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PennyRail OpenAI Token Counter
x402
PennyRail OpenAI Token Counter is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).
Counts the number of OpenAI tokens in a given text input using OpenAI-compatible tokenization
Price / call$0.001
Success—
StatusUnknown
How this service works
Machine-readable settlement service
Output
Returns a JSON object containing the token count for the submitted text, computed using OpenAI-compatible tokenization (tiktoken). The response indicates how many tokens the input consumes when processed by OpenAI language models.
Example use cases
Pre-flight prompt length check
“Before I send this system prompt to GPT-4, can you count how many OpenAI tokens it uses so I know if it fits in the context window? Here's the text: 'You are a helpful assistant that answers questions about science and technology in a concise, friendly manner.'”
Billing cost estimation
“I need to estimate how much this batch of user messages will cost with OpenAI. Can you count the tokens in this text so I can multiply it by the per-token price? Text: 'Please summarize the following article and highlight the three most important points for a business audience.'”
Chunking strategy planning
“I'm splitting a long document into chunks to embed with OpenAI. Can you count the tokens in this chunk so I know if it's under 8191 tokens? The chunk is: 'Machine learning is a subset of artificial intelligence that enables systems to learn and improve from experience without being explicitly programmed.'”
Technical details
Endpoint
POSThttps://pennyrail.vercel.app/api/p/nano/text.token-count--openai-tokensWhen to prefer
Choose this endpoint when you need a fast, pay-per-use token count against OpenAI's tokenization scheme (tiktoken) without spinning up a local library. Ideal for agents that need to check prompt length, estimate costs, or plan chunking strategies on the fly, especially in serverless or constrained environments where installing tiktoken is not practical.
Side effects
- Missing or malformed 'input' object returns a validation error
- Empty text input may return zero tokens or an error
- Payment not settled via x402 protocol results in 402 Payment Required
- Extremely large inputs may exceed processing limits
- Network timeout for unusually long text bodies
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Output
Schema · Response
{
"type": "object",
"additionalProperties": true
}Tags
x402
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