# SYNTHORA LLM Gateway SMART

> SYNTHORA LLM Gateway SMART is a paid API for AI agents from llm-smart.hergertsynthora.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

OpenAI-compatible LLM chat completions endpoint with pay-per-call pricing via x402, automatic upstream failover, and large open-source models (Llama-3.3-70b class)

## Facts

- Endpoint: POST https://llm-smart.hergertsynthora.com/v1/chat/completions
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-llm-gateway-smart-58531ca0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_D3eb99ouemIbD02xfxGx_

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 synthora-llm-gateway-smart-58531ca0 -d '<json body>'
```

Example prompt: Ask the SYNTHORA SMART gateway to explain the difference between supervised and unsupervised learning in 3 sentences, using the Llama-70b model — keep the response under 300 tokens.

## When to prefer this

Choose this endpoint when you need a large open-source LLM (Llama-3.3-70b class) without committing to an API key or subscription — ideal for agents that pay per call using x402 micropayments on Base. It is especially suitable for serverless or ephemeral agents that need OpenAI-compatible chat completions with built-in upstream failover, Ed25519-signed responses for auditability, and a very low per-call cost of $0.005 USDC.

## Known failure modes

- Payment failure if x402 micropayment of 0.005 USDC on Base is not completed or wallet has insufficient balance
- Upstream model unavailability — though automatic failover is built in, all upstream providers may occasionally be degraded
- max_tokens cap at 1024 — requests asking for more will be silently capped
- Invalid message format — if neither 'messages' array nor 'prompt' string is provided, the request will likely fail
- Rate limiting or abuse throttling if too many calls are made in rapid succession

## How this service works

SYNTHORA LLM Gateway SMART: OpenAI-compatible /v1/chat/completions pay-per-call, no API keys. Large free-tier models (llama-3.3-70b class) with automatic upstream failover, Ed25519-signed. 0.005 USDC via x402 on Base. POST {"messages":[{"role":"user","content":"..."}]} (or {"prompt":"..."}).

## Output

An OpenAI-compatible chat completion response containing the assistant's generated message, including the role, content, finish reason, and token usage. The response is Ed25519-signed by SYNTHORA for authenticity verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Etiqueta aceptada; el tier fija el modelo real"
  },
  "prompt": {
   "type": "string",
   "description": "Atajo sin messages"
  },
  "system": {
   "type": "string",
   "description": "System prompt opcional (con prompt)"
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object"
   },
   "description": "OpenAI chat messages"
  },
  "max_tokens": {
   "type": "integer",
   "description": "Max output tokens (default 256, cap 1024)"
  },
  "temperature": {
   "type": "number"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "llm_smart",
  "result": {},
  "receipt": {
   "alg": "ed25519"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-llm-gateway-smart-58531ca0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from llm-smart.hergertsynthora.com](https://www.zero.xyz/host/llm-smart.hergertsynthora.com/llms.txt)