# x402 LLM Gateway (erb-llm)

> x402 LLM Gateway (erb-llm) is a paid API for AI agents from api.erb-llm.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Serves OpenAI-compatible chat completions via a self-hosted 27B open-weight LLM, billed at $0.005 USDC per call over x402 with no API key required.

## Facts

- Endpoint: POST https://api.erb-llm.com/v1/chat/completions
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-llm-gateway-erb-llm-0bf3148f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cpP_uH14pjaQX-Cy3Wiz3

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 x402-llm-gateway-erb-llm-0bf3148f -d '<json body>'
```

Example prompt: Summarize the following meeting notes into 3 bullet points using the open-weight LLM — pay the per-call USDC fee automatically: 'Q3 planning meeting covered budget cuts, new product timeline, and hiring freeze.'

## When to prefer this

Choose this endpoint when you need cheap, pay-per-call LLM inference with no API key, no account registration, and no subscription — especially for agents that handle crypto (USDC on Base) natively via x402. It is ideal for privacy-sensitive workloads on a self-hosted open-weight model, or when you want OpenAI-compatible chat completions without being locked into OpenAI or Anthropic pricing tiers. Prefer alternatives like OpenAI or Anthropic if you need the very latest frontier models, guaranteed SLAs, or fine-tuned proprietary capabilities.

## Known failure modes

- Payment not included or insufficient USDC balance triggers a 402 Payment Required response
- Invalid or missing messages array returns a 400 validation error
- Requested model ID not available returns an error — check GET /v1/models for valid IDs
- Temperature out of range (0–2) or max_tokens below 1 causes validation failure
- Service unavailability or model overload may return 503 or timeout

## How this service works

OpenAI-compatible chat completions served by a self-hosted 27B open-weight LLM. Pay per call in USDC on Base via x402 - no API key or account. Use it for text generation, summarization, classification and agent tool calls that need cheap, private inference. Send a messages array (plus optional model, max_tokens, temperature); receive standard OpenAI chat.completion JSON. A free trial (POST /v1/trial) is open during promo windows.

## Output

A standard OpenAI chat.completion JSON object containing an 'id', 'object', 'created', 'model', 'choices' array (each with a 'message' object holding 'role' and 'content', plus a 'finish_reason'), and a 'usage' object showing prompt_tokens, completion_tokens, and total_tokens.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Model ID from the free GET /v1/models endpoint (e.g. qwen/qwen3.8-27b). Optional - a default chat model is chosen if omitted."
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "user",
       "assistant"
      ],
      "type": "string"
     },
     "content": {
      "type": "string"
     }
    }
   },
   "minItems": 1,
   "description": "OpenAI chat messages (system/user/assistant)."
  },
  "max_tokens": {
   "type": "integer",
   "minimum": 1,
   "description": "Optional output token ceiling. This tier caps output at 4096 tokens - higher values are clamped to 4096, not rejected. Use the long/extended tiers for bigger outputs."
  },
  "temperature": {
   "type": "number",
   "maximum": 2,
   "minimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-llm-gateway-erb-llm-0bf3148f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.erb-llm.com](https://www.zero.xyz/host/api.erb-llm.com/llms.txt)