# LLM Token Count Estimator & Cost Projector

> LLM Token Count Estimator & Cost Projector is a paid API for AI agents from api.24klabs.ai, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).

Estimates token count for a text string using heuristic (character- and word-based) methods, then projects per-model input costs for LLM budgeting.

## Facts

- Endpoint: POST https://api.24klabs.ai/api/llm-token-estimate
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/llm-token-count-estimator-cost-projector-d8407120
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3_AIJXjXCdE1OIsbvua25

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability llm-token-count-estimator-cost-projector-d8407120 -d '<json body>'
```

Example prompt: Can you give me a heuristic token count estimate and a per-model cost projection for this text: 'Large language models are transforming software development by enabling natural language interfaces to complex systems.' — I want to see what it would cost to send this as input to a few different models.

## When to prefer this

Use this endpoint when you need a fast, cheap heuristic token count and multi-model cost estimate without spinning up a local tokenizer library. Ideal for budgeting pipelines, pre-flight checks, or agentic workflows that need to gauge LLM API costs before making actual calls. Not suitable when exact token counts are required (e.g. for precise context-window boundary checking) — for that, use a model-specific BPE tokenizer.

## Known failure modes

- Empty or missing text input returns a validation error
- Extremely large payloads may time out or be rejected
- Results are approximate — not exact BPE tokenizer output, so actual token counts may differ from real tokenizer results
- Unsupported or unrecognized model names may not appear in cost projections

## How this service works

Heuristic token-count estimate for a text (character- and word-based) plus an illustrative per-model input-cost projection for budgeting. Not an exact BPE tokenizer.

## Output

Returns a heuristic token count estimate (based on character and word counts, not exact BPE tokenization), along with an illustrative breakdown of expected input costs across multiple popular LLM models, useful for budgeting and planning.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chars": 66,
  "words": 11,
  "costs_usd": {
   "claude-sonnet": 0.000042
  },
  "tokens_estimate": 14
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/llm-token-count-estimator-cost-projector-d8407120/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.24klabs.ai](https://www.zero.xyz/host/api.24klabs.ai/llms.txt)