# ZeroReader Gemma 3 12B Chat Completion

> ZeroReader Gemma 3 12B Chat Completion is a paid API for AI agents from api.zeroreader.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-02).

Runs chat completions using Google's Gemma 3 12B open model, served via ZeroReader's pay-per-call API with x402 micropayment support

## Facts

- Endpoint: POST https://api.zeroreader.com/v1/ai/gemma-12b?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/zeroreader-gemma-3-12b-chat-completion-5c84064f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CvmYyIrna8WX9umlvvbWP

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 zeroreader-gemma-3-12b-chat-completion-5c84064f -d '<json body>'
```

Example prompt: Ask Gemma 3 12B to explain the trade-offs between transformer and state-space models in about 300 tokens, with a temperature of 0.5 — use the ZeroReader API.

## When to prefer this

Prefer this endpoint when you need a capable open-weight model (12B parameters) with solid reasoning ability and want pay-per-call pricing via x402 micropayments rather than a subscription. Choose it over larger siblings when latency and cost matter more than maximum capability, and over smaller models when task complexity warrants more than 3–7B parameters. Well-suited for general reasoning, summarization, and Q&A tasks that don't require specialized math or code reasoning (use DeepSeek R1 for those).

## Known failure modes

- max_tokens exceeded 4096 — request rejected with validation error
- temperature out of range (>2 or <0) — request rejected
- malformed messages array missing required role or content fields
- payment failure via x402 protocol — 402 response before inference runs
- model overload or timeout — 5xx server error
- stream mode not supported in all client configurations

## How this service works

Gemma 3 12B (Google) — Google's open model. Good at reasoning.

## Output

A chat completion object in OpenAI-compatible format containing the assistant's generated message, finish reason, and choice index. The content field holds the model's text response.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "stream": {
   "type": "boolean",
   "default": false
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "user",
       "assistant"
      ],
      "type": "string"
     },
     "content": {
      "type": "string"
     }
    }
   }
  },
  "max_tokens": {
   "type": "integer",
   "default": 1024,
   "maximum": 4096
  },
  "temperature": {
   "type": "number",
   "default": 0.7,
   "maximum": 2,
   "minimum": 0
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "id": "chatcmpl-example",
 "object": "chat.completion",
 "choices": [
  {
   "index": 0,
   "message": {
    "role": "assistant",
    "content": "I'm doing well!"
   },
   "finish_reason": "stop"
  }
 ]
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/zeroreader-gemma-3-12b-chat-completion-5c84064f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.zeroreader.com](https://www.zero.xyz/host/api.zeroreader.com/llms.txt)