ContextAssemblyOptions

SUPPORT · interface · 类型合同

Assembly options for placement-based projections.

导入

TypeScript

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

JavaScript

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

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

定义

interface ContextAssemblyOptions<Input, Id, Placement>

继承或实现： ContextBuilderOptions<Input>。

泛型参数

类型参数	约束	默认类型
Input	—	—
Id	string	—
Placement	string	—

字段结构

字段	类型	必需	说明
fragment	(id: Id, value: ContextFragment["value"]) => ContextFragment	必需	只读。Builds a fragment for a single-fragment projection.
contributions	Readonly<Record<Placement, (input: Input) => readonly ContextFragment[]>> | undefined	可省略	只读。Contribution handlers keyed by placement; each expands to zero or more fragments.
maxInputChars	number | ((input: Input) => number) | undefined	可省略	只读。Character budget, constant or derived from the request; at least one of these is required.
transform	((fragment: ContextFragment, input: Input) => ContextFragment) | undefined	可省略	只读。Applied to every produced fragment before assembly; must be synchronous.

成员目录

成员	用途
fragment	Builds a fragment for a single-fragment projection.

成员详情

fragment

Builds a fragment for a single-fragment projection.

ContextAssemblyOptions.fragment(id: Id, value: ContextFragment["value"]): ContextFragment

参数	类型	传递	说明
id	Id	必需	—
value	string | Record<string, unknown>	必需	—

返回： ContextFragment。

返回值结构

字段	类型	必需	说明
id	string	必需	Unique, stable id matching ^[a-z][a-zA-Z0-9:._-]*$; duplicates are rejected.
sourceId	string	必需	Owning source (module or registration) used to explain where the content came from.
trust	ContextTrust	必需	Producer trust level. user and tool content cannot become a system message.
lifetime	ContextLifetime	必需	Declared validity window of this content.
maxChars	number	必需	Hard upper bound in JSON characters; must be a positive safe integer.
role	"system" | "user"	必需	Message slot the fragment occupies when assembled.
value	string | Record<string, unknown>	必需	Rendered content. A system message accepts a string only, never a record.

使用示例

• 上下文装配：稳定元数据配置一次：Support 提前绑定片段元数据、格式化和顺序，请求只提供变化的业务输入。

一次配置，以后只给问题和历史

入门 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
type Input = { question: string; history: readonly { role: string; content: string }[] };
const builder = Support.defineContextFragments<Input>([
  { id: 'question', sourceId: 'request', trust: 'user', lifetime: 'turn', maxChars: 1000,
    role: 'user', format: input => input.question },
  { id: 'history', sourceId: 'conversation', trust: 'user', lifetime: 'turn', maxChars: 10000,
    role: 'user', format: input => ({ messages: input.history }) },
], { maxInputChars: 1200 });
const context = builder.build({ input: { question: '服务状态？', history: [] } });
console.log(context.messages);

JavaScript

import { Support } from '@jangts/agent-core';
const builder = Support.defineContextFragments([
    { id: 'question', sourceId: 'request', trust: 'user', lifetime: 'turn', maxChars: 1000,
        role: 'user', format: input => input.question },
    { id: 'history', sourceId: 'conversation', trust: 'user', lifetime: 'turn', maxChars: 10000,
        role: 'user', format: input => ({ messages: input.history }) },
], { maxInputChars: 1200 });
const context = builder.build({ input: { question: '服务状态？', history: [] } });
console.log(context.messages);

同一个 builder 提前给出计划

配置 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
type Input = { question: string; history: readonly { role: string; content: string }[] };
const builder = Support.defineContextFragments<Input>([
  { id: 'question', sourceId: 'request', trust: 'user', lifetime: 'turn', maxChars: 1000,
    role: 'user', format: input => input.question },
  { id: 'history', sourceId: 'conversation', trust: 'user', lifetime: 'turn', maxChars: 10000,
    role: 'user', format: input => ({ messages: input.history }) },
], { maxInputChars: 1200 });
const input = { question: '服务状态？', history: [] };
const plan = builder.plan({ input });
const expanded = builder.fragments(input);
console.log(plan.maxInputChars, expanded.map(fragment => fragment.id));
const largerRequest = builder.build({ input, maxInputChars: 2000 });
console.log(largerRequest.maxInputChars);

JavaScript

import { Support } from '@jangts/agent-core';
const builder = Support.defineContextFragments([
    { id: 'question', sourceId: 'request', trust: 'user', lifetime: 'turn', maxChars: 1000,
        role: 'user', format: input => input.question },
    { id: 'history', sourceId: 'conversation', trust: 'user', lifetime: 'turn', maxChars: 10000,
        role: 'user', format: input => ({ messages: input.history }) },
], { maxInputChars: 1200 });
const input = { question: '服务状态？', history: [] };
const plan = builder.plan({ input });
const expanded = builder.fragments(input);
console.log(plan.maxInputChars, expanded.map(fragment => fragment.id));
const largerRequest = builder.build({ input, maxInputChars: 2000 });
console.log(largerRequest.maxInputChars);

相关策略源码

• 装配顺序、依赖快照与请求预算覆盖

相关定义

• ContextBuilderOptions
• ContextFragment