# x402 LLM Gateway — Long-Form Tier

> x402 LLM Gateway — Long-Form Tier is a paid API for AI agents from api.erb-llm.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Runs long-form chat completions (up to 8,192 output tokens) on a self-hosted 27B open-weight LLM, billed at $0.05 USDC per call via x402 on Base with no API key required.

## Facts

- Endpoint: POST https://api.erb-llm.com/v1/long
- Price: $0.05/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-long-form-tier-fe7a5d99
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bF4t3hb7HwC3G-1VoMsld

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-long-form-tier-fe7a5d99 -d '<json body>'
```

Example prompt: Write me a detailed 2,000-word analysis of the pros and cons of renewable energy adoption for developing economies — use a neutral tone and organize it into clear sections; pay for the call in USDC.

## When to prefer this

Choose this endpoint when you need outputs longer than 1,024 tokens — such as full articles, detailed summaries, multi-section reports, or thorough explanations — and want to pay per call in USDC without an API key or account. Prefer the cheaper /v1/chat/completions (1,024-token) tier for short answers, tool calls, and classification tasks. Use the extended tier if you need outputs beyond 8,192 tokens.

## Known failure modes

- Payment not included or insufficient USDC — request rejected with 402 Payment Required
- messages array missing or empty (minItems:1 violated) — 422 Unprocessable Entity
- max_tokens exceeds 8,192 — clamped silently to 8,192, not an error
- Model ID not found in /v1/models — may fall back to default or return 400
- Network or inference timeout on very long generations — 504 or partial response
- Malformed message roles (not system/user/assistant) — 422 validation error

## How this service works

Long-form tier of the x402 LLM gateway: same self-hosted 27B open-weight LLM with an 8,192-token output ceiling for summarization, drafting and multi-paragraph answers. Pay per call in USDC on Base via x402 - no API key or account. OpenAI-compatible: send a messages array, receive standard chat.completion JSON. Use the cheaper /v1/chat/completions tier (4,096 tokens) for short answers and tool calls.

## Output

Returns a standard OpenAI-format chat.completion JSON object containing the assistant's generated message, finish reason, token usage counts (prompt and completion), and model identifier. Output text can be up to 8,192 tokens; requests specifying higher max_tokens values are silently clamped to 8,192.

## 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 8192 tokens - higher values are clamped to 8192, 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-long-form-tier-fe7a5d99/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)