@tokenlens/helpers

@tokenlens/helpers

Utility helpers focused on context caps and rough cost estimation. DI‑first: pass providers from fetchModels() (or getModels() for a static set).

Install

• npm: npm i @tokenlens/helpers
• pnpm: pnpm add @tokenlens/helpers
• yarn: yarn add @tokenlens/helpers

Focused Exports

• Context: getContext({ modelId, providers })
• Cost: getTokenCosts({ modelId, usage, providers })
• Combined: getUsage({ modelId, usage, providers, reserveOutput? })
• Types: ContextData, TokenCosts, UsageData

Deprecated (use focused exports instead)

• Context: getContextWindow, remainingContext, percentRemaining, fitsContext
• Usage: normalizeUsage, breakdownTokens, consumedTokens
• Cost: estimateCost
• Compaction: shouldCompact, contextHealth, tokensToCompact
• Conversation: sumUsage, estimateConversationCost, computeContextRot, nextTurnBudget
• DI: sourceFromModels, sourceFromCatalog, selectStaticModels

Usage

import { fetchModels } from 'tokenlens';
import { getContext, getTokenCosts, getUsage } from '@tokenlens/helpers';

const openai = await fetchModels('openai');
const modelId = 'openai/gpt-4o-mini';
const usage = { prompt_tokens: 1000, completion_tokens: 500 };

const { maxInput, maxOutput, maxTotal } = getContext(modelId, openai);
const {
  inputUSD,
  outputUSD,
  reasoningUSD,
  cacheReadUSD,
  cacheWriteUSD,
  totalUSD,
} = getTokenCosts(modelId, usage, openai);
const summary = getUsage(modelId, usage, openai);

Notes

• IDs can be provider/model, provider:id, or providerless model.
• Version dots normalize to dashes in the model segment.
• Cost outputs are estimates based on models.dev pricing fields. For authoritative cost numbers, read pricing and usage metrics from your model provider's API responses at runtime.

Back‑compat via tokenlens

import { getContext, getTokenCosts, getUsage } from 'tokenlens';
// These wrappers inject a default providers set if not supplied.

License MIT