-v3 SDK.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-pricing-2026-what-it-really-costs/https://revaddress.com/blog/usps-api-pricing-2026-what-it-really-costs/The USPS API is free to use directly — but rate limits make it impractical at scale. Here's the real cost breakdown for direct access, EasyPost, Shippo, and RevAddress.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-rate-limits-2026-what-changed/https://revaddress.com/blog/usps-api-rate-limits-2026-what-changed/USPS v3 API dropped from ~6,000 requests/min to 60/hour. Why it happened, what it means for production shipping, and five architecture patterns with working code to handle it.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-april-2026-access-control-changes/https://revaddress.com/blog/usps-april-2026-access-control-changes/USPS is restructuring API access control in April 2026 — the second wave of breaking changes after the January Web Tools retirement. Timeline, what's changing, action items, and how to build an integration that survives both waves.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-batch-address-validation-api/https://revaddress.com/blog/usps-batch-address-validation-api/Validate up to 50 US addresses in a single API call with RevAddress. Parallel processing, 24-hour caching, and $0.002/validation — 5x cheaper than EasyPost or Shippo.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-crid-mid-enrollment/https://revaddress.com/blog/usps-crid-mid-enrollment/Step-by-step guide to USPS CRID registration, Mailer ID (MID) enrollment, EPA setup, and COP claims linking for the v3 REST API. The guide that USPS PDFs should have been.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-oauth-troubleshooting/https://revaddress.com/blog/usps-oauth-troubleshooting/Getting 401s, 403s, or token refresh failures from the USPS v3 API? This guide covers every OAuth error, the two-token lifecycle, and Payment Authorization gotchas.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-address-validation-quickstart/https://revaddress.com/blog/usps-v3-address-validation-quickstart/Validate a US address with the USPS v3 REST API in one curl command. Working code for Python, Node.js, and curl — no XML, no USERID, no middleman.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-migration-guide-nodejs-python/https://revaddress.com/blog/usps-v3-migration-guide-nodejs-python/Step-by-step migration guide from USPS Web Tools XML API to v3 REST using the usps-v3 Python and Node.js SDKs. Side-by-side code comparison, OAuth setup, endpoint mapping, and testing checklist.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-node-quickstart/https://revaddress.com/blog/usps-v3-node-quickstart/Install the usps-v3 Node.js SDK and start validating addresses, querying tracking routes, and running USPS label workflows in minutes. Full TypeScript support, zero dependencies.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-php-quickstart/https://revaddress.com/blog/usps-v3-php-quickstart/Install the revaddress/usps-v3-php Composer package and start validating addresses, querying tracking routes, and running USPS label workflows in PHP. Works with Magento, WooCommerce, and Laravel.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-python-quickstart/https://revaddress.com/blog/usps-v3-python-quickstart/Install the usps-v3 Python SDK and start validating addresses, tracking packages, and comparing shipping rates in minutes. Full code examples with type hints.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-sdk-comparison/https://revaddress.com/blog/usps-v3-sdk-comparison/Install the usps-v3 SDK for Python, Node.js, or PHP. Automatic OAuth, address validation, tracking routes, label workflows, and pricing. MIT licensed, zero config, and production-tested.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-web-tools-endpoint-mapping/https://revaddress.com/blog/usps-web-tools-endpoint-mapping/Definitive USPS Web Tools XML to v3 REST mapping across addresses, tracking, labels, pricing, and locations.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-web-tools-migration-checklist/https://revaddress.com/blog/usps-web-tools-migration-checklist/Step-by-step checklist for migrating from USPS Web Tools XML to the v3 REST API. Covers OAuth, endpoint mapping, error handling, and testing — nothing skipped.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/woocommerce-usps-migration/https://revaddress.com/blog/woocommerce-usps-migration/Step-by-step guide to replace your broken WooCommerce USPS shipping plugin with RevAddress's v3 REST API module. Live rates, address validation, OAuth — no XML.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-rate-limits/https://revaddress.com/blog/usps-rate-limits/Practical strategies for handling USPS v3 API rate limits. Caching, batching, queue architecture, and BYOK for production workloads.Mon, 09 Mar 2026 00:00:00 GMT