# AgentRXI LLM Chat Completion (Llama 3.1 8B)

> AgentRXI LLM Chat Completion (Llama 3.1 8B) is a paid API for AI agents from agentrxi.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-15).

Pay-per-call LLM chat completion using Meta Llama 3.1 8B — send a prompt (and optional system message) via GET request, receive the assistant reply, no API key required.

## Facts

- Endpoint: GET https://agentrxi.com/v1/llm?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentrxi-llm-chat-completion-llama-3-1-8b-c821d50b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3TzQghOTZaw2oEE4HXPkm

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 agentrxi-llm-chat-completion-llama-3-1-8b-c821d50b
```

Example prompt: Ask the Llama 3.1 8B model: 'Summarize the pros and cons of electric vehicles in three bullet points.' Use a system message that says 'You are a concise technical writer' and limit the output to 300 tokens.

## When to prefer this

Choose this endpoint when you need a fast, low-cost, keyless LLM call for straightforward text generation or chat tasks and are fine with Llama 3.1 8B quality (8B parameter model). Prefer it over the sibling DeepSeek or QwQ endpoints when you don't need chain-of-thought reasoning or frontier-model capability and want the lowest latency and cost per call ($0.005 USDC). Ideal for agentic pipelines that need many small LLM calls without managing API credentials.

## Known failure modes

- Missing required 'prompt' query parameter returns a 400 error
- Payment not included or invalid x402 payment header returns a 402 Payment Required
- Temperature out of valid range may cause a 422 validation error
- Model overload or provider downtime may return a 503 or timeout
- Prompt exceeds context window limit may result in truncation or error

## How this service works

Pay-per-call LLM chat completion (Llama 3.1 8B, fast), no API key. Send OpenAI-style messages, get the assistant reply. Flat price per request, up to 2k output tokens. Also callable as GET with the same fields as query parameters.

## Output

Returns the assistant's reply text as a chat completion response in OpenAI-compatible format, containing the generated message content up to the requested max_tokens (default up to 2,000 output tokens).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "prompt"
     ],
     "properties": {
      "prompt": {
       "type": "string",
       "description": "User message"
      },
      "system": {
       "type": "string",
       "description": "Optional system message"
      },
      "max_tokens": {
       "type": "integer"
      },
      "temperature": {
       "type": "number"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentrxi-llm-chat-completion-llama-3-1-8b-c821d50b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentrxi.com](https://www.zero.xyz/host/agentrxi.com/llms.txt)