Building the Future of Transit Data: A First Look at MTD API V3

At MTD, we have a long and rich history of providing high-quality transit data to the public. From being among the first agencies in North America to publish real-time passenger information to launching our first Open API in 2010, we have consistently looked for ways to innovate how our riders interact with our service.

Today, we are excited to invite you to help us write the next chapter of that history. We are officially rolling out a preview version of MTD API Version 3.0, and we want your feedback to help us refine it.

Why a New API?

The code base for our current API is over 15 years old—a lifetime in the world of software. While it has served us well, it has become difficult to update or maintain it in a meaningful way. Version 3 is a ground-up, modern rewrite. By moving to a shared, modern infrastructure, we can ensure that our real-time data remains consistent across all platforms while reducing long-term maintenance costs.

What’s Changing?

We’ve built this new version to better reflect modern development standards and real-world use cases. Key updates include:

  • A New Home: All developer resources have moved to a brand-new website: mtd.dev
  • Interactive Documentation: We’ve integrated Swagger UI, which allows developers to browse documentation and test API calls directly in their browser.
  • Developer Tools: To speed up the development process, MTD is providing official NPM packages, including TypeScript types and a strongly typed API client.
  • Updated Licensing: We’ve introduced a new License Agreement that distinguishes between the License for Use and the License for Distribution.

More Than Just Apps

While we love seeing third-party apps, our API supports the community in many other ways. It is used every semester by the University of Illinois Computer Science students for coursework, by Urban Planning researchers to improve the transit industry, and by hobbyists building personal departure signs or Alexa skills.

How to Get Involved

Your “extra set of eyes” helps us maintain a culture of data discipline and accuracy. To participate in the preview:

  1. Sign Up: Visit dev/account to create a new account. Please note that old API keys will not carry over.
  2. Test & Build: Explore the new structure and see how it works with your projects.
  3. Send Feedback: We are collecting feedback via email at contact@mtd.dev.

We plan to keep this preview period open through the end of July as we prepare for a full launch near the beginning of the new service year in August. We look forward to hearing your thoughts and seeing what you create!