selectContextSteps

SUPPORT · function · Runtime value

Choose steps that fit the remaining call budget.

Feasibility uses exact trim previews and declared call ceilings; the reply reserve and the selector's own allowance are subtracted before candidates are considered, so neither can be spent on reductions.

Import

TypeScript

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

JavaScript

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

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

Definition

Call

selectContextSteps(input: SelectionInput): Promise<SelectionResult>

Choose steps that fit the remaining call budget.

Feasibility uses exact trim previews and declared call ceilings; the reply reserve and the selector's own allowance are subtracted before candidates are considered, so neither can be spent on reductions.

Parameter	Type	Passing	Description
input	SelectionInput	Required	—

Fields of input

Field	Type	Required	Description
signal	AbortSignal	Required	Read-only. See the type definition and usage context.
diagnostics	DiagnosticContext | undefined	Optional	See the type definition and usage context.
selection	ContextSelection	Required	See the type definition and usage context.
selectors	readonly ContextSelector[]	Required	See the type definition and usage context.
stageId	string	Required	Read-only. See the type definition and usage context.
candidates	readonly ContextSelectionCandidate[]	Required	Reducible candidates, already filtered and measured.
fragments	readonly ContextFragment[]	Required	Only reducible fragments; never protected request or system fragments.
currentTokens	number | undefined	Optional	Current input tokens, when a token budget applies.
requiredReductionTokens	number | undefined	Optional	Tokens that must be removed to satisfy the token budget.
currentChars	number	Required	See the type definition and usage context.
requiredReductionChars	number	Required	Characters that must be removed to satisfy the character budget.
remainingCalls	number	Required	Calls the selector may still spend through callModel.
callModel	ContextModelCall	Required	See the type definition and usage context.

Returns: Promise<SelectionResult>.

Awaited value: SelectionResult.

Return value structure

Field	Type	Required	Description
stepIds	string[]	Required	See the type definition and usage context.
reason	string	Required	See the type definition and usage context.

Examples

• Selecting reduction steps: sequence, fixed, automatic, or model: One typed policy set expresses multiple scenarios while preserving exact parameters and App-defined selection.

Process in registered order

Beginner · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
Support.validateContextSelection({ mode: 'sequence' }, []);
console.log(Object.keys(Support.contextSelectionCatalog));

JavaScript

import { Support } from '@jangts/agent-core';
Support.validateContextSelection({ mode: 'sequence' }, []);
console.log(Object.keys(Support.contextSelectionCatalog));

Choose a policy per scenario with exact overrides

Configuration · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
const localOnly = { mode: 'fixed' as const, kind: 'trim' as const };
const preserveMore = { mode: 'auto' as const, maxTrimLossRatio: 0.1, reserveCalls: 2 };
Support.validateContextSelection(localOnly, []);
Support.validateContextSelection(preserveMore, []);
console.log(localOnly, preserveMore);

JavaScript

import { Support } from '@jangts/agent-core';
const localOnly = { mode: 'fixed', kind: 'trim' };
const preserveMore = { mode: 'auto', maxTrimLossRatio: 0.1, reserveCalls: 2 };
Support.validateContextSelection(localOnly, []);
Support.validateContextSelection(preserveMore, []);
console.log(localOnly, preserveMore);

Related policy source

• Selection policy catalog, reserved quota, and feasibility filtering