AgentModelRuntime

CORE · type · Type contract

The subset of a runner an engine may drive; kept small so the App can supply it.

Import

TypeScript

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

JavaScript

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

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

Definition

Type: AgentModelRuntime

Type expression

type AgentModelRuntime = Pick<
  ModelRunner,
  'invoke' | 'prepare' | 'execution' | 'remainingCalls' | 'callCount' | 'totalCallCount'
>;

Field structure

Field	Type	Required	Description
invoke	{ (request: string): Promise<ModelResult<string>>; <Result>(request: ModelCallRequest<never> & { readonly prepared: PreparedModelCall<Result>; }): Promise<ModelResult<Result>>; (request: ModelCallRequest<never>): Promise<ModelResult<string>>; <Result>(request: ModelCallRequest<ModelTransportDefinition<Result>> & { transport: ModelTransportDefinition<Result>; }): Promise<ModelResult<Result>>; <const Id extends string>(request: ModelCallRequest<Id> & { readonly transport: Id; }): Promise<ModelResult<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>>; (request: ModelCallRequest<string | ModelTransportDefinition<unknown>>): Promise<ModelResult<unknown>>; }	Required	Invoke one model call. Named and shorthand input share the same lifecycle: validation, measurement, budget charge, streaming, commit. A caller-supplied signal only shortens the call lifetime. Invoke a prepared call whose settings cannot be replaced. Invoke with the default transport and a plain-text result. Invoke with a transport instance supplied at the call site. Invoke with a transport id registered on this runner. Invoke without narrowing the transport type.
prepare	{ (request?: import("../structs/model/runtime.js").ModelPrepareRequest<never>): import("../structs/model/runtime.js").PreparedModelCall<string>; <Result>(request: ModelPrepareRequest<ModelTransportDefinition<Result>> & { readonly transport: ModelTransportDefinition<Result>; }): PreparedModelCall<Result>; <const Id extends string>(request: ModelPrepareRequest<Id> & { readonly transport: Id; }): PreparedModelCall<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>; (request: import("../structs/model/runtime.js").ModelPrepareRequest<string | ModelTransportDefinition>): import("../structs/model/runtime.js").PreparedModelCall; }	Required	Prepare a call and measure it before invocation. A prepared call is single-use and bound to the stage, output tokens and transport it was measured with; invoke rejects any attempt to replace those settings. Prepare a call for a transport instance supplied at the call site. Prepare a call for a transport id, typed by the runner's registered transports. Prepare a call without narrowing the transport type.
execution	ExecutionContext	Required	Read-only. See the type definition and usage context.
remainingCalls	number	Required	Read-only. Calls still available to this runner after the parent's reserve is applied.
callCount	number	Required	Read-only. Completed calls observed by this runner only.
totalCallCount	number	Required	Read-only. Includes descendant attempts; local callCount and journal remain isolated.

Member index

Member	Purpose
invoke	Invoke one model call. Named and shorthand input share the same lifecycle: validation, measurement, budget charge, streaming, commit. A caller-supplied signal only shortens the call lifetime. Invoke a prepared call whose settings cannot be replaced. Invoke with the default transport and a plain-text result. Invoke with a transport instance supplied at the call site. Invoke with a transport id registered on this runner. Invoke without narrowing the transport type.
prepare	Prepare a call and measure it before invocation. A prepared call is single-use and bound to the stage, output tokens and transport it was measured with; invoke rejects any attempt to replace those settings. Prepare a call for a transport instance supplied at the call site. Prepare a call for a transport id, typed by the runner's registered transports. Prepare a call without narrowing the transport type.

Member details

invoke

Invoke one model call.

Named and shorthand input share the same lifecycle: validation, measurement, budget charge, streaming, commit. A caller-supplied signal only shortens the call lifetime. Invoke a prepared call whose settings cannot be replaced. Invoke with the default transport and a plain-text result. Invoke with a transport instance supplied at the call site. Invoke with a transport id registered on this runner. Invoke without narrowing the transport type.

AgentModelRuntime.invoke(request: string): Promise<ModelResult<string>>

Invoke one model call.

Named and shorthand input share the same lifecycle: validation, measurement, budget charge, streaming, commit. A caller-supplied signal only shortens the call lifetime.

Parameter	Type	Passing	Description
request	string	Required	—

Returns: Promise<ModelResult<string>>.

Awaited value: ModelResult<string>.

Return value structure

Field	Type	Required	Description
value	string	Required	Read-only. See the type definition and usage context.
invocation	Readonly<ModelCallRecord>	Required	Read-only. See the type definition and usage context.

AgentModelRuntime.invoke<Result>(request: ModelCallRequest<never> & { readonly prepared: PreparedModelCall<Result>; }): Promise<ModelResult<Result>>

Invoke a prepared call whose settings cannot be replaced.

Type parameter	Constraint	Default type
Result	—	—

Parameter	Type	Passing	Description
request	ModelCallRequest<never> & { readonly prepared: PreparedModelCall<Result>; }	Required	—

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

Branch 1

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> & PreparedModelCall<Result>	Required	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	undefined	Optional	Read-only. See the type definition and usage context.
input	string	Required	See the type definition and usage context.
instructions	string | undefined	Optional	See the type definition and usage context.

Branch 2

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> & PreparedModelCall<Result>	Required	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	undefined	Optional	Read-only. See the type definition and usage context.
input	readonly ModelMessage[] | BuiltContext | ContextPlan	Required	See the type definition and usage context.
instructions	undefined	Optional	See the type definition and usage context.

Returns: Promise<ModelResult<Result>>.

Awaited value: ModelResult<Result>.

Return value structure

Field	Type	Required	Description
value	Result	Required	Read-only. See the type definition and usage context.
invocation	Readonly<ModelCallRecord>	Required	Read-only. See the type definition and usage context.

AgentModelRuntime.invoke(request: ModelCallRequest<never>): Promise<ModelResult<string>>

Invoke with the default transport and a plain-text result.

Parameter	Type	Passing	Description
request	ModelCallRequest<never>	Required	—

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

Branch 1

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	undefined	Optional	Read-only. See the type definition and usage context.
input	string	Required	See the type definition and usage context.
instructions	string | undefined	Optional	See the type definition and usage context.

Branch 2

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	undefined	Optional	Read-only. See the type definition and usage context.
input	readonly ModelMessage[] | BuiltContext | ContextPlan	Required	See the type definition and usage context.
instructions	undefined	Optional	See the type definition and usage context.

Returns: Promise<ModelResult<string>>.

Awaited value: ModelResult<string>.

Return value structure

Field	Type	Required	Description
value	string	Required	Read-only. See the type definition and usage context.
invocation	Readonly<ModelCallRecord>	Required	Read-only. See the type definition and usage context.

AgentModelRuntime.invoke<Result>(request: ModelCallRequest<ModelTransportDefinition<Result>> & { transport: ModelTransportDefinition<Result>; }): Promise<ModelResult<Result>>

Invoke with a transport instance supplied at the call site.

Type parameter	Constraint	Default type
Result	—	—

Parameter	Type	Passing	Description
request	ModelCallRequest<ModelTransportDefinition<Result>> & { transport: ModelTransportDefinition<Result>; }	Required	—

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

Branch 1

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	ModelTransportDefinition<Result>	Required	Read-only. See the type definition and usage context.
input	string	Required	See the type definition and usage context.
instructions	string | undefined	Optional	See the type definition and usage context.

Branch 2

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	ModelTransportDefinition<Result>	Required	Read-only. See the type definition and usage context.
input	readonly ModelMessage[] | BuiltContext | ContextPlan	Required	See the type definition and usage context.
instructions	undefined	Optional	See the type definition and usage context.

Returns: Promise<ModelResult<Result>>.

Awaited value: ModelResult<Result>.

Return value structure

Field	Type	Required	Description
value	Result	Required	Read-only. See the type definition and usage context.
invocation	Readonly<ModelCallRecord>	Required	Read-only. See the type definition and usage context.

AgentModelRuntime.invoke<const Id extends string>(request: ModelCallRequest<Id> & { readonly transport: Id; }): Promise<ModelResult<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>>

Invoke with a transport id registered on this runner.

Type parameter	Constraint	Default type
Id	string	—

Parameter	Type	Passing	Description
request	ModelCallRequest<Id> & { readonly transport: Id; }	Required	—

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

Branch 1

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	Id	Required	Read-only. See the type definition and usage context.
input	string	Required	See the type definition and usage context.
instructions	string | undefined	Optional	See the type definition and usage context.

Branch 2

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	Id	Required	Read-only. See the type definition and usage context.
input	readonly ModelMessage[] | BuiltContext | ContextPlan	Required	See the type definition and usage context.
instructions	undefined	Optional	See the type definition and usage context.

Returns: Promise<ModelResult<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>>.

Awaited value: ModelResult<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>.

Return value structure

Field	Type	Required	Description
value	RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>	Required	Read-only. See the type definition and usage context.
invocation	Readonly<ModelCallRecord>	Required	Read-only. See the type definition and usage context.

AgentModelRuntime.invoke(request: ModelCallRequest<string | ModelTransportDefinition<unknown>>): Promise<ModelResult<unknown>>

Invoke without narrowing the transport type.

Parameter	Type	Passing	Description
request	ModelCallRequest<string | ModelTransportDefinition<unknown>>	Required	—

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

Branch 1

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	string | ModelTransportDefinition<unknown> | undefined	Optional	Read-only. See the type definition and usage context.
input	string	Required	See the type definition and usage context.
instructions	string | undefined	Optional	See the type definition and usage context.

Branch 2

Field	Type	Required	Description
logger	SubFlowLogger | undefined	Optional	Read-only. Record this call in the supplied logger; omission adds no sub-flow record.
signal	AbortSignal | undefined	Optional	Read-only. Additional cancellation can shorten, never replace, the Runner lifetime.
diagnostics	DiagnosticContext | undefined	Optional	Read-only. Parent observation scope for this invocation; never changes execution budget or signal.
prepared	PreparedModelCall<unknown> | undefined	Optional	Read-only. Reuse a prepared call; its stage, transport and output reservation then take precedence.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	string | ModelTransportDefinition<unknown> | undefined	Optional	Read-only. See the type definition and usage context.
input	readonly ModelMessage[] | BuiltContext | ContextPlan	Required	See the type definition and usage context.
instructions	undefined	Optional	See the type definition and usage context.

Returns: Promise<ModelResult<unknown>>.

Awaited value: ModelResult<unknown>.

Return value structure

Field	Type	Required	Description
value	unknown	Required	Read-only. See the type definition and usage context.
invocation	Readonly<ModelCallRecord>	Required	Read-only. See the type definition and usage context.

prepare

Prepare a call and measure it before invocation.

A prepared call is single-use and bound to the stage, output tokens and transport it was measured with; invoke rejects any attempt to replace those settings. Prepare a call for a transport instance supplied at the call site. Prepare a call for a transport id, typed by the runner's registered transports. Prepare a call without narrowing the transport type.

AgentModelRuntime.prepare(request?: import("../structs/model/runtime.js").ModelPrepareRequest<never>): import("../structs/model/runtime.js").PreparedModelCall<string>

Prepare a call and measure it before invocation.

A prepared call is single-use and bound to the stage, output tokens and transport it was measured with; invoke rejects any attempt to replace those settings.

Parameter	Type	Passing	Description
request	ModelPrepareRequest<never> | undefined	Optional	—

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

Branch 1

undefined

Branch 2

Field	Type	Required	Description
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	undefined	Optional	Read-only. See the type definition and usage context.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.

Returns: PreparedModelCall<string>.

Return value structure

Field	Type	Required	Description
modelId	string | undefined	Optional	Read-only. Model binding the call was prepared with.
stageId	string	Required	Read-only. See the type definition and usage context.
transportId	string	Required	Read-only. See the type definition and usage context.
maxOutputTokens	number	Required	Read-only. See the type definition and usage context.
remainingCalls	number	Required	Read-only. Calls still available; a live value, so later spends are visible.
measure	(input: string | readonly ModelMessage[] | BuiltContext) => ModelInputMeasurement	Required	Preflight measurement of one input shape. Never marks the call used and never charges the budget.
options	Pick<ModelOptions, "functions" | "json" | "toolChoice" | "parallelToolCalls" | "temperature">	Required	Read-only. See the type definition and usage context.
schemaChars	number	Required	Read-only. See the type definition and usage context.
instruction	string | undefined	Optional	Read-only. See the type definition and usage context.
createResponse	() => ModelResponseCollector<string>	Required	See the type definition and usage context.

AgentModelRuntime.prepare<Result>(request: ModelPrepareRequest<ModelTransportDefinition<Result>> & { readonly transport: ModelTransportDefinition<Result>; }): PreparedModelCall<Result>

Prepare a call for a transport instance supplied at the call site.

Type parameter	Constraint	Default type
Result	—	—

Parameter	Type	Passing	Description
request	ModelPrepareRequest<ModelTransportDefinition<Result>> & { readonly transport: ModelTransportDefinition<Result>; }	Required	—

Fields of request

Field	Type	Required	Description
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	ModelTransportDefinition<Result>	Required	Read-only. See the type definition and usage context.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.

Returns: PreparedModelCall<Result>.

Return value structure

Field	Type	Required	Description
modelId	string | undefined	Optional	Read-only. Model binding the call was prepared with.
stageId	string	Required	Read-only. See the type definition and usage context.
transportId	string	Required	Read-only. See the type definition and usage context.
maxOutputTokens	number	Required	Read-only. See the type definition and usage context.
remainingCalls	number	Required	Read-only. Calls still available; a live value, so later spends are visible.
measure	(input: string | readonly ModelMessage[] | BuiltContext) => ModelInputMeasurement	Required	Preflight measurement of one input shape. Never marks the call used and never charges the budget.
options	Pick<ModelOptions, "functions" | "json" | "toolChoice" | "parallelToolCalls" | "temperature">	Required	Read-only. See the type definition and usage context.
schemaChars	number	Required	Read-only. See the type definition and usage context.
instruction	string | undefined	Optional	Read-only. See the type definition and usage context.
createResponse	() => ModelResponseCollector<Result>	Required	See the type definition and usage context.

AgentModelRuntime.prepare<const Id extends string>(request: ModelPrepareRequest<Id> & { readonly transport: Id; }): PreparedModelCall<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>

Prepare a call for a transport id, typed by the runner's registered transports.

Type parameter	Constraint	Default type
Id	string	—

Parameter	Type	Passing	Description
request	ModelPrepareRequest<Id> & { readonly transport: Id; }	Required	—

Fields of request

Field	Type	Required	Description
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	Id	Required	Read-only. See the type definition and usage context.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.

Returns: PreparedModelCall<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>.

Return value structure

Field	Type	Required	Description
modelId	string | undefined	Optional	Read-only. Model binding the call was prepared with.
stageId	string	Required	Read-only. See the type definition and usage context.
transportId	string	Required	Read-only. See the type definition and usage context.
maxOutputTokens	number	Required	Read-only. See the type definition and usage context.
remainingCalls	number	Required	Read-only. Calls still available; a live value, so later spends are visible.
measure	(input: string | readonly ModelMessage[] | BuiltContext) => ModelInputMeasurement	Required	Preflight measurement of one input shape. Never marks the call used and never charges the budget.
options	Pick<ModelOptions, "functions" | "json" | "toolChoice" | "parallelToolCalls" | "temperature">	Required	Read-only. See the type definition and usage context.
schemaChars	number	Required	Read-only. See the type definition and usage context.
instruction	string | undefined	Optional	Read-only. See the type definition and usage context.
createResponse	() => ModelResponseCollector<RegisteredTransportOutput<readonly ModelTransportDefinition<unknown>[], Id>>	Required	See the type definition and usage context.

AgentModelRuntime.prepare(request: import("../structs/model/runtime.js").ModelPrepareRequest<string | ModelTransportDefinition>): import("../structs/model/runtime.js").PreparedModelCall

Prepare a call without narrowing the transport type.

Parameter	Type	Passing	Description
request	ModelPrepareRequest<string | ModelTransportDefinition<unknown>>	Required	—

Fields of request

Field	Type	Required	Description
stageId	string | undefined	Optional	Read-only. See the type definition and usage context.
transport	string | ModelTransportDefinition<unknown> | undefined	Optional	Read-only. See the type definition and usage context.
maxOutputTokens	number | undefined	Optional	Read-only. See the type definition and usage context.

Returns: PreparedModelCall<unknown>.

Return value structure

Field	Type	Required	Description
modelId	string | undefined	Optional	Read-only. Model binding the call was prepared with.
stageId	string	Required	Read-only. See the type definition and usage context.
transportId	string	Required	Read-only. See the type definition and usage context.
maxOutputTokens	number	Required	Read-only. See the type definition and usage context.
remainingCalls	number	Required	Read-only. Calls still available; a live value, so later spends are visible.
measure	(input: string | readonly ModelMessage[] | BuiltContext) => ModelInputMeasurement	Required	Preflight measurement of one input shape. Never marks the call used and never charges the budget.
options	Pick<ModelOptions, "functions" | "json" | "toolChoice" | "parallelToolCalls" | "temperature">	Required	Read-only. See the type definition and usage context.
schemaChars	number	Required	Read-only. See the type definition and usage context.
instruction	string | undefined	Optional	Read-only. See the type definition and usage context.
createResponse	() => ModelResponseCollector<unknown>	Required	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.
• Reusing a base Workflow and Agent branches: add preserves the old Workflow and produces a new combined Workflow; fork inherits existing bindings and the branch origin.
• Bind once, multiple models per run, and switching across runs: Provide stable model configuration at construction; requests select by configuration ID instead of injecting a Provider repeatedly.
• Real tool invocation and in-request runtime: Core registers and executes real tools and returns receipts carrying an invocation; business authorization is owned by the implementation registered by the App.

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
• Check order for tool input, execution, output, and late results

Related definitions

• ExecutionContext
• ModelCallRecord
• ModelCallRequest
• ModelPrepareRequest
• ModelResult
• ModelRunner
• ModelTransportDefinition
• PreparedModelCall
• RegisteredTransportOutput