Struct Workflow 

pub struct Workflow {

    pub name: String,
    pub version: u32,
    pub priority: Priority,
    pub unload: Unload,
    pub durable: Option<bool>,
    pub state: BTreeMap<String, StateDecl>,
    pub description: Option<String>,
    pub armed: bool,
    pub inputs_schema: Option<Value>,
    pub concurrency: Concurrency,
    pub key: Option<String>,
    pub tool: Option<WorkflowTool>,
    pub limits: WorkflowLimits,
    pub outputs_schema: Option<Value>,
    pub steps: BTreeMap<String, Step>,
    pub hash: String,
    pub definition: Value,
}

A parsed, validated workflow.

Fields

name: String

version: u32

priority: Priority

Scheduling weight under contention. low admissions shed one pressure level EARLIER (at warn, not just shed), and ready steps of higher-priority runs are scheduled first each tick. It is a tiebreak under scarcity, not a reservation.

unload: Unload

Retirement policy for live runs (unload: {policy, timeout}).

durable: Option<bool>

Durability class: Some(false) ⇒ runs of this workflow are memory-only (no checkpoints, gone after a restart — the fast path for recomputable work); Some(true) ⇒ durable even under store.durability.work: ephemeral. None in a freshly parsed document; the loader resolves it against the store’s default before the definition is armed.

state: BTreeMap<String, StateDecl>

Declared run variables: {key: {type, reducer}}.

Optional, and the point is to make concurrent writes a DECLARED policy instead of a heuristic. Without it the parser can only guess from the modes two racing writers happen to use; with it, the workflow states what a key is and how writes to it combine, and disagreement is a config error rather than a value that depends on completion order.

description: Option<String>

armed: bool

inputs_schema: Option<Value>

concurrency: Concurrency

key: Option<String>

The logical thing a run is ABOUT, rendered from the trigger payload ("{{payload.account_id}}").

Everything else in the runtime is keyed — breakers, rate buckets, start state, webhook dedup, step idempotency — but the run itself had no logical name, only an id. That is why per-entity serialization was not expressible: max_runs could count runs but not runs about the same account.

tool: Option<WorkflowTool>

Register this workflow in the tool registry as a first-class contract.

The shapes already match: a workflow carries a description, an input schema, an output schema and a definition hash, which is exactly a tool contract. What it adds over an MCP tool is everything the engine already has — a “tool call” that takes thirty minutes, survives a restart, and has retry, breaker, idempotency and a human gate INSIDE it. And it is strictly better for the trifecta fold: a subagent handed billing.refund spends its legs on one reviewed procedure instead of a whole server’s tool surface.

limits: WorkflowLimits

outputs_schema: Option<Value>

steps: BTreeMap<String, Step>

hash: String

SHA-256 of the canonical definition. A run pins the hash it started against, so a redefinition never changes the shape of work already in flight, and workflow.list can show whether two instances agree.

definition: Value

The definition as given (canonical JSON), for workflow.list/hash.

Implementations

impl Workflow

pub fn start_steps(&self) -> Vec<&Step>

pub fn step(&self, id: &str) -> Option<&Step>

pub fn dependents(&self, id: &str) -> Vec<&Step>

The steps that depend on id.

pub fn is_long_lived(&self) -> bool

Whether any start node makes this workflow long-lived: one that keeps firing — a timer, a schedule, a subscription, an inbound signal, event, A2A message or stream — rather than running once and finishing.

This decides daemon shape. An instance holding a long-lived workflow must not idle-exit, because the workflow’s whole purpose is to still be there when its trigger arrives.

pub fn topo_order(&self) -> Vec<String>

The step ids in a deterministic topological order (deps first).

Trait Implementations

impl Clone for Workflow

fn clone(&self) -> Workflow

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Workflow

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Workflow

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Workflow

fn eq(&self, other: &Workflow) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for Workflow

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Workflow