# Synap AI Chat Completions (x402)

> Synap AI Chat Completions (x402) is a paid API for AI agents from synap.linkrra.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-23).

OpenAI-compatible chat completions using qwen3-coder-30b with pay-per-call micropayments via x402 and zero data retention

## Facts

- Endpoint: POST https://synap.linkrra.com/api/billing/x402/chat/completions?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synap-ai-chat-completions-x402-bc52c44c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XfeSHM097jVAnizZBnAle

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 synap-ai-chat-completions-x402-bc52c44c -d '<json body>'
```

Example prompt: Ask Synap to write me a Python function that parses a JSON file and filters entries where the 'status' field equals 'active' — use the qwen3-coder model and make sure nothing is stored.

## When to prefer this

Prefer this endpoint when you need OpenAI-compatible LLM inference with no subscription, pay-per-call USDC micropayments via x402, strict zero data retention, and specifically the qwen3-coder-30b model. Ideal for privacy-sensitive workloads, coding tasks, or agents that need to self-fund inference without managing API key subscriptions. Choose alternatives (e.g. OpenAI, Anthropic) if you need GPT-4/Claude models, higher throughput guarantees, or traditional API key billing.

## Known failure modes

- Insufficient USDC balance or failed x402 payment results in 402 Payment Required
- Malformed request body missing required messages field returns 400 Bad Request
- Model overload or GPU contributor unavailability may cause 503 or timeout
- Invalid OpenAI-compatible parameters (e.g. bad model name) return 400 or 422
- Network issues on Base blockchain may delay payment confirmation

## How this service works

AI powered by the people, for the people. OpenAI-compatible inference API with zero data retention — qwen3-coder-30b at $0.0675/1M in, $0.27/1M out. Contribute your GPU, earn credits.

## Output

Returns an OpenAI-compatible chat.completion JSON object with the assistant's message content, token usage counts (prompt, completion, total), a unique completion ID, and a payment receipt containing the Base network transaction hash and USD amount paid.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "enum": [
    "auto",
    "qwen/qwen3-vl-30b-a3b-instruct",
    "qwen/qwen3-30b-a3b",
    "qwen3-coder-30b",
    "gpt-oss-20b",
    "gemma-4-26b-a4b-it"
   ],
   "type": "string",
   "description": "\"auto\" = cheapest of our self-hosted models that fits, or name one."
  },
  "stream": {
   "type": "boolean",
   "default": false,
   "description": "true = stream OpenAI-format Server-Sent Events."
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "user",
       "assistant",
       "tool"
      ],
      "type": "string"
     },
     "content": {
      "description": "Text, or an array of OpenAI content parts."
     }
    }
   },
   "examples": [
    [
     {
      "role": "user",
      "content": "Write a Python function that reverses a string"
     }
    ]
   ],
   "minItems": 1,
   "description": "OpenAI-format chat history, oldest first: [{role, content}]."
  },
  "max_tokens": {
   "type": "integer",
   "default": 4096,
   "maximum": 4096,
   "minimum": 1,
   "description": "Completion token cap. The price is quoted for the prompt plus this cap."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "chatcmpl-...",
  "usage": {
   "total_tokens": 0,
   "prompt_tokens": 0,
   "completion_tokens": 0
  },
  "object": "chat.completion",
  "choices": [
   {
    "message": {
     "role": "assistant",
     "content": "..."
    }
   }
  ],
  "payment": {
   "network": "eip155:8453",
   "paidUsd": 0,
   "transaction": "0x..."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synap-ai-chat-completions-x402-bc52c44c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from synap.linkrra.com](https://www.zero.xyz/host/synap.linkrra.com/llms.txt)