ContextPolicy

SUPPORT · type · 类型合同

Declared context policy for one stage.

导入

TypeScript

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

JavaScript

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

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

定义

类型： ContextPolicy

类型表达式

type ContextPolicy = | { mode: 'validate' }
  /**
   * Reduce content when a trigger is exceeded.
   *
   * Character and token triggers/targets may be combined; `targetInputChars`/`targetInputTokens`
   * define the size the reduction must reach.
   */
  | {
      mode: 'reduce';
      triggerChars?: number;
      targetInputChars?: number;
      triggerTokens?: number;
      targetInputTokens?: number;
      selection?: ContextSelection;
      steps: readonly ContextReduction[];
    }
  /** Verify that only the listed fragments changed value, without reducing anything. */
  | { mode: 'audit'; mutableFragmentIds: readonly string[] };

联合分支结构

ContextPolicy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
mode	"validate"	必需	见类型定义及调用场景。

分支 2

字段	类型	必需	说明
mode	"reduce"	必需	见类型定义及调用场景。
triggerChars	number | undefined	可省略	见类型定义及调用场景。
targetInputChars	number | undefined	可省略	见类型定义及调用场景。
triggerTokens	number | undefined	可省略	见类型定义及调用场景。
targetInputTokens	number | undefined	可省略	见类型定义及调用场景。
selection	ContextSelection | undefined	可省略	见类型定义及调用场景。
steps	readonly ContextReduction[]	必需	见类型定义及调用场景。

分支 3

字段	类型	必需	说明
mode	"audit"	必需	见类型定义及调用场景。
mutableFragmentIds	readonly string[]	必需	见类型定义及调用场景。

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

• ContextReduction
• ContextSelection