LapViz for developers API v1

Build on lap timing data

A REST API for sessions, laps, sectors and telemetry, and open source libraries for timing. The data and the code the LapViz apps run on, open to your projects.

Get an API key API reference Guides
Join the LapViz Discord Questions, ideas and help from the team and the other developers
Terminal 
# Your latest sessions
curl -X POST https://www2.lapviz.com/api/session/search \
  -H "X-Api-Key: $LAPVIZ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "mine": true, "pageSize": 5 }'

# → 200 OK
{
  "sessions": [
    {
      "shareId": "9e8451",
      "circuit": { "name": "Karting de Mariembourg", ... },
      "best": "00:00:49.8120000",
      "laps": 18,
      "hasTelemetry": true
    }
  ],
  "totalRecords": 127
}

Start in three steps

  1. 1 Create an API key In Account › API keys. Choose read or read and write, and how long it lives. Create a key
  2. 2 Call the API Send the key in the X-Api-Key header. JSON in, JSON out, from any language. Quickstart
  3. 3 Explore the reference Every operation, with its parameters and schemas. Authorize once and try them live. API reference

The API

REST and JSON over HTTPS, described in OpenAPI 3: generate a client in the language you like.

Clients: .NET, Python, TypeScript OpenAPI description (JSON) Postman collection

What you can build

  • Dashboards and coaching tools Pull the laps, sectors and channels of your drivers into your own analysis, notebooks or reports.
  • Sync and back up Mirror a session library with the change feed and the LapViz files, incrementally.
  • Import from your logger Send the files of your logger or app: LapViz reads more than 20 formats and builds the sessions.
  • Lap timers Get the start/finish and sector lines of the circuits and time laps with LapViz.Telemetry.
  • Video overlays Export a session as subtitles or After Effects motion graphics, synchronised with the laps.
  • Team tools Manage the members, roles and invitations of your teams from your own tools.
  • Ask your sessions in an AI assistant Connect Claude, Cursor or VS Code to the LapViz MCP server and ask where the time goes, in plain words.

Open source

The timing logic of the LapViz apps, published under the MIT license. Contributions welcome.

LapViz.Telemetry

MIT .NET Standard 2.0 · .NET 8 · .NET 9

The .NET library that knows what a lap is: sessions, drivers, laps and sectors, GPS line crossings with interpolation, predictive delta, theoretical and rolling best laps, more than 190 built-in circuits, file readers and writers. The exact code behind every LapViz app, tested on recorded sessions. 

dotnet add package LapViz.Telemetry
Source on GitHub NuGet Issues

LapViz.LiveTiming

Publish and follow live timing sessions from your own app. In the same repository.

NuGet

LapViz file format

An open format (.lvz): a ZIP with a JSON manifest and the samples in columns. Read and written by LapViz.Telemetry.

Supported formats

Community and support

Questions, ideas, a format to support, something you built? Talk to the team and to the other developers.

Built with LapViz: the projects of the community Changelog (RSS)

Good to know

Privacy first A key sees exactly what its owner sees on the site. Private sessions stay private.
600 requests a minute Per account, with RateLimit headers on every response. Limits
Stable v1 Breaking changes are announced 6 months ahead. Versioning
Found a vulnerability? Tell us privately first. Responsible disclosure