CoreStep

CORE · type · Type contract

One loop iteration. Must be re-entrant: the same step object runs every round.

Import

TypeScript

import type { CoreStep } from '@jangts/agent-core/engine';

JavaScript

/** @typedef {import('@jangts/agent-core/engine').CoreStep} CoreStep */

Other public entry points:@jangts/agent-core, @jangts/agent-core/engine, @jangts/agent-core/types, @jangts/agent-core/structs.

Definition

type CoreStep<Result> = (
  roundIndex: number,
  context: ExecutionContext & import('../debug.js').NodeReportingContext & CacheContext,
) => MaybePromise<StepOutcome<Result>>;

Type parameters

Type parameter	Constraint	Default type
Result	—	—

Call

CoreStep(roundIndex: number, context: ExecutionContext & import("../debug.js").NodeReportingContext & CacheContext): MaybePromise<StepOutcome<Result>>

Parameter	Type	Passing	Description
roundIndex	number	Required	—
context	ExecutionContext & NodeReportingContext & CacheContext	Required	—

Fields of context

Field	Type	Required	Description
logger	SubFlowLog | undefined	Optional	Read-only. Explicit optional recorder for this operation; never inferred from diagnostics.
signal	AbortSignal	Required	Read-only. Non-optional cancellation signal; never undefined once execution has started.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Diagnostic scope of the enclosing call, when recording is enabled.
report	(update: import("./execution/workflow.js").WorkflowNodeReport) => void	Required	Reports progress for the active node; Core supplies the execution identity.
createSubFlowLogger	() => SubFlowLogger	Required	Bound to this context and owned by runtime; repeated calls in one visit return the same instance.
cache	NodeCache	Required	Read-only. See the type definition and usage context.
agentCache	NodeAgentCache | undefined	Optional	Read-only. See the type definition and usage context.

Returns: MaybePromise<StepOutcome<Result>>.

Awaited value: StepOutcome<Result>.

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

Branch 1

Field	Type	Required	Description
type	"continue"	Required	Read-only. See the type definition and usage context.

Branch 2

Field	Type	Required	Description
type	"complete"	Required	Read-only. See the type definition and usage context.
value	Result	Required	Read-only. See the type definition and usage context.

Examples

• Agent: run first, then bind tools and dependencies step by step: The Engine executes a bounded loop; after a Workflow is bound, each run only receives the data that changed in state.

A single ordinary step is enough to run

Beginner · Node.js

TypeScript

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

const agent = new AgentCoreEngine<string>();
const answer = await agent.run(() => ({ type: 'complete', value: '你好，Core' }));
console.log(answer);

JavaScript

import { AgentCoreEngine } from '@jangts/agent-core/engine';
const agent = new AgentCoreEngine();
const answer = await agent.run(() => ({ type: 'complete', value: '你好，Core' }));
console.log(answer);

Add an explicit Workflow and still call run

Configuration · 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')],
  }],
});

const agent = new AgentCoreEngine({ workflow });
console.log(await agent.run({ name: 'Ivan' }));
console.log(await agent.run({ name: '访客' }));

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')],
        }],
});
const agent = new AgentCoreEngine({ workflow });
console.log(await agent.run({ name: 'Ivan' }));
console.log(await agent.run({ name: '访客' }));

Related policy source

• Execution implementation of the bounded loop, commit, and cancellation

Related definitions

• CacheContext
• ExecutionContext
• MaybePromise
• NodeReportingContext
• StepOutcome