# RedBTC GPT-5.4-mini Chat (Fixed-Price)

> RedBTC GPT-5.4-mini Chat (Fixed-Price) is a paid API for AI agents from redbtco.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-11).

Sends a chat message to a fixed gpt-5.4-mini model via a pay-per-call USDC route with no API key required, capped at 600 tokens for safe autonomous agent use.

## Facts

- Endpoint: POST https://redbtco.com/x402/redbtc/chat/5.4-mini?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/redbtc-gpt-5-4-mini-chat-fixed-price-2578d3aa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rax6OjMbGrGRamSCBxVwn

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 redbtc-gpt-5-4-mini-chat-fixed-price-2578d3aa -d '<json body>'
```

Example prompt: Use the RedBTC gpt-5.4-mini chat route to answer the following in under 200 tokens: 'What are three tips for writing clean Python code?'

## When to prefer this

Choose this endpoint when you need the lowest-cost AI chat completions without managing an OpenAI API key, especially in autonomous agent pipelines where per-call USDC billing and a hard 600-token cap provide cost safety. Prefer it over the sibling gpt-5.5 route when response quality requirements are moderate and minimizing spend is the priority.

## Known failure modes

- Payment failure if USDC balance is insufficient for the $0.001 per-call fee
- Request rejected if messages array is empty or missing required role/content fields
- Response truncated if max_tokens is set very low relative to prompt complexity
- Rate limiting or hard cap enforcement if token ceiling is exceeded
- Unpredictable output if temperature is set to extreme values (0 or 2)

## How this service works

Cheapest RedBTC agent chat route. Fixed gpt-5.4-mini, no API key, USDC per call, hard capped for safe autonomous use.

## Output

A text completion from the gpt-5.4-mini model, returned as an assistant message. The response is capped at a maximum of 600 tokens and is billed at $0.001 USDC per call via the x402 payment protocol.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Optional. RedBTC forces gpt-5.6-luna on this fixed-price route."
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "user",
       "assistant",
       "tool"
      ],
      "type": "string"
     },
     "content": {
      "type": "string"
     }
    }
   },
   "minItems": 1
  },
  "max_tokens": {
   "type": "integer",
   "maximum": 600,
   "minimum": 1
  },
  "temperature": {
   "type": "number",
   "maximum": 2,
   "minimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/redbtc-gpt-5-4-mini-chat-fixed-price-2578d3aa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from redbtco.com](https://www.zero.xyz/host/redbtco.com/llms.txt)