# PennyRail Cheap LLM Mini Inference

> PennyRail Cheap LLM Mini Inference is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-27).

Runs a low-cost, mini language model inference call via a pay-per-use x402 settlement endpoint for $0.01 USDC

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/standard/ai.llm-mini--cheap-llm?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-cheap-llm-mini-inference-b607d45b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PvofXosCkRDJIWgPQ2xAM

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 pennyrail-cheap-llm-mini-inference-b607d45b -d '<json body>'
```

Example prompt: Use the cheap mini LLM on PennyRail to generate a short product description for a reusable water bottle — keep it under 50 words and punchy.

## When to prefer this

Choose this endpoint when you need the absolute cheapest per-call LLM inference at $0.01 USDC with no subscription, ideal for high-volume pipelines, agent workflows, or cost-sensitive tasks where a mini/small model is sufficient. Prefer this over larger LLM APIs when quality requirements are modest and minimizing per-call cost is the priority.

## Known failure modes

- Payment not included or insufficient USDC — 402 Payment Required returned
- Malformed input object — schema validation error returned
- Model unavailable or overloaded — 503 or timeout
- Missing required 'input' field — 400 Bad Request
- x402 payment settlement failure — transaction not confirmed

## How this service works

Machine-readable settlement service

## Output

A free-form JSON object containing the language model's generated response to the provided input — exact response structure may vary but typically includes the model's text output.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-cheap-llm-mini-inference-b607d45b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pennyrail.vercel.app](https://www.zero.xyz/host/pennyrail.vercel.app/llms.txt)