ContextStrategyOptions

SUPPORT · type · Type contract

One history declaration that generates a step, or an explicit step list with optional history fields (fragment, field, preset, targetChars, keepGroups, grouping).

Import

TypeScript

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

JavaScript

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

Other public entry points:@jangts/agent-core/support, @jangts/agent-core/support/context.

Definition

Type: ContextStrategyOptions

Type expression

type ContextStrategyOptions = | GeneratedContextStrategyOptions
  | (ContextStrategySettings &
      Partial<HistoryStrategy> & {
        readonly steps: readonly ContextReduction[];
        readonly kind?: 'recent' | 'continuity';
        readonly compressor?: ContextCompressor;
      });

Union branch structure

Optional shapes of ContextStrategyOptions: choose one shape; required fields for each branch are listed separately.

Branch 1

Field	Type	Required	Description
fragment	Pick<ContextFragment, "id" | "maxChars">	Required	Read-only. Reuse the registered fragment identity and its existing hard size allowance.
field	string	Required	Read-only. See the type definition and usage context.
preset	"compact" | "balanced" | "extended" | undefined	Optional	Read-only. See the type definition and usage context.
targetChars	number | undefined	Optional	Read-only. See the type definition and usage context.
keepGroups	number | undefined	Optional	Read-only. See the type definition and usage context.
grouping	ContextHistoryGrouping | undefined	Optional	Read-only. See the type definition and usage context.
selection	ContextSelection | undefined	Optional	See the type definition and usage context.
triggerChars	number | undefined	Optional	See the type definition and usage context.
targetInputChars	number | undefined	Optional	See the type definition and usage context.
targetInputTokens	number | undefined	Optional	See the type definition and usage context.
triggerTokens	number | undefined	Optional	See the type definition and usage context.
steps	readonly ContextReduction[] | undefined	Optional	Read-only. See the type definition and usage context.
compressors	readonly ContextCompressor[] | undefined	Optional	Read-only. See the type definition and usage context.
selectors	readonly ContextSelector[] | undefined	Optional	Read-only. See the type definition and usage context.
kind	"recent"	Required	Read-only. See the type definition and usage context.
compressor	undefined	Optional	Read-only. See the type definition and usage context.

Branch 2

Field	Type	Required	Description
fragment	Pick<ContextFragment, "id" | "maxChars">	Required	Read-only. Reuse the registered fragment identity and its existing hard size allowance.
field	string	Required	Read-only. See the type definition and usage context.
preset	"compact" | "balanced" | "extended" | undefined	Optional	Read-only. See the type definition and usage context.
targetChars	number | undefined	Optional	Read-only. See the type definition and usage context.
keepGroups	number | undefined	Optional	Read-only. See the type definition and usage context.
grouping	ContextHistoryGrouping | undefined	Optional	Read-only. See the type definition and usage context.
selection	ContextSelection | undefined	Optional	See the type definition and usage context.
triggerChars	number | undefined	Optional	See the type definition and usage context.
targetInputChars	number | undefined	Optional	See the type definition and usage context.
targetInputTokens	number | undefined	Optional	See the type definition and usage context.
triggerTokens	number | undefined	Optional	See the type definition and usage context.
steps	readonly ContextReduction[] | undefined	Optional	Read-only. See the type definition and usage context.
compressors	readonly ContextCompressor[] | undefined	Optional	Read-only. See the type definition and usage context.
selectors	readonly ContextSelector[] | undefined	Optional	Read-only. See the type definition and usage context.
kind	"continuity"	Required	Read-only. See the type definition and usage context.
compressor	ContextCompressor	Required	Read-only. See the type definition and usage context.

Branch 3

Field	Type	Required	Description
selection	ContextSelection | undefined	Optional	See the type definition and usage context.
triggerChars	number | undefined	Optional	See the type definition and usage context.
targetInputChars	number | undefined	Optional	See the type definition and usage context.
targetInputTokens	number | undefined	Optional	See the type definition and usage context.
triggerTokens	number | undefined	Optional	See the type definition and usage context.
steps	readonly ContextReduction[]	Required	Read-only. See the type definition and usage context.
compressors	readonly ContextCompressor[] | undefined	Optional	Read-only. See the type definition and usage context.
selectors	readonly ContextSelector[] | undefined	Optional	Read-only. See the type definition and usage context.
fragment	Pick<ContextFragment, "id" | "maxChars"> | undefined	Optional	Read-only. Reuse the registered fragment identity and its existing hard size allowance.
field	string | undefined	Optional	Read-only. See the type definition and usage context.
preset	"compact" | "balanced" | "extended" | undefined	Optional	Read-only. See the type definition and usage context.
targetChars	number | undefined	Optional	Read-only. See the type definition and usage context.
keepGroups	number | undefined	Optional	Read-only. See the type definition and usage context.
grouping	ContextHistoryGrouping | undefined	Optional	Read-only. See the type definition and usage context.
kind	"recent" | "continuity" | undefined	Optional	Read-only. See the type definition and usage context.
compressor	ContextCompressor | undefined	Optional	Read-only. See the type definition and usage context.

Examples

• Generate processing strategies from history semantics: Reuse fragment identity and hard budgets to generate complete steps and references for recent or continuity.

Reuse an existing fragment to generate a recent-history strategy

Beginner · 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);

Add kept groups and target size to the same configuration

Configuration · 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);

Related policy source

• Scenario catalog, generated steps, and precise overrides

Related definitions

• ContextCompressor
• ContextFragment
• ContextHandlerReference
• ContextReduction
• ContextSelector
• ContextStrategySettings