contextHistoryStrategies

SUPPORT · constant · 运行时值

导入

TypeScript

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

JavaScript

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

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

定义

const contextHistoryStrategies: Readonly<{ compact: Readonly<{ targetRatio: 0.25; keepGroups: 1; }>; balanced: Readonly<{ targetRatio: 0.5; keepGroups: 3; }>; extended: Readonly<{ targetRatio: 0.75; keepGroups: 6; }>; }>

字段结构

字段	类型	必需	说明
compact	Readonly<{ targetRatio: 0.25; keepGroups: 1; }>	必需	见类型定义及调用场景。
balanced	Readonly<{ targetRatio: 0.5; keepGroups: 3; }>	必需	见类型定义及调用场景。
extended	Readonly<{ targetRatio: 0.75; keepGroups: 6; }>	必需	见类型定义及调用场景。

使用示例

• 从历史语义生成处理策略：复用片段身份与硬预算，生成 recent 或 continuity 的完整步骤和引用。

复用已有片段生成最近历史策略

入门 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
const fragment = { id: 'history', maxChars: 4000 };
const strategy = Support.createContextStrategy({ kind: 'recent', fragment, field: 'messages' });
console.log(strategy.policy, strategy.compressors);

JavaScript

import { Support } from '@jangts/agent-core';
const fragment = { id: 'history', maxChars: 4000 };
const strategy = Support.createContextStrategy({ kind: 'recent', fragment, field: 'messages' });
console.log(strategy.policy, strategy.compressors);

同一配置增加保留组数与目标大小

配置 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
const fragment = { id: 'history', maxChars: 4000 };
const strategy = Support.createContextStrategy({ kind: 'recent', fragment, field: 'messages',
  keepGroups: 3, targetChars: 2500, grouping: { kind: 'user-turn' },
});
console.log(strategy.policy);

JavaScript

import { Support } from '@jangts/agent-core';
const fragment = { id: 'history', maxChars: 4000 };
const strategy = Support.createContextStrategy({ kind: 'recent', fragment, field: 'messages',
    keepGroups: 3, targetChars: 2500, grouping: { kind: 'user-turn' },
});
console.log(strategy.policy);

需要承接旧话题时明确提供压缩算法

扩展 · Node.js

本例只装配策略。将 policy/compressors/selectors 作为原上下文节点配置，不在这里发新请求或创建额外额度。

TypeScript

import { Support } from '@jangts/agent-core';
const compressor = Support.createContextCompressor({ id: 'history-summary',
  instruction: '按资料原意概括旧历史，保留事实、时间和未完成事项。',
  transport: 'core:plain-text', maxOutputTokens: 500,
  parse(value: unknown) { if (typeof value !== 'string' || !value.trim()) throw new TypeError('需要摘要'); return { messages: [{ role: 'user', content: value }] }; },
});
const strategy = Support.createContextStrategy({ kind: 'continuity',
  fragment: { id: 'history', maxChars: 4000 }, field: 'messages', compressor,
  targetChars: 2500, keepGroups: 2,
});
console.log(strategy.policy, strategy.compressors.map(item => item.id));

JavaScript

import { Support } from '@jangts/agent-core';
const compressor = Support.createContextCompressor({ id: 'history-summary',
    instruction: '按资料原意概括旧历史，保留事实、时间和未完成事项。',
    transport: 'core:plain-text', maxOutputTokens: 500,
    parse(value) { if (typeof value !== 'string' || !value.trim())
        throw new TypeError('需要摘要'); return { messages: [{ role: 'user', content: value }] }; },
});
const strategy = Support.createContextStrategy({ kind: 'continuity',
    fragment: { id: 'history', maxChars: 4000 }, field: 'messages', compressor,
    targetChars: 2500, keepGroups: 2,
});
console.log(strategy.policy, strategy.compressors.map(item => item.id));

相关策略源码

• 场景目录、生成的步骤和精确覆盖