Trait StateGraph 

pub trait StateGraph: Send + Sync {
    type State: GraphState;
    type Compiled: CompiledGraph<Self::State>;

    // Required methods
    fn new(id: impl Into<String>) -> Self;
    fn add_node(
        &mut self,
        id: impl Into<String>,
        node: Box<dyn NodeFunc<Self::State>>,
    ) -> &mut Self;
    fn add_edge(
        &mut self,
        from: impl Into<String>,
        to: impl Into<String>,
    ) -> &mut Self;
    fn add_conditional_edges(
        &mut self,
        from: impl Into<String>,
        conditions: HashMap<String, String>,
    ) -> &mut Self;
    fn add_parallel_edges(
        &mut self,
        from: impl Into<String>,
        targets: Vec<String>,
    ) -> &mut Self;
    fn set_entry_point(&mut self, node: impl Into<String>) -> &mut Self;
    fn set_finish_point(&mut self, node: impl Into<String>) -> &mut Self;
    fn add_reducer(
        &mut self,
        key: impl Into<String>,
        reducer: Box<dyn Reducer>,
    ) -> &mut Self;
    fn with_config(&mut self, config: GraphConfig) -> &mut Self;
    fn id(&self) -> &str;
    fn compile(self) -> AgentResult<Self::Compiled>;
}

State graph builder trait

Defines the interface for building stateful workflow graphs. Implementations should provide a fluent API for constructing graphs.

Example

use mofa_kernel::workflow::{StateGraph, START, END};

let graph = StateGraphImpl::<MyState>::new("my_workflow")
    // Add reducers for state keys
    .add_reducer("messages", Box::new(AppendReducer))
    .add_reducer("result", Box::new(OverwriteReducer))
    // Add nodes
    .add_node("process", Box::new(ProcessNode))
    .add_node("validate", Box::new(ValidateNode))
    // Add edges
    .add_edge(START, "process")
    .add_edge("process", "validate")
    .add_edge("validate", END)
    // Compile
    .compile()?;

Required Associated Types

type State: GraphState

The state type for this graph

type Compiled: CompiledGraph<Self::State>

The compiled graph type produced by this builder

Required Methods

fn new(id: impl Into<String>) -> Self

Create a new graph with the given ID

fn add_node( &mut self, id: impl Into<String>, node: Box<dyn NodeFunc<Self::State>>, ) -> &mut Self

Add a node to the graph

Arguments

• id - Unique node identifier
• node - Node function implementation

fn add_edge( &mut self, from: impl Into<String>, to: impl Into<String>, ) -> &mut Self

Add an edge between two nodes

Arguments

• from - Source node ID (use START for entry edge)
• to - Target node ID (use END for exit edge)

fn add_conditional_edges( &mut self, from: impl Into<String>, conditions: HashMap<String, String>, ) -> &mut Self

Add conditional edges from a node

Arguments

• from - Source node ID
• conditions - Map of condition names to target node IDs

Example

graph.add_conditional_edges("classify", HashMap::from([
    ("type_a".to_string(), "handle_a".to_string()),
    ("type_b".to_string(), "handle_b".to_string()),
]));

fn add_parallel_edges( &mut self, from: impl Into<String>, targets: Vec<String>, ) -> &mut Self

Add parallel edges from a node

Arguments

• from - Source node ID
• targets - List of target node IDs to execute in parallel

fn set_entry_point(&mut self, node: impl Into<String>) -> &mut Self

Set the entry point (equivalent to add_edge(START, node))

fn set_finish_point(&mut self, node: impl Into<String>) -> &mut Self

Set a finish point (equivalent to add_edge(node, END))

fn add_reducer( &mut self, key: impl Into<String>, reducer: Box<dyn Reducer>, ) -> &mut Self

Add a reducer for a state key

Arguments

• key - State key name
• reducer - Reducer implementation

fn with_config(&mut self, config: GraphConfig) -> &mut Self

Set the graph configuration

fn id(&self) -> &str

Get the graph ID

fn compile(self) -> AgentResult<Self::Compiled>

Compile the graph into an executable form

This validates the graph structure and prepares it for execution.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors