kapa.energy
From the creators of OpenF1 Become a design partner

The open-source API
for home batteries

Connect, monitor, and control residential batteries through their manufacturers’ clouds. One consistent API. No extra hardware.

Become a design partner View on GitHub

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What we're building

Every battery. One interface.

Energy products should focus on what to do with a battery, not spend months figuring out how to talk to it.

Battery telemetry

State of charge, power, energy, and device status in one predictable data model.

Remote control

Set operating modes, schedules, and power targets when supported by the manufacturer.

Cloud-to-cloud

Use official manufacturer APIs where possible and documented integrations elsewhere.

Developer-first

A clean REST API, consistent capabilities, useful errors, and documentation you actually want to read.

Safety by design

Explicit device capabilities, revocable access, command tracking, and guardrails for physical hardware.

Open source

Transparent integration logic, community contributions, and a foundation anyone can build upon.

Coverage and control depend on each manufacturer; no universal compatibility is claimed.

Why Kapa

Infrastructure you can read, run and rely on.

Connecting to battery clouds shouldn’t mean betting your product on a black box.

  1. See exactly what happens

    Every integration is open source. When your platform sends a command to a battery in someone’s home, you can read exactly how that command is translated and tracked. Nothing is hidden between your code and the hardware.

  2. No lock-in, by design

    Use the hosted API or run it yourself. Your integration layer stays yours, even if your plans change, or ours do.

  3. Know what every battery can do

    Each device exposes its capabilities up front: what you can read, what you can control, and what the manufacturer doesn’t allow. You know before you dispatch, not after a command silently fails.

  4. Coverage that grows with the community

    Integrations are built and validated by the people who own the hardware and the teams who depend on it. A fix doesn’t have to wait for someone else’s roadmap.

A familiar philosophy

From OpenF1
to open energy.

OpenF1 made complex racing data accessible through a simple, well-documented open-source API. Kapa is a new project from the same creators, bringing that developer-first approach to residential batteries.

Different industry. Same belief: great infrastructure should be transparent, reliable, and a pleasure to build with.

Discover OpenF1
F1OpenF1
Formula 1 data
Open-source API · Established project
Same creators. Same principles.
kkapa.energy
Residential energy
Open-source API · In development
The team

Meet the founders

One built open infrastructure that developers rely on. The other has built and sold a company in a regulated market.

Bruno Godefroy

Bruno Godefroy

Co-founder

Bruno created OpenF1, the open-source API that turned live Formula 1 data into something any developer can build on. He’s also a founding engineer at Tilt Energy, a startup that connects buildings and devices, including home batteries, so they can be paid for helping the grid. Kapa brings the two together: OpenF1’s developer-first approach, applied to a problem energy companies like Tilt face every day.

LinkedIn
Olivier Rull

Olivier Rull

Co-founder

Olivier is a serial entrepreneur who makes complicated consumer services simple. He co-founded Domos Kit, which let people sort out their internet, energy and home insurance contracts in a few clicks when moving house. He then co-founded Caravel, a sustainable retirement savings platform for the self-employed, which raised €1.5M in 2022 and was acquired by Indexa Capital in 2024.

LinkedIn
Build Kapa with us

The best APIs are built together.

We’re taking 3 design partners for Q1 2027.

Building an EMS, VPP, or another energy product? Help shape the integration layer your product needs.

What you get

  • Free access during beta
  • A long-term discount
  • Priority on the manufacturers you need
  • A direct channel to the founders
  • Real influence on the API design