ContextTokenMeasurement

SUPPORT · interface · Type contract

Injected token measurement for token-triggered policies.

Import

TypeScript

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

JavaScript

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

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

Definition

interface ContextTokenMeasurement

Field structure

Field	Type	Required	Description
counterId	string	Required	Tokenizer identity, reported in the processing report.
inputLimit	number	Required	Input token ceiling the measurement is compared against.
measure	(messages: readonly ModelMessage[]) => number	Required	See the type definition and usage context.

Member index

Member	Purpose
measure	See the overload below for full inputs and outputs.

Member details

measure

ContextTokenMeasurement.measure(messages: readonly ModelMessage[]): number

Parameter	Type	Passing	Description
messages	readonly ModelMessage[]	Required	—

Returns: number.

Examples

• Context policy: validate, reduce, and audit: Support provides replaceable policy implementations while Core keeps the final input contract and budget checks.

Explicitly use a validation-only policy

Beginner · 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);

Configure reduction order from real business fragments

Configuration · Node.js

These numbers are explicit choices for the example business, not SDK recommendations for capacities that suit all models.

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);

Related policy source

• Real scheduling catalog for policies and reduction operations

Related definitions

• ModelMessage