Oversize Permits.
One API. Every State.
OSOW API simplifies oversize/overweight permitting with structured data, automated matching, and blazing-fast endpoints for all 50 U.S. states.
No credit card required. Cancel anytime.
Why I Built OSOW API
I spent years in trucking and freight dispatch. Every day, I saw how hard it was for honest carriers to get clear answers on what routes they could run. One DOT would say one thing, another would say something else, and you'd waste hours digging through PDFs or calling permit offices.
OSOW API is my way of fixing that. I believe permit data should be structured, accessible, and automated — because compliance shouldn't be guesswork.
With respect,
Colby Barr
Founder, LoadFlow Logistics
Before vs After OSOW API
Most teams waste hours cross-checking permit rules and formatting paperwork manually. OSOW eliminates guesswork with structured, API-ready automation.
| Task | Before OSOW | With OSOW |
|---|---|---|
| Permit Research | Google PDFs, call DOTs, email agents | Single API call returns full rules |
| Permit Matching | Manual form review + guesswork | SmartMatcher gives instant result |
| PDF & Invoice Handling | Hand-filled spreadsheets or emails | Auto-generated + downloadable |
| Escorts & Legal Limits | Guess based on past loads | Rule-enforced validation engine |
| Audit Trails | Scattered email chains or paper | Auto-logged + searchable logs |
What Can OSOW API Do?
From permit research to full automation, OSOW gives your logistics or compliance team superpowers — without needing to learn 50 state websites.
50-State Permit Rules
Instantly query oversize/overweight rules for any U.S. state — dimension limits, escort triggers, holiday restrictions, and more.
Smart Permit Matcher
Drop in load specs and receive the best-fit permit type — including estimated fees, confidence score, and permit notes.
Webhook Alerts
Automatically receive updates when rules change, states update fees, or your requests exceed compliance thresholds.
Permit Bundling
Group loads into projects, track state-by-state submission status, and export full bundles as ZIP or CSV for team collaboration.
Auto PDFs & Invoices
Generate branded documents in seconds — PDFs for client delivery, invoices for billing, and audit logs for compliance checks.
Access Control & Billing
Tiered API keys, usage caps, team-level permissions, and real-time billing powered by Stripe — secure and scalable.
Try the API Instantly
The fastest way to understand OSOW is to make a real request. Here's what it looks like to fetch Texas oversize rules — no signup required.
curl -X GET https://api.osow.io/v1/state/TX \ -H "Authorization: Bearer YOUR_API_KEY"
fetch("https://api.osow.io/v1/state/TX", {
headers: {
Authorization: "Bearer YOUR_API_KEY"
}
})
.then(res => res.json())
.then(data => console.log(data));Trusted. Verified. Transparent.
OSOW API is built for the real world. From PCI-compliant billing to DOT-sourced data, our infrastructure supports carriers, brokers, and developers with audit-grade reliability.
Stripe Secure Billing
All payments are processed via Stripe with full PCI-DSS compliance and encryption. We never store card data.
99.99% Uptime Commitment
Our API is monitored 24/7 with uptime guarantees, latency tracking, and automatic alerting in case of errors.
Verified DOT Sources
Every field in our dataset is manually checked against state DOT websites, official applications, and rulebooks.
Logged & Auditable
Every API request is timestamped, stored securely, and can be replayed for compliance review or debugging.
Audit logs and historical permit data snapshots available for enterprise clients upon request.
Milestones & Roadmap
OSOW API has evolved from a single-state prototype to a 50-state commercial-grade platform. Here’s where we’ve been — and where we’re going.
Feb 2024
First internal MVP launched — basic Texas route data manually structured into JSON format.
June 2024
Dataset expanded to cover all 50 U.S. states with dimensional rules, escort triggers, and weekend restrictions.
March 2025
Stripe billing integration, API key system, usage tracking, and launch of tiered access levels via admin dashboard.
June 2025
Public launch: ZIP bundle export, CSV tools, webhook alerts, and full permit-matching logic released.
Aug 2025 (Upcoming)
Permit Filing Automation: AI-assisted form population + submission system for Texas, Florida, and California (beta).
Trusted by Innovators in Logistics
From solo dispatchers to national fleets, OSOW is built to streamline compliance and reduce permit guesswork for everyone.
Don’t see your logo? Let’s talk.
How OSOW API Works
See how a single API call replaces hours of manual research. Whether you're validating a load or planning a route, OSOW does the heavy lifting.
Want a deeper walkthrough? Try the live planner or book a demo.
Built for Developers
OSOW is a real API — not just a UI wrapper. Everything is designed to integrate cleanly with your workflows, backends, or automations.
Token-Based Auth
Secure API keys with per-plan rate limits. Headers are simple:Authorization: Bearer ...
Rate Limits by Plan
Every API plan has enforced per-minute and per-day quotas. Headers return `X-RateLimit-Remaining` and `Retry-After`.
Webhook Support
Get notified instantly when rule updates happen or when your load specs violate a threshold. POSTs to your webhook URL.
Versioned Endpoints
Everything lives under /api/v1/...with future upgrades scoped by version. No surprise breaking changes.
Detailed Error Feedback
All errors return structured JSON with field-specific codes and messages. Example: 422 UNMATCHED_LOAD
Self-Documenting Schema
View our OpenAPI schema or Swagger docs. Every endpoint is documented with sample input, response, and expected formats.
Where Our Data Comes From
The OSOW dataset is sourced directly from state DOT websites, legal rulebooks, published permit documents, and real carrier submissions. Every field is manually reviewed and tagged by state.
State DOT Rulebooks
Primary source for all dimensional limits, escort rules, and movement restrictions.
Permit Applications
Downloaded and scanned from each state, then parsed and structured by our validators.
Direct DOT Communication
When data is unclear or undocumented, we contact state offices directly and log responses.
Carrier Feedback
Verified submissions help us validate edge cases and expose inconsistencies in state documentation.
AI Consistency Scans
We use automated text scanning to flag field mismatches, gaps, and contradictions.
Weekly Update Schedule
Every state’s data is reviewed at least once per week, with instant updates for flagged changes.
Want to audit a specific state or field? We log update timestamps and changes to every field —see audit trail.
Plans for Teams of Any Size
Whether you’re a solo dispatcher or managing hundreds of permits per month, OSOW has a plan that fits your workflow.
2,000 API calls / month
- 🚀 Full permit matcher
- 📄 Auto PDF + Invoice exports
- 🔁 Webhook alerts
Enterprise API volume
- 🏛️ SLA & Audit Logs
- 📆 Weekly sync support
- 🛡️ Custom field access
What Teams Are Saying
Logistics leaders, permit agents, and dispatchers use OSOW to save hours, reduce errors, and simplify their workflows. Here’s what they’ve said.
“We used to spend 4–5 hours per permit just figuring out what states required. Now it's one API call and we’re done. Game changer.”
IronTrail Freight
“I didn't expect much from an API for oversize stuff, but OSOW is crazy polished. The documentation, the webhook system — it just works.”
PermitGenius
“We replaced 3 separate spreadsheets and 2 permit contractors using OSOW. Our cost per load dropped by nearly 30%.”
RoadWise Logistics
“It used to take us two days to prepare a 10-state route. Now our permit team finishes it in under an hour.”
FleetFast Dispatch
“We got our entire dev team unblocked by using OSOW. It’s the first logistics API I’ve used that feels modern.”
OversizeHub
Want to be featured? Send your feedback.
Frequently Asked Questions
Still wondering if OSOW is the right fit for your operation? Here are answers to the most common questions we get from carriers, brokers, and developers.
Even More Tools Under the Hood
OSOW isn’t just a lookup tool. It’s packed with features that handle edge cases, automate paperwork, and make your workflow faster than ever.
📁 CSV & ZIP Export
Download full permit bundles, route sets, or matched rule data in clean CSV format or multi-file ZIPs for archiving or compliance.
🧠 Smart Matcher
Our engine compares your load against historical permits and route rules — then ranks the best options with confidence scoring.
📝 Auto-Filled Forms
Generate permit-ready forms pre-filled with your load data, dimensions, carrier info, and escorts — customized by state requirements.
📡 Webhook Filters
Choose which event types you want to listen for — avoid noise and only get alerts for the rules, states, or thresholds that matter to you.
🛑 State Rule Validation
Every input is scanned against hard limits for each state. If your height, weight, or spacing is illegal, we’ll flag it before submission.
👥 Team Access
Invite team members to manage bundles, view invoice history, or access specific keys. Role-based permissions keep data secure.
Designed for Fast-Moving Teams
Whether you’re at a truck stop, in the office, or on a hotshot load at 6am, OSOW is built to work on the devices and timelines real logistics teams rely on.
Fully Mobile-Compatible
Every feature works perfectly on phones and tablets — no zooming, no janky forms.
Instant Load Feedback
See violations, match permits, and review fees without waiting for a call or email.
Built for Speed
Average endpoint response time is under 150ms. Your dispatcher won’t be waiting.
Quick Export Tools
Download CSVs, PDFs, or ZIPs directly to your device in seconds — no desktop required.
No Login Timeouts
Stay logged in throughout your workday. Designed for multi-tab, multi-tasking.
Readable in Sunlight
Contrast-tested UI and font scaling optimized for truck cab screens and phones.
Always Improving
OSOW is updated weekly based on state changes, customer feedback, and internal audits. Here’s a sample of recent updates from our changelog.
California Night Travel Rules Updated
Updated curfew fields and escort requirements based on latest DOT circular. Alert sent to subscribers.
Smart Matcher V2 Launched
Matcher now returns top 3 permits with confidence scores, matched fees, and escort flags.
Webhook Retry Logic Fixed
Webhooks now retry 3x on failure with exponential backoff. Affects Ultra + Pro tier subscribers.
Permit PDF Export v1.2
Improved formatting for escort sections + added job reference field to every generated document.
Dashboard Usage Graphs Live
Users can now view per-key usage trends and download monthly CSV exports from the /dashboard page.
Explore the Full API Schema
View our live OpenAPI explorer, test endpoints in Swagger UI, or import our full spec into Postman. No guesswork. No broken routes. Just clean documentation.
Ready to simplify oversize permit planning across all 50 states?
OSOW API gives you permit matching, rule validation, export tools, and webhook alerts — all in one system. Start in minutes. No contracts. No nonsense.
No credit card required. Cancel anytime.