# Locus x402 Groq Chat Completions

> Locus x402 Groq Chat Completions is a paid API for AI agents from groq.x402.stage.paywithlocus.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Pay-per-use LLM chat completions API (Llama, Qwen, GPT-OSS models) billed at $0.005 USDC per call via x402 micropayments

## Facts

- Endpoint: POST https://groq.x402.stage.paywithlocus.com/groq/chat
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/locus-x402-groq-chat-completions-ac792853
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZXgzDyKYWiLGN6VKE4EjO

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 locus-x402-groq-chat-completions-ac792853 -d '<json body>'
```

Example prompt: Using the Locus x402 metered API, send a chat message to Llama 3.3 asking it to summarize the pros and cons of electric vehicles, set max_completion_tokens to 512, and pay the $0.005 USDC fee automatically.

## When to prefer this

Choose this endpoint when you need pay-as-you-go LLM inference with no subscription, billed automatically in USDC via x402 micropayments. Ideal for agents that need to call open-source models (Llama, Qwen, GPT-OSS) sporadically without committing to a monthly plan. Prefer this over direct Groq API when you need automatic per-call billing settled on-chain, or when building agentic pipelines that must track and authorize exact spend ceilings per request.

## Known failure modes

- Payment authorization failure if x402 header is missing or USDC balance is insufficient
- Model ID not recognized — must use one of the supported models (Llama 3.1/3.3, GPT-OSS 20B/120B, Llama 4 Scout, Qwen 3.6 27B)
- max_completion_tokens not provided — required for x402 signed authorization ceiling
- Token limit exceeded if max_completion_tokens is set too low for the requested task
- Rate limiting or capacity errors from Groq backend during high load
- Malformed messages array causes 400 validation error
- Tool definitions exceeding 128 items are rejected

## How this service works

Locus public pay-per-use API

## Output

Returns a standard OpenAI-compatible chat completion object containing the model's generated message content, optional tool call selections, token usage statistics, and finish reason. If reasoning_format is set to 'parsed' or 'raw', includes a reasoning field with chain-of-thought output. Response format can be plain text, json_object, or a validated json_schema output.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "seed": {
   "type": "number"
  },
  "stop": {
   "anyOf": [
    {
     "type": "string"
    },
    {
     "type": "array",
     "items": {}
    }
   ]
  },
  "model": {
   "type": "string"
  },
  "tools": {
   "type": "array",
   "items": {}
  },
  "top_p": {
   "type": "number"
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role"
    ],
    "properties": {
     "name": {
      "type": "string"
     },
     "role": {
      "type": "string"
     },
     "content": {
      "anyOf": [
       {
        "type": "string"
       },
       {
        "type": "array",
        "items": {
         "type": "object",
         "required": [
          "type"
         ],
         "properties": {
          "text": {
           "type": "string"
          },
          "type": {
           "type": "string"
          },
          "image_url": {
           "type": "object",
           "required": [
            "url"
           ],
           "properties": {
            "url": {
             "type": "string"
            }
           },
           "additionalProperties": true
          }
         },
         "additionalProperties": true
        }
       },
       {
        "type": "null"
       }
      ]
     },
     "tool_calls": {
      "type": "array",
      "items": {
       "type": "object",
       "additionalProperties": true
      }
     },
     "tool_call_id": {
      "type": "string"
     }
    },
    "additionalProperties": true
   }
  },
  "temperature": {
   "type": "number"
  },
  "tool_choice": {
   "anyOf": [
    {
     "type": "string"
    },
    {
     "type": "object",
     "additionalProperties": true
    }
   ]
  },
  "response_format": {
   "type": "object",
   "additionalProperties": true
  },
  "reasoning_format": {
   "type": "string"
  },
  "max_completion_tokens": {
   "type": "number"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/locus-x402-groq-chat-completions-ac792853/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from groq.x402.stage.paywithlocus.com](https://www.zero.xyz/host/groq.x402.stage.paywithlocus.com/llms.txt)