ContextSelector

SUPPORT · interface · 类型合同

Model or local selector that chooses which reductions to apply.

导入

TypeScript

import type { ContextSelector } from '@jangts/agent-core/support';

JavaScript

/** @typedef {import('@jangts/agent-core/support').ContextSelector} ContextSelector */

其他公开入口：@jangts/agent-core/support、@jangts/agent-core/support/context。

定义

interface ContextSelector

字段结构

字段	类型	必需	说明
id	string	必需	见类型定义及调用场景。
maxCalls	number | undefined	可省略	Maximum model calls made through callModel, default 1; 0 permits a local selector.
select	(call: ContextSelectionCall, context: ExecutionContext) => Promise<readonly string[]>	必需	Returns selected reduction ids; unknown ids are rejected.

成员目录

成员	用途
select	Returns selected reduction ids; unknown ids are rejected.

成员详情

select

Returns selected reduction ids; unknown ids are rejected.

ContextSelector.select(call: ContextSelectionCall, context: ExecutionContext): Promise<readonly string[]>

Returns selected reduction ids; unknown ids are rejected.

参数	类型	传递	说明
call	ContextSelectionCall	必需	—
context	ExecutionContext	必需	—

call 的字段

字段	类型	必需	说明
stageId	string	必需	只读。见类型定义及调用场景。
candidates	readonly ContextSelectionCandidate[]	必需	Reducible candidates, already filtered and measured.
fragments	readonly ContextFragment[]	必需	Only reducible fragments; never protected request or system fragments.
currentTokens	number | undefined	可省略	Current input tokens, when a token budget applies.
requiredReductionTokens	number | undefined	可省略	Tokens that must be removed to satisfy the token budget.
currentChars	number	必需	见类型定义及调用场景。
requiredReductionChars	number	必需	Characters that must be removed to satisfy the character budget.
remainingCalls	number	必需	Calls the selector may still spend through callModel.
callModel	ContextModelCall	必需	见类型定义及调用场景。

context 的字段

字段	类型	必需	说明
logger	SubFlowLog | undefined	可省略	只读。Explicit optional recorder for this operation; never inferred from diagnostics.
signal	AbortSignal	必需	只读。Non-optional cancellation signal; never undefined once execution has started.
diagnostics	DiagnosticContext | undefined	可省略	只读。Diagnostic scope of the enclosing call, when recording is enabled.

返回： Promise<readonly string[]>。

等待后的值： readonly string[]。

使用示例

• 压缩器与选择器：推荐实现和自定义算法：将提示词、输出解析和算法绑定为 handler；模型 I/O 通过同一请求的 callModel。

绑定一个文本压缩 handler

入门 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
const compressor = Support.createContextCompressor({
  id: 'history-summary', instruction: '保留事实、时间和未完成事项，精简重复表达。',
  transport: 'core:plain-text', maxOutputTokens: 500,
  parse(value: unknown) { if (typeof value !== 'string' || !value.trim()) throw new TypeError('需要非空摘要'); return value; },
});
console.log(compressor.id);

JavaScript

import { Support } from '@jangts/agent-core';
const compressor = Support.createContextCompressor({
    id: 'history-summary', instruction: '保留事实、时间和未完成事项，精简重复表达。',
    transport: 'core:plain-text', maxOutputTokens: 500,
    parse(value) { if (typeof value !== 'string' || !value.trim())
        throw new TypeError('需要非空摘要'); return value; },
});
console.log(compressor.id);

选择器明确控制可见摘录范围

配置 · Node.js

selector-json 必须由 App 注册，返回 value={stepIds:string[]}；不能把普通文本传输当成已解析 JSON。此例只展示 handler 装配，不发请求。

TypeScript

import { Support } from '@jangts/agent-core';
const selector = Support.createContextSelector({ id: 'select-reduction',
  transport: 'selector-json', maxOutputTokens: 200, maxExcerptChars: 1000,
});
console.log(selector.id);

JavaScript

import { Support } from '@jangts/agent-core';
const selector = Support.createContextSelector({ id: 'select-reduction',
    transport: 'selector-json', maxOutputTokens: 200, maxExcerptChars: 1000,
});
console.log(selector.id);

相关策略源码

• 默认选择指令与摘录范围
• 压缩请求与真实 callModel 合同

相关定义

• ContextSelectionCall
• ExecutionContext