Welcome to the Waltti Developers’ Portal
This site is developed and operated by TVV lippu- ja maksujärjestelmä Oy (LMJ), the Helsinki Regional Transport Authority (HSL) and the others 20 public transport urban regions, which all are the owners of LMJ.
LMJ is an IT services and procurement company which provides ticketing, payment and transport information system services to competent public transport authorities.
You can find information about our projects and APIs. Many projects offer open APIs that are available for everyone to use and you can generate new services on top of these APIs.
This is a great opportunity for us to collaborate with developers and startups and expand services relating to the organization of public transport we offer our customers.
Get in touch?