# Fretchen AI Assistant (LLM) Service

> Fretchen AI Assistant (LLM) Service is a paid API for AI agents from llm-agent.fretchen.eu, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

An AI chat assistant that accepts conversational prompts and returns LLM-generated text responses, billed per call via x402 USDC micropayment channels.

## Facts

- Endpoint: POST https://llm-agent.fretchen.eu/
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fretchen-ai-assistant-llm-service-4d024104
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Z1U-m7upgSNR327R1Vpew

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 fretchen-ai-assistant-llm-service-4d024104 -d '<json body>'
```

Example prompt: Ask Fretchen's AI assistant: 'What are the key differences between supervised and unsupervised machine learning?' and return the response along with how many tokens were used.

## When to prefer this

Choose this endpoint when you need a pay-per-call LLM chat service settled in USDC via x402 micropayment channels — ideal for autonomous agents or pipelines that require trustless, on-chain billing without subscription commitments. It is well-suited for scenarios where token-level usage tracking is needed for cost attribution or billing reconciliation.

## Known failure modes

- Invalid or missing 'data' field in request body returns a 400-level error
- Insufficient USDC balance or failed x402 payment settlement blocks the request
- Malformed JSON payload results in a parse error
- Network timeout if the LLM takes too long to generate a response
- Rate limiting or quota exhaustion on the provider side

## How this service works

AI chat assistant, paid via x402 batch-settlement USDC payment channels.

## Output

Returns a JSON object containing a 'message' string with the LLM's textual response, plus a 'usage' object reporting the number of prompt_tokens consumed and completion_tokens generated — useful for auditing per-call token costs and verifying the settled USDC charge.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "data"
 ],
 "properties": {
  "data": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "usage": {
   "type": "object",
   "properties": {
    "prompt_tokens": {
     "type": "integer",
     "description": "Input tokens consumed"
    },
    "completion_tokens": {
     "type": "integer",
     "description": "Output tokens generated"
    }
   },
   "description": "Token usage for this request, used to derive the settled charge"
  },
  "message": {
   "type": "string",
   "description": "The LLM's response content"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fretchen-ai-assistant-llm-service-4d024104/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from llm-agent.fretchen.eu](https://www.zero.xyz/host/llm-agent.fretchen.eu/llms.txt)