API Documentation

Ingestion API Reference.

acost provides a high-performance REST API to track AI costs from any backend environment. No SDK required—just a simple POST request.

Create API Key

Configuration

Environment Variables

Store these keys in your secure backend configuration. Never expose your API key in client-side code.

.env configuration

ACOST_BASE_URL=https://tracker-acost.vercel.app
ACOST_API_KEY=acost_your_secret_key

Official Support

We provide high-precision tracking for the following providers.

OpenAI

Anthropic

Google

OpenRouter

xAI

DeepSeek

Qwen

Xiaomi

Dual-Source Pricing

We track both official rates via PriceToken.ai and OpenRouter market rates. Our engine automatically switches to OpenRouter pricing if provider: "openrouter" is sent.

Custom Providers

You can use any provider, but we recommend sending a manual estimatedCost for unlisted vendors to ensure absolute accuracy.

Request Schema

Every event requires the following core fields for precise tracking.

Field	Type	Status
`userId` Unique identifier for your application user.	string	Required
`model` Exact model ID used (e.g. gpt-4o).	string	Required
`feature` Grouping tag for your product features.	string	Required
`prompt` The input text sent to the AI model.	string	Required
`responseContent` The generated text response from the model.	string	Required
`inputTokens` Prompt token count.	number	Required
`outputTokens` Completion token count.	number	Required
`rawResponse` Full provider JSON response (crucial for auditing).	object	Required
`provider` AI vendor. Defaults to PriceToken.ai rates if omitted.	string	Optional
`latency` Request duration in milliseconds.	number	Optional
`estimatedCost` Manual cost override. If omitted, acost will calculate this using model metadata.	number	Optional

Payload Formats

Single Event

Pass a single object under the event key.

Batch (Up to 100)

Pass an array of objects under the events key.

Responses

200 OKAccepted

400 Bad RequestSchema Error

401 UnauthorizedInvalid Key

Implementation Examples

Ready-to-use snippets for your backend environment.

cURL Request

curl -X POST https://tracker-acost.vercel.app \
  -H "Content-Type: application/json" \
  -H "x-api-key: acost_your_secret_key" \
  -d '{
    "event": {
      "userId": "user_123",
      "model": "gpt-4o-mini",
      "feature": "chat-answer",
      "prompt": "What is the capital of France?",
      "responseContent": "The capital of France is Paris.",
      "inputTokens": 1200,
      "outputTokens": 280,
      "latency": 842,
      "rawResponse": { "id": "chatcmpl-123", "object": "chat.completion", "usage": { "prompt_tokens": 1200, "completion_tokens": 280, "total_tokens": 1480 } }
    }
  }'

Secure SSL Ingestion Enabled