Bring your own agent to Le Mans Ultimate.
LMU Harness runs on your machine and reads the logs the game already writes. Claude Code, Codex, Cursor or any MCP client works the studio with you over a local MCP server.
- sessions analysed
- 117
- tracks
- 15
One lap, two drivers
Scroll. The lap drives with you.
get_coach_report
T2 · +0.235 s
Apex 166 km/h against the leader's 180 km/h. Same braking point, less minimum speed.
Delta
+0.000s
km
0.00
You / Leader
226/227
Speed (km/h)
Delta to leader (s)
- T1 +0.031
- T2 +0.235
- T3 +0.048
- T4 +0.021
- T5 +0.033
- T6 +0.027
- T7 +0.036
Numbers from a simulated lap: real grip, braking and traction, stylised track.
From the podium to the braking point.
Everything comes from files Le Mans Ultimate already writes. Nothing leaves your machine.
3D race replay
The whole race rebuilt from the game replay. TV, onboard and chase cameras, a live timing tower and inferred flags.
Lap against lap
Put your lap next to any driver’s on the same track, from any session, and read the delta corner by corner.
Telemetry
Speed, throttle, brake, gear, rpm and steering across the lap. Zoom into any stretch.
Track map
The real layout with official corner numbers, synced to the telemetry cursor.
Results
Classification, laps and sectors for every driver, in timing-screen colours: purple overall best, green personal best.
Coach
Where you lose time to the class best, your theoretical lap, stint consistency and fuel per lap.
Bring your own agent.
The harness runs an MCP server next to the studio. Your agent reads the same sessions, laps and telemetry you do, and opens screens for you while you look.
- Every tool, locally
- Sessions, laps, telemetry, lap comparison, race events and the coach report. On your machine the agent can also import logs and save laps.
- It drives the studio
- open_in_ui opens a session or the 3D race replay in your browser, so you both look at the same corner.
- Your files stay put
- Logs are read from disk. No account, no upload, no server in between.
- WebMCP in the browser
- In Chrome the browser’s own agent works the studio too: opens a session, the replay or a lap comparison.
You: Where am I losing time at Sebring?
get_coach_reportSebring · GT3 race, 12 October
Mostly in sector 1. Your best S1 is 0.476 s off the GT3 class best, and sector 3 gives up another 0.144 s.
Your best sectors add up to 2:04.246, 0.261 s quicker than your best lap. Clean laps vary by 2.39 s, so start with repeatable brake points in sector 1.
- Sector 1
- +0.476
- Sector 3
- +0.144
- Best lap
- 2:04.507
- Theoretical
- 2:04.246
Point your agent at the local MCP
$ claude mcp add lmu -- bun $PWD/apps/mcp/src/main.tsRun it inside the lmu-harness folder. Claude Code also picks up the repo’s .mcp.json on its own.
From the track to your agent.
Race
Drive Le Mans Ultimate as usual. The game saves the result, your telemetry and a replay of every car.
Run
The harness runs on your machine. Its CLI watches the game folders and picks up each new session.
Ask
Open the session in the studio, or ask your agent. Both go through the same tools.
Install locally
Three steps. The game runs on Windows; the harness runs on Windows, macOS or Linux.
Needs Bun 1.3, Node 22 or newer, and git.
Fair Source · FSL-1.1-MIT, becomes MIT after 2 years.
Source on GitHub1Get the code
$ git clone https://github.com/fernandoeeu/lmu-harness$ cd lmu-harness$ bun install
2Start the studio
$ bun run devOpens at http://localhost:3000.
3Send your sessions
$ bun apps/cli/src/main.ts watchOn the PC that runs the game. Use submit instead of watch to send once. Game on another PC? Add --url http://<this machine>:3000.
- Just looking? See live demo