Record once, read forever.

At Foxglove, we build our ecosystem around a few simple principles, one being: record once, read forever. At the center of this is MCAP, our open source, efficient, and forward-compatible container format for multimodal data. Paired with the Foxglove SDK, MCAP ensures that the data you capture today will stay usable, portable, and easy to analyze for years to come.

Compatibility by design.

The MCAP format was designed from day one to be forward-compatible and durable. Since its initial release, it has remained stable—we’ve made no breaking changes, and we never will. This makes it a reliable foundation for any long-term logging and analysis workflow.

Schema-embedded, not schema-dependent.

Robotics workflows use binary messages to reduce overhead for runtime logging. As requirements evolve, so do these binary messages. Maintaining a reliable way to read historic data is crucial for reviewing past logs and continuously learning from data.

Unlike ad-hoc logging setups where a schema change or tooling update silently breaks your logs, MCAP files include self-contained metadata and message definitions. This enables forever decoding and reading of messages, even if the original publisher code is long gone. Whether it is a version of Foxglove released tomorrow or a script you write five years from now, the MCAP file has everything it needs to parse and interpret the data.

The Foxglove SDK builds on MCAP for its choice of recording, making it well-suited for recording what your robots did and accessing this information forever, regardless of how your software changes.

Why does it matter?

In real-world robotics deployments, data often outlives code. You might replace your stack three times in the lifespan of a robot fleet. But your logs are the only window you have into the past. Whether you're reproducing a field failure or benchmarking a new planner, you can't afford to be locked out of your history.

MCAP is the answer to that. It ensures your telemetry remains useful and accessible across versions, platforms, and time.

So go ahead: log everything. Instrument your stack. Record the weird cases. Store the raw bytes. You never know what insight you'll need to dig up years from now.

The contract is simple: if you record an MCAP today, you can read it forever.

Head to the Foxglove docs to get started with the Foxglove SDK and also explore mcap.dev tooling.