ContextReduction

SUPPORT · type · 类型合同

One declared reduction step.

导入

TypeScript

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

JavaScript

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

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

定义

类型： ContextReduction

类型表达式

type ContextReduction = | {
      id: string;
      kind: 'trim';
      fragmentId: string;
      field: string;
      targetChars: number;
      grouping: ContextHistoryGrouping;
      keepGroups: number;
    }
  /** Rewrites one fragment through a registered compressor down to `targetChars`. */
  | ({
      id: string;
      kind: 'compress';
      fragmentId: string;
      targetChars: number;
      /** Recent history the compressor must preserve verbatim. */
      preserve?: ContextRecentHistory;
    } & ContextHandlerReference);

联合分支结构

ContextReduction的可选结构： 选择其中一种结构，各分支的字段要求分别列出。

分支 1

字段	类型	必需	说明
id	string	必需	见类型定义及调用场景。
kind	"trim"	必需	见类型定义及调用场景。
fragmentId	string	必需	见类型定义及调用场景。
field	string	必需	见类型定义及调用场景。
targetChars	number	必需	见类型定义及调用场景。
grouping	ContextHistoryGrouping	必需	见类型定义及调用场景。
keepGroups	number	必需	见类型定义及调用场景。

分支 2

字段	类型	必需	说明
id	string	必需	见类型定义及调用场景。
kind	"compress"	必需	见类型定义及调用场景。
fragmentId	string	必需	见类型定义及调用场景。
targetChars	number	必需	见类型定义及调用场景。
preserve	ContextRecentHistory | undefined	可省略	Recent history the compressor must preserve verbatim.
handlerId	string	必需	只读。Registered handler id; an unknown id is rejected before execution.

使用示例

• 上下文策略：验证、缩减与审计：Support 给出可替换的策略实现，Core 保留最终输入合同和预算检查。

显式使用只校验策略

入门 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
import type { ContextPolicy } from '@jangts/agent-core/support/context';
const policy: ContextPolicy = { mode: 'validate' };
Support.validateContextPolicy(policy, [], []);
console.log(policy.mode);

JavaScript

import { Support } from '@jangts/agent-core';
const policy = { mode: 'validate' };
Support.validateContextPolicy(policy, [], []);
console.log(policy.mode);

从真实业务片段配置缩减顺序

配置 · Node.js

这些数字是示例业务的显式选择，不是 SDK 推荐适用于所有模型的容量。

TypeScript

import { Support } from '@jangts/agent-core';
import type { ContextPolicy } from '@jangts/agent-core/support/context';
const policy: ContextPolicy = { mode: 'reduce', triggerChars: 1800, targetInputChars: 1500,
  selection: { mode: 'sequence' },
  steps: [{ id: 'recent-history', kind: 'trim', fragmentId: 'history', field: 'messages',
    grouping: { kind: 'user-turn' }, keepGroups: 2, targetChars: 1000 }],
};
Support.validateContextPolicy(policy, [], []);
console.log(policy.steps);

JavaScript

import { Support } from '@jangts/agent-core';
const policy = { mode: 'reduce', triggerChars: 1800, targetInputChars: 1500,
    selection: { mode: 'sequence' },
    steps: [{ id: 'recent-history', kind: 'trim', fragmentId: 'history', field: 'messages',
            grouping: { kind: 'user-turn' }, keepGroups: 2, targetChars: 1000 }],
};
Support.validateContextPolicy(policy, [], []);
console.log(policy.steps);

相关策略源码

• 策略与缩减操作的真实调度目录

相关定义

• ContextHandlerReference
• ContextHistoryGrouping
• ContextRecentHistory