node

SUPPORT · function · Runtime value

Instantiate a node definition class once, injecting its id; graph validation stays in Workflow. Bind a named host method as run without renaming or manually binding the original object.

Import

TypeScript

import { node } from '@jangts/agent-core/support/decorators';

JavaScript

import { node } from '@jangts/agent-core/support/decorators';

Other public entry points:@jangts/agent-core/support/decorators.

Definition

Type parameters

Type parameter	Constraint	Default type
State	—	any
Result	—	unknown
App	—	any

Overload 1

node<State = any, Result = unknown, App = any>(id: string, options?: DecorationOptions): ClassDecoration<WorkflowNode<State, Result, App>>

Instantiate a node definition class once, injecting its id; graph validation stays in Workflow.

Type parameter	Constraint	Default type
State	—	any
Result	—	unknown
App	—	any

Parameter	Type	Passing	Description
id	string	Required	—
options	DecorationOptions | undefined	Optional	—

Optional shapes of Parameter options: choose one shape; required fields for each branch are listed separately.

Branch 1

undefined

Branch 2

Field	Type	Required	Description
ns	string | readonly string[] | undefined	Optional	Read-only. See the type definition and usage context.

Returns: ClassDecoration<WorkflowNode<State, Result, App>>.

Overload 2

node<State = any, Result = unknown, App = any>(id: string, options: MethodOptions<WorkflowNode<State, Result, App>, "run">): MethodDecoration<NonNullable<WorkflowNode<State, Result, App>["run"]>>

Bind a named host method as run without renaming or manually binding the original object.

Type parameter	Constraint	Default type
State	—	any
Result	—	unknown
App	—	any

Parameter	Type	Passing	Description
id	string	Required	—
options	MethodOptions<WorkflowNode<State, Result, App>, "run">	Required	—

Fields of options

Field	Type	Required	Description
description	string	Required	Read-only. Required explanation of what the node does; also used in diagnostics.
name	string | undefined	Optional	Read-only. Display name; defaults to id when omitted.
requires	readonly (keyof State & string)[] | undefined	Optional	Read-only. State keys that must be present before this node runs; enforced by the engine.
provides	readonly (keyof State & string)[] | undefined	Optional	Read-only. State keys this node is expected to produce; validated after run.
routes	readonly WorkflowRoute<State, Result, App>[]	Required	Read-only. Candidate successors, evaluated in order. A getter must be pure; registration reads it once.
report	((update: void | Readonly<Partial<State>>, context: NodeReportingContext) => WorkflowNodeReport) | undefined	Optional	Read-only. Optional application-reported detail, collected only when content logging is enabled.
startsRound	boolean | undefined	Optional	Read-only. Reserves a fresh round on entry. Use it for steps that may legitimately repeat; entering such a node when the round budget is exhausted fails with the configured exhausted error.
onErrorNodeId	string | undefined	Optional	Read-only. Node entered when run/provides/route fails; contract errors always propagate instead.
onErrorRouteId	string | undefined	Optional	Read-only. Route id reported with the recovery transition.
ns	string | readonly string[] | undefined	Optional	Read-only. See the type definition and usage context.

Returns: MethodDecoration<(state: Readonly<State>, context: WorkflowContext<App>) => void \| Partial<State> \| Promise<void \| Partial<State>>>.

Examples

• Workflow: nodes, routes, and partial state updates: Use a single node definition that actually participates in execution to show order, branches, error destinations, and end conditions together.
• Decorators: complete handlers and existing host methods: Classes construct definitions automatically; methods bind the real host. Outputs still use original define, constructor and bind contracts.

A single node completes the greeting

Beginner · Node.js

TypeScript

import { AgentCoreEngine, defineWorkflow, route } from '@jangts/agent-core/engine';

type State = { name: string; answer?: string };
const workflow = defineWorkflow<State, string>({
  id: 'greeting',
  nodes: [{
    id: 'greet', description: '根据本次姓名生成问候', startsRound: true,
    run: state => ({ answer: '你好，' + state.name }),
    routes: [route.deliver('answer')],
  }],
});
console.log(workflow.entryNodeId);
console.log(workflow.describe());

JavaScript

import { AgentCoreEngine, defineWorkflow, route } from '@jangts/agent-core/engine';
const workflow = defineWorkflow({
    id: 'greeting',
    nodes: [{
            id: 'greet', description: '根据本次姓名生成问候', startsRound: true,
            run: state => ({ answer: '你好，' + state.name }),
            routes: [route.deliver('answer')],
        }],
});
console.log(workflow.entryNodeId);
console.log(workflow.describe());

Add a validation stage without changing state or the run call

Configuration · Node.js

TypeScript

import { AgentCoreEngine, defineWorkflow, route } from '@jangts/agent-core/engine';
type State = { name: string; answer?: string; error?: string };
const workflow = defineWorkflow<State, string>({
  id: 'greeting',
  nodes: [
    { id: 'check', description: '检查姓名', startsRound: true,
      run: state => ({ error: state.name.trim() ? undefined : '姓名不能为空' }),
      routes: [route.toIfError('failure'), route.to('greet')] },
    { id: 'greet', description: '生成问候', provides: ['answer'],
      run: state => ({ answer: '你好，' + state.name }), routes: [route.deliver('answer')] },
    { id: 'failure', description: '返回校验提示', requires: ['error'], routes: [route.deliver('error')] },
  ],
});
console.log(await new AgentCoreEngine({ workflow }).run({ name: 'Ivan' }));

JavaScript

import { AgentCoreEngine, defineWorkflow, route } from '@jangts/agent-core/engine';
const workflow = defineWorkflow({
    id: 'greeting',
    nodes: [
        { id: 'check', description: '检查姓名', startsRound: true,
            run: state => ({ error: state.name.trim() ? undefined : '姓名不能为空' }),
            routes: [route.toIfError('failure'), route.to('greet')] },
        { id: 'greet', description: '生成问候', provides: ['answer'],
            run: state => ({ answer: '你好，' + state.name }), routes: [route.deliver('answer')] },
        { id: 'failure', description: '返回校验提示', requires: ['error'], routes: [route.deliver('error')] },
    ],
});
console.log(await new AgentCoreEngine({ workflow }).run({ name: 'Ivan' }));

The same node contract can be implemented by a class

Extension · Node.js

TypeScript

import { AgentCoreEngine, defineWorkflow, route } from '@jangts/agent-core/engine';
type State = { name: string; answer?: string };
class GreetingNode {
  readonly id = 'greet';
  readonly description = '根据姓名生成问候';
  readonly startsRound = true;
  readonly routes = [route.deliver('answer')];
  #prefix = '你好，';
  run(state: Readonly<State>) { return { answer: this.#prefix + state.name }; }
}
const workflow = defineWorkflow<State, string>({ id: 'greeting', nodes: [new GreetingNode()] });
console.log(await new AgentCoreEngine({ workflow }).run({ name: 'Ivan' }));

JavaScript

import { AgentCoreEngine, defineWorkflow, route } from '@jangts/agent-core/engine';
class GreetingNode {
    id = 'greet';
    description = '根据姓名生成问候';
    startsRound = true;
    routes = [route.deliver('answer')];
    #prefix = '你好，';
    run(state) { return { answer: this.#prefix + state.name }; }
}
const workflow = defineWorkflow({ id: 'greeting', nodes: [new GreetingNode()] });
console.log(await new AgentCoreEngine({ workflow }).run({ name: 'Ivan' }));

Related policy source

• Reference, reachability, and bounded-loop validation

Related definitions

• ClassDecoration
• DecorationOptions
• MethodDecoration
• WorkflowNode