The latest articles on DEV Community by Michael Hightower (@mhightower932). https://dev.to/mhightower932 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3879143%2F2a912f66-8b6f-4957-a5af-959bb1400bdc.png https://dev.to/mhightower932 en Michael Hightower Tue, 14 Apr 2026 18:32:41 +0000 https://dev.to/mhightower932/i-built-an-open-source-wms-because-every-warehouse-management-system-costs-2000month-5nc https://dev.to/mhightower932/i-built-an-open-source-wms-because-every-warehouse-management-system-costs-2000month-5nc <p>Every WMS on the market is either a six-figure enterprise implementation, a $500-3,000/month SaaS with workflows you can't change, or an ERP bolt-on that was never designed for a warehouse floor. There has never been a credible open-source alternative built for e-commerce fulfillment. Today that changes.</p> <p>I'm a warehouse manager at an e-commerce company. 8,000 orders/month, 5 scanning stations, and I function as the entire technology department. I needed a WMS that didn't force my team into someone else's workflow. Nothing existed that fit, so I built one.</p> <h2> What Sentry WMS does </h2> <p>Full warehouse lifecycle, all scan-driven:</p> <ul> <li> <strong>Receiving</strong> : scan PO, scan items, track quantity, complete</li> <li> <strong>Put-Away</strong> : scrollable list, scan any item in any order, scan destination bin</li> <li> <strong>Pick Walk</strong> : item counter, next preview, optimized path</li> <li> <strong>Pack Verification</strong> : scan SO, scan items to verify, confirmed rows</li> <li> <strong>Shipping</strong> : carrier picker, tracking entry, completion</li> <li> <strong>Cycle Count</strong> : blind/non-blind, pending records, admin per-bin approve/reject</li> <li><strong>Bin-to-Bin Transfer</strong></li> <li> <strong>Admin Panel</strong> : inventory, items, POs, SOs, users, warehouses, settings, import, audit log</li> </ul> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fjfxzykzy4iiprc4o5j39.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fjfxzykzy4iiprc4o5j39.png" alt=" " width="800" height="420"></a></p> <h2> Stack </h2> <ul> <li>Python/Flask API with parameterized SQL and service layer</li> <li>React 18 + Vite admin panel</li> <li>React Native (Expo) mobile app with broadcast intent scanner support</li> <li>PostgreSQL 16</li> <li>Docker Compose (one command to run the entire stack)</li> </ul> <h2> Security </h2> <p>I ran two independent security audits using Claude Opus and Sonnet in separate sessions. Opus identified vulnerabilities that were low-risk independently but dangerous once chained together. 18 vulnerabilities found and fixed total.</p> <p>Parameterized SQL on every query, warehouse authorization middleware on all endpoints, random admin password on first run, live DB validation on every authenticated request, login lockout, non-root container with gunicorn, security headers, and CORS restricted to configured origins.</p> <h2> Hardware testing </h2> <p>This wasn't built in a browser. I test on a Chainway C6000 industrial barcode scanner running Android 10. The mobile app uses broadcast intents (com.chainway.sdk.barcode.BARCODE_DECODING_DATA), not keyboard wedge, not camera scan. Real warehouse hardware.</p> <p>The standalone APK is attached to the GitHub release.</p> <h2> Get running in one command </h2> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code>git clone https://github.com/hightower-systems/sentry-wms.git <span class="nb">cd </span>sentry-wms docker compose up <span class="nt">-d</span> </code></pre> </div> <p>Admin panel at <code>http://localhost:3000</code>. Admin password is randomly generated on first run, check <code>docker compose logs</code> for credentials. Demo data included so you can explore immediately.</p> <p>For production (no demo data):<br> </p> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code><span class="nv">SKIP_SEED</span><span class="o">=</span><span class="nb">true </span>docker compose up <span class="nt">-d</span> </code></pre> </div> <h2> What's next </h2> <ul> <li> <strong>v1.1:</strong> Input validation schemas, Redis rate limiting, error boundaries, MkDocs documentation site</li> <li> <strong>v2.0:</strong> ERP connector framework; NetSuite, Shopify, BigCommerce</li> <li> <strong>Sentry Cloud:</strong> Hosted SaaS for teams that don't want to self-host</li> </ul> <p>Sentry is the warehouse execution layer. Your ERP stays the system of record.</p> <h2> Numbers </h2> <ul> <li>288 automated tests passing in ~28 seconds</li> <li>4,000+ lines of Python</li> <li>Two full security audits</li> <li>MIT licensed</li> <li>Free forever</li> </ul> <p><strong>GitHub:</strong> <a href="https://github.com/hightower-systems/sentry-wms" rel="noopener noreferrer">https://github.com/hightower-systems/sentry-wms</a></p> <p><strong>Demo videos:</strong> <a href="https://github.com/hightower-systems/sentry-wms/releases/tag/v1.0.0" rel="noopener noreferrer">v1.0.0 Release Page</a></p> <p>If you run a warehouse, manage inventory, or just want to poke at the code, I'd love feedback. Star it, fork it, break it.</p> opensource python docker react