Trait NodeImpl 

pub trait NodeImpl:
    Send
    + Sync
    + Debug
    + 'static {
    type Config: DeserializeOwned + Send + Sync + Debug;

    const NODE_TYPE: Option<NodeType> = None;
    const NODE_TAGS: &'static [NodeTag] = _;
    const CRATE_NAME: Option<&'static str> = None;
    const DESCRIPTION: &'static str = "";
    const DEFAULT_RUN_TARGET: &'static str = "robot";
    const CATALOG_TAGS: &'static [&'static str] = _;

    // Required methods
    fn init<'async_trait>(
        config: Self::Config,
    ) -> Pin<Box<dyn Future<Output = Result<Self>> + Send + 'async_trait>>
       where Self: Sized + 'async_trait;
    fn run<'life0, 'life1, 'async_trait>(
        &'life0 mut self,
        ctx: &'life1 Context,
    ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;

    // Provided methods
    fn shutdown<'life0, 'async_trait>(
        &'life0 mut self,
    ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait { ... }
    fn health_check<'life0, 'async_trait>(
        &'life0 self,
    ) -> Pin<Box<dyn Future<Output = HealthStatus> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait { ... }
    fn health_diagnostics(&self) -> Option<HashMap<String, String>> { ... }
    fn preflight(&self) -> Result<()> { ... }
}

Provided Associated Constants

const NODE_TYPE: Option<NodeType> = None

const NODE_TAGS: &'static [NodeTag] = _

const CRATE_NAME: Option<&'static str> = None

Crate name as it appears in Cargo.toml (e.g. "mecha10-nodes-camera").

None (the default) means this node isn’t meant to be scaffolded via mecha10 add – e.g. test/example nodes, or any node that hasn’t opted into registration yet. This is also the gate crate::register_node! checks: a node whose CRATE_NAME is None registers no crate::node_registry::NodeDescriptor at all, regardless of what its other registration-related consts are set to.

const DESCRIPTION: &'static str = ""

Human-readable one-line description of what this node does, surfaced by a catalog consumer (e.g. mecha10 add <node>’s listing). Empty by default.

const DEFAULT_RUN_TARGET: &'static str = "robot"

Default mecha10 add/run target for this node (e.g. "robot" vs. a simulator-only target). Defaults to "robot".

const CATALOG_TAGS: &'static [&'static str] = _

Free-form catalog search tags (e.g. &["camera", "video", "streaming"]), distinct from NODE_TAGS (a NodeTag enum used for health-reporting capability tags). Surfaced by a catalog consumer (e.g. mecha10 add <node>’s search/filtering). Empty by default.

Required Associated Types

type Config: DeserializeOwned + Send + Sync + Debug

Required Methods

fn init<'async_trait>( config: Self::Config, ) -> Pin<Box<dyn Future<Output = Result<Self>> + Send + 'async_trait>>

where Self: Sized + 'async_trait,

Initialize the node with the given configuration.

This is called once when the node starts. Use this to:

• Load configuration
• Initialize resources (models, connections, etc.)
• Validate prerequisites

Errors

Return an error if initialization fails. The node will not start.

fn run<'life0, 'life1, 'async_trait>( &'life0 mut self, ctx: &'life1 Context, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Main execution loop for the node.

This is where your node’s business logic lives. Typical patterns:

• Subscribe to topics and process messages
• Run periodic tasks
• Publish results

This method should run indefinitely until:

• The context is cancelled (shutdown requested)
• An unrecoverable error occurs

Errors

Return an error if the node encounters an unrecoverable error. The node will transition to Error state and shutdown.

Provided Methods

fn shutdown<'life0, 'async_trait>( &'life0 mut self, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Graceful shutdown hook.

Called when the node is shutting down. Use this to:

• Close connections
• Flush buffers
• Save state
• Release resources

The default implementation does nothing.

Errors

Errors during shutdown are logged but don’t prevent shutdown.

fn health_check<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = HealthStatus> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Health check for monitoring.

Called periodically to check node health. Use this to:

• Report current state
• Check resource usage
• Validate connections

The default implementation returns healthy status.

fn health_diagnostics(&self) -> Option<HashMap<String, String>>

Extra diagnostic key/value pairs to attach to this node’s health report (surfaced on the wire as crate::messages::system::HealthStatus::diagnostics).

Separate from health_check()’s HealthStatus (which has a fixed shape shared by every node) so a node can report open-ended, node-specific data – e.g. video-streamer reports which camera_id(s) it’s actually streaming, since that’s a per-camera identity distinct from this node’s own node_id/instance_id and the dashboard needs it to pair WebRTC signaling correctly (see packages/nodes/video-streamer/src/lib.rs’s impl).

The default implementation reports nothing.

fn preflight(&self) -> Result<()>

Node-specific pre-run content check.

This is the “prerun” layer that catches a bad node config before the node’s main loop starts, rather than crashing deep inside run() – e.g. a camera device path that doesn’t exist, a model file that was never downloaded, or two GPIO pins wired to the same physical pin.

Called once, after init() has already produced a fully-typed (and, per crate::config::Validate, schema/shape-validated) Self, and before run() starts. Unlike Validate::validate() – which only sees the raw deserialized config and runs during config loading – preflight() runs on the initialized node, so it can also check state derived during init() (e.g. a resolved file path) rather than just raw config fields.

The default implementation does nothing, so opting in is non-breaking for every existing NodeImpl.

Errors

Return an error with an actionable message (see node-runner’s preflight.rs for the established convention: a ❌ header naming what failed, followed by numbered remediation steps) if the node should not start. The node will not run.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors