Message types

Cerulion ships ROS 2 compatible message types in the native_ros2_messages crate, generated from upstream .msg definitions at build time. The current build carries 254 messages across 22 packages, so most robotics pipelines never need a custom schema. Import a type from its package:

use native_ros2_messages::sensor_msgs::Image;

Reference it in graph YAML by qualified name (sensor_msgs/Image); the pkg::Type form is normalized to pkg/Type. List everything available on your build, grouped by package:

cerulion schema list

Packages

Package	Types	Representative types
`action_msgs`	3	`GoalInfo`, `GoalStatus`, `GoalStatusArray`
`autoware_perception_msgs`	6	Perception objects and predicted trajectories.
`autoware_planning_msgs`	5	Planning trajectories and path shapes.
`builtin_interfaces`	2	`Time`, `Duration`
`control_msgs`	39	`JointTrajectoryControllerState`, `DynamicJointState`, `JointJog`, `PidState`, `GripperCommand`
`diagnostic_msgs`	3	`DiagnosticArray`, `DiagnosticStatus`, `KeyValue`
`geometry_msgs`	32	`Point`, `Pose`, `PoseStamped`, `Quaternion`, `Transform`, `Twist`, `Vector3`
`grid_map_msgs`	2	`GridMap`, `GridMapInfo`
`moveit_msgs`	46	`CollisionObject`, `AttachedCollisionObject`, `DisplayTrajectory`, `Constraints`, `Grasp`
`nav_msgs`	5	`Odometry`, `Path`, `OccupancyGrid`, `MapMetaData`, `GridCells`
`object_recognition_msgs`	6	`RecognizedObject`, `RecognizedObjectArray`, `ObjectInformation`
`octomap_msgs`	2	`Octomap`, `OctomapWithPose`
`radar_msgs`	4	`RadarReturn`, `RadarScan`, `RadarTrack`, `RadarTracks`
`sensor_msgs`	27	`Image`, `Imu`, `LaserScan`, `JointState`, `PointCloud2`, `CameraInfo`, `CompressedImage`, `NavSatFix`
`shape_msgs`	4	`Mesh`, `MeshTriangle`, `Plane`, `SolidPrimitive`
`statistics_msgs`	3	`MetricsMessage`, `StatisticDataPoint`, `StatisticDataType`
`std_msgs`	30	`Header`, `String`, `Bool`, `Empty`, `ColorRGBA`, the numeric scalars, and the `*MultiArray` family
`tf2_msgs`	2	`TFMessage`, `TF2Error`
`trajectory_msgs`	4	`JointTrajectory`, `JointTrajectoryPoint`, and their multi-DOF forms
`unique_identifier_msgs`	1	`UUID`
`vision_msgs`	16	`Detection2D`, `Detection2DArray`, `Detection3D`, `BoundingBox2D`, `ObjectHypothesisWithPose`
`visualization_msgs`	12	`Marker`, `MarkerArray`, `ImageMarker`, the interactive-marker family

A bare type name that exists in several packages — Pose2D is in both geometry_msgs and vision_msgs — must be qualified. The CLI errors and lists the candidates rather than guessing.

ROS 2 to Rust type mapping

ROS 2 type	Rust type
`bool`	`bool`
`byte` / `char` / `uint8`	`u8`
`int8`	`i8`
`uint16` / `int16`	`u16` / `i16`
`uint32` / `int32`	`u32` / `i32`
`uint64` / `int64`	`u64` / `i64`
`float32` / `float64`	`f32` / `f64`
`string`	UTF-8 string, read as `Result<&str, _>`
`T[]`	dynamic array, read as `&[T]`

Fixed and variable fields

Fixed-size fields are read and written as plain fields. Variable-length fields (string, T[]) are read through an accessor method and written with the same plain assignment:

use native_ros2_messages::sensor_msgs::Image;

// in tick(), with `#[output] image: Image`
self.image.height = 480;                 // fixed field
self.image.width = 640;
self.image.encoding = "rgb8";            // variable field — same assignment syntax
self.image.header.frame_id = "camera";   // nested field
self.image.data = &frame_bytes[..];      // variable field from a slice

// in tick(), with `#[input(trigger)] scan: LaserScan`
let closest = self.scan.ranges().iter().copied().fold(f32::MAX, f32::min);
let frame = self.scan.header.frame_id()?;

Variable-length output fields have one extra requirement: a tick that publishes a variable-schema message must write every variable field, at every nesting depth, or the frame is discarded with a loud error. For large payloads, fill_from writes straight into the shared-memory destination — see the node macro reference.

Defining your own

When no built-in type fits, define a workspace schema:

cerulion schema create Detections

The YAML format is in Graph and schema files. Workspace schemas resolve before built-in messages, so a bare name you define shadows a built-in one (with a warning).

Get started

Concepts

Guides

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Reference

Community

Packages

ROS 2 to Rust type mapping

Fixed and variable fields

Defining your own

​Packages

​ROS 2 to Rust type mapping

​Fixed and variable fields

​Defining your own

Packages

ROS 2 to Rust type mapping

Fixed and variable fields

Defining your own