1manfactory / ai-costs
Unofficial PHP library for calculating LLM API costs from usage payloads.
Requires
- php: ^8.2
Requires (Dev)
- phpmd/phpmd: ^2.15
- phpstan/phpstan: ^2.1
- phpunit/phpunit: ^11.5
- squizlabs/php_codesniffer: ^4.0
README
ai-costs is an unofficial PHP library for calculating LLM API costs from usage payloads.
It is designed to stay SDK-agnostic: feed it an OpenAI, Anthropic Claude, or Google Gemini usage payload, or a normalized usage object, and it returns a detailed cost breakdown.
Warning
This library provides estimates only. I do not guarantee the accuracy, completeness, or fitness of the calculated values for any billing purpose. The amounts actually billed by the provider are authoritative and always take precedence.
Units
All calculated cost values are returned as integers in usd_microcent.
usd_microcentis the only money unit used by this package1 USD = 100_000 usd_microcent1 usd_microcent = 0.00001 USD = 0.001 cents1 cent = 1_000 usd_microcent- Provider APIs do not return money amounts; they return usage counts, and this package converts those counts into estimated
usd_microcent - Public variable and method names use explicit unit suffixes like
InUsdMicrocent - The package returns integers only
Current scope
- OpenAI
Responses APIusage extraction - OpenAI
Chat Completions APIusage extraction - Anthropic
Messages APIusage extraction - Google Gemini
generateContentusage extraction - Text token pricing for selected GPT-5.6, GPT-5.5, GPT-5.4, Claude, and Gemini 2.5 models
- GPT-5.6 Sol, Terra, and Luna across
standard,batch,flex, and selectedpriority - Generic OpenAI cache-write token pricing and Anthropic 5-minute and 1-hour cache writes
- Automatic long-context pricing where a documented threshold exists
- Explicit short- or long-context selection through
ContextPricingMode - Time-dependent static price cards such as Claude Sonnet 5 introductory and regular pricing
- Helper charges for web search, file search, fixed 20-minute container sessions, and eligible minute-billed container sessions
Installation
composer require 1manfactory/ai-costs
Quick start
<?php declare(strict_types=1); use AiCosts\CostCalculator; use AiCosts\Enum\BillingMode; use AiCosts\OpenAI\OpenAIResponsesUsageExtractor; use AiCosts\OpenAI\OpenAIToolPricing; use AiCosts\Pricing\StaticPriceProvider; use AiCosts\Value\BillingContext; $payload = [ 'model' => 'gpt-5.4', 'usage' => [ 'input_tokens' => 1200, 'input_tokens_details' => ['cached_tokens' => 200], 'output_tokens' => 300, 'output_tokens_details' => ['reasoning_tokens' => 50], ], ]; $extractor = new OpenAIResponsesUsageExtractor(); $usage = $extractor->extract($payload); $calculator = new CostCalculator(StaticPriceProvider::default()); $breakdown = $calculator->calculate( $usage, new BillingContext( billingMode: BillingMode::STANDARD, additionalCharges: [ OpenAIToolPricing::webSearchCalls(3), ], ), ); echo $breakdown->inputCostInUsdMicrocent; echo $breakdown->cachedInputCostInUsdMicrocent; echo $breakdown->outputCostInUsdMicrocent; echo $breakdown->additionalChargesInUsdMicrocent; echo $breakdown->totalCostInUsdMicrocent;
Included building blocks
AiCosts\CostCalculatorAiCosts\Pricing\StaticPriceProviderAiCosts\OpenAI\OpenAIResponsesUsageExtractorAiCosts\OpenAI\OpenAIChatCompletionsUsageExtractorAiCosts\Anthropic\AnthropicMessagesUsageExtractorAiCosts\Gemini\GeminiGenerateContentUsageExtractorAiCosts\OpenAI\OpenAIToolPricing
Pricing catalog metadata
$catalog = StaticPriceProvider::default(); echo $catalog->version; echo $catalog->provider('openai')->verifiedAt; foreach ($catalog->provider('openai')->sourceUrls as $sourceUrl) { echo $sourceUrl . PHP_EOL; }
versionidentifies the revision of the bundled pricing catalog.verifiedAtis the last verification date recorded for that provider.sourceUrlslists the official documentation URLs used for that provider and the global catalog.- The metadata does not prove that prices remained unchanged after the recorded verification date.
More examples
GPT-5.6 with automatic long-context detection
use AiCosts\Value\UsageBreakdown; $usage = new UsageBreakdown( model: 'gpt-5.6', inputTokens: 300_000, cachedInputTokens: 20_000, outputTokens: 10_000, cacheWriteInputTokens: 30_000, );
GPT-5.5 Pro with explicit long context
use AiCosts\Enum\ContextPricingMode; new BillingContext( billingMode: BillingMode::STANDARD, contextPricingMode: ContextPricingMode::LONG, );
Long-context prices for gpt-5.5-pro are included in the catalog. Automatic switching stays disabled because the official model page does not document a threshold, so ContextPricingMode::LONG is the explicit opt-in.
Sonnet 5 with a fixed pricing date
use DateTimeImmutable; $provider = StaticPriceProvider::default( new DateTimeImmutable('2026-08-31'), ); $provider = StaticPriceProvider::default( new DateTimeImmutable('2026-09-01'), );
Minute-billed container sessions
OpenAIToolPricing::containerSessionMinutes( memoryGb: 4, durationMinutes: 13, );
Notes
- The packaged price catalog is intentionally static and versioned in the repo.
- Long-context thresholds are only auto-applied where the threshold is explicitly documented in OpenAI model docs.
gpt-5.5-prolong-context prices are included, but automatic switching remains disabled because no official threshold is documented.- Anthropic prompt caching reads plus 5-minute and 1-hour cache writes are supported when the API response includes the detailed
usage.cache_creationbreakdown. - OpenAI generic cache writes are supported when usage payloads report
cache_write_tokens. - Gemini support currently targets the stable
gemini-2.5-*text-output models included in the bundled catalog. - Explicit Gemini cache storage charges and grounding/tool surcharges are not auto-derived from a single response payload in this MVP.
- Audio token pricing is intentionally blocked in this MVP so the library does not undercount usage silently.
- All calculated values are estimates only; authoritative billing always comes from the respective provider.
- Claude and Gemini usage is estimated from official public pricing docs for the selected models bundled here; provider billing remains authoritative.
- Canonical cost outputs are integer
usd_microcent. - The package is not affiliated with or endorsed by OpenAI, Anthropic, or Google.
- This package is licensed under the MIT License.
Development
Run the local PHP checks manually with Composer:
composer lint:syntax composer lint:phpstan composer lint:phpmd composer lint:phpcs composer lint:all
The versioned Git hook lives in .githooks/pre-commit and this repository is configured to use it via git config core.hooksPath .githooks.
Every git commit runs composer lint:all; the commit is blocked immediately when one of the checks fails.
Release flow
This repository uses a GitHub Actions workflow at .github/workflows/release-tag.yml to create a new patch tag on every push to main.
- First release tag:
v0.1.0 - Later pushes on
main:v0.1.1,v0.1.2,v0.1.3, ...
That means the publishing path is:
local repository -> GitHub main -> automatic Git tag -> Packagist update
After the repository is submitted once on Packagist, each new Git tag becomes a new Composer-installable package version.
Pricing sources
The bundled pricing catalog is based on official provider docs as of 2026-07-15.
On 2026-07-15, the bundled model prices and helper charges were re-checked against the official pricing pages linked below. Gemini 2.5 catalog values remained unchanged in this verification pass; OpenAI and Claude entries were expanded to include GPT-5.6, explicit OpenAI cache writes, minute-billed eligible container sessions, Claude Fable 5, Claude Opus 4.8, and dated Claude Sonnet 5 pricing.
| Provider | Included model families | Billing modes in catalog | Last verified |
|---|---|---|---|
| OpenAI | gpt-5.6-sol, gpt-5.6-terra, gpt-5.6-luna, gpt-5.5, gpt-5.5-pro, gpt-5.4, gpt-5.4-mini, gpt-5.4-nano, gpt-5.4-pro, gpt-5, gpt-5-mini, gpt-5-nano, gpt-5-pro, gpt-4.1, gpt-4.1-mini, gpt-4.1-nano, gpt-4o, gpt-4o-mini, o1, o1-mini, o1-pro, o3, o3-mini, o3-pro, o4-mini, o3-deep-research, o4-mini-deep-research, codex-mini-latest, computer-use-preview, gpt-4-turbo, gpt-4, gpt-3.5-turbo, gpt-3.5-turbo-instruct |
standard, selected batch, selected flex, selected priority |
2026-07-15 |
| Anthropic | claude-fable-5, claude-opus-4-8, claude-opus-4-7, claude-sonnet-5, claude-sonnet-4-6, claude-haiku-4-5-20251001 plus alias claude-haiku-4-5 |
standard, batch |
2026-07-15 |
| Google Gemini | gemini-2.5-pro, gemini-2.5-flash, gemini-2.5-flash-lite |
standard, batch, flex, priority |
2026-07-15 |
- OpenAI pricing overview: https://developers.openai.com/api/docs/pricing
- OpenAI prompt caching: https://developers.openai.com/api/docs/guides/prompt-caching
- OpenAI GPT-5.6 Sol model page: https://developers.openai.com/api/docs/models/gpt-5.6-sol
- OpenAI GPT-5.6 Terra model page: https://developers.openai.com/api/docs/models/gpt-5.6-terra
- OpenAI GPT-5.6 Luna model page: https://developers.openai.com/api/docs/models/gpt-5.6-luna
- OpenAI GPT-5.5 Pro model page: https://developers.openai.com/api/docs/models/gpt-5.5-pro
- Anthropic pricing: https://platform.claude.com/docs/en/about-claude/pricing
- Anthropic model overview: https://platform.claude.com/docs/en/about-claude/models/overview
- Gemini pricing: https://ai.google.dev/gemini-api/docs/pricing
- Gemini generateContent response schema: https://ai.google.dev/api/generate-content