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Agentshelf Heuristic Token Counter
x402
Agentshelf Heuristic Token Counter is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).
Estimates token count for text using heuristic methods (chars/4, word count, or regex) without invoking any LLM or tokenizer
Price / call$0.001
Success—
StatusUnknown
How this service works
Call when an agent needs a heuristic token count for text (not a model tokenizer). No LLM. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/token-count first.
Output
Returns a numeric token count estimate based on the selected heuristic method (chars4 divides character count by 4, words counts whitespace-delimited tokens, regex applies a pattern-based split). No LLM or external model is invoked.
Example use cases
Prompt length guard before LLM call
“Before I send this system prompt to GPT, estimate how many tokens it is using the chars4 method so I know if it fits in the context window.”
Word-based token estimate for document chunking
“I'm splitting a document into chunks — can you use the words heuristic to estimate the token count for each chunk's text so I can keep them under 512 tokens?”
Regex-based token count for input validation
“Use the regex counting method to estimate how many tokens are in this user-submitted comment before I decide whether to accept it: 'I really loved the product, it changed my daily routine completely and I tell everyone about it.'”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/token-count?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a fast, cheap, model-agnostic token estimate without invoking an actual LLM tokenizer. Ideal for pre-flight checks before sending prompts to paid LLM APIs, or for lightweight agents that need rough token budgeting. Try the free POST /v1/sandbox/token-count endpoint first; only call this paid endpoint if the sandbox is unavailable or rate-limited.
Side effects
- Text exceeds 100,000 character limit — request rejected
- Text field is empty or missing — validation error
- Invalid method enum value supplied — request rejected
- Payment of $0.001 USDC not completed — 402 Payment Required response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| text | string | Text to count. This is not a model tokenizer. |
| method | string | Count method: chars4 (ceil of characters/4), words (whitespace), or regex. Default chars4. |
Tags
x402
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