---
id: mcap-ros1-support
version: "0.7.4"
license: unclear
license_treatment: permissive
maintenance: active
---

# mcap-ros1-support — ROS1 support for the Python MCAP library

License: permissive · Maintenance: active · Downloads: 93.7K/mo

## What it is and what it does

mcap-ros1-support bridges ROS1 and the MCAP file format by providing Python APIs to read and write ROS1 messages in MCAP files. MCAP is a container format for time-series data, and this package adds the ROS1-specific serialization layer needed to work with ROS1 message types within that container.

The package is built on top of the mcap library and depends on pyyaml for configuration handling. It exposes a reader interface for iterating over ROS1 messages stored in MCAP files and a writer interface for serializing ROS1 messages into new MCAP files. This is useful for robotics workflows where you need to log, replay, or analyze ROS1 sensor and control data in a standardized, language-agnostic format.

Use it for:

- Log ROS1 sensor data (camera, lidar, IMU) to MCAP files for offline analysis and replay
- Convert ROS1 bag files or live topics to MCAP format for interoperability with non-ROS tools
- Read and deserialize ROS1 messages from MCAP files in Python for data processing pipelines
- Archive robot telemetry and control messages in a portable, timestamped format

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Adds ROS1 message serialization and deserialization support to the MCAP file format, enabling reading and writing of ROS1 data in MCAP files.

Yes. The package is actively maintained, has no known vulnerabilities, uses a permissive MIT license, and carries low install friction. Install it if you need to work with ROS1 data in MCAP format; skip it if you have no ROS1 integration requirement.

## Install

pip install mcap-ros1-support
uv add mcap-ros1-support
poetry add mcap-ros1-support

## Installing mcap-ros1-support

Before you install: Low friction install with only two runtime dependencies (mcap and pyyaml). Package is actively maintained with recent commits and no known vulnerabilities.

License in practice: MIT license permits commercial and private use with minimal restrictions; you may use, modify, and distribute this package freely provided you include the license notice.

Quickstart:

pip install mcap-ros1-support

from mcap_ros1.reader import read_ros1_messages
for msg in read_ros1_messages("my_data.mcap"):
    print(f"{msg.topic}: {msg.ros_msg}")

Verify before relying:

- Whether ROS1 message definitions must be pre-installed or discoverable on the system for reading to work
- Performance characteristics when handling large MCAP files or high-frequency message streams

## Package facts

- License: not declared (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 93.7K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

ros1 mcap file support, read write ros1 messages, mcap ros1 serialization, ros1 data logging format, mcap file ros integration, ros1, mcap, robotics

[View on SkillFed](https://skillfed.io/packages/mcap-ros1-support) · [View on PyPI](https://pypi.org/project/mcap-ros1-support/)