# Toll402 LLM Chat Completion Gateway

> Toll402 LLM Chat Completion Gateway is a paid API for AI agents from toll402.dev, paid per call via x402, $0.00115/call, status unknown (last checked 2026-09-15).

Sends a chat completion request to an LLM via the Toll402 pay-per-call gateway, billed in USDC via x402 with no signup or API key required.

## Facts

- Endpoint: POST https://toll402.dev/v1/x/2dc439e9109c
- Price: $0.00115/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/toll402-llm-chat-completion-gateway-4f4ff8a5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xa0RZomeqdXge_WpEAW-P

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 toll402-llm-chat-completion-gateway-4f4ff8a5 -d '<json body>'
```

Example prompt: Use Toll402 to send these messages to gpt-4o with a max of 512 tokens and pay per call in USDC — no API key needed: system: 'You are a helpful assistant.', user: 'Summarize the key points of the Paris Agreement.'

## When to prefer this

Choose Toll402 when you need a permissionless, no-signup LLM chat completion endpoint that bills per call in USDC via the x402 protocol — ideal for AI agents operating with a crypto wallet, pipelines that need to avoid API key management, or applications requiring micropayment-native LLM access. Prefer this over OpenAI or Anthropic direct APIs when you want a single gateway that aggregates multiple models without credential overhead.

## Known failure modes

- Insufficient USDC balance triggers 402 Payment Required before the LLM call is made
- Invalid or unsupported model name returns an error from the gateway
- Malformed messages array (missing role or content fields) causes a validation error
- max_tokens set too low may result in truncated or incomplete responses
- Network timeout if the upstream LLM provider is slow to respond
- x402 payment protocol not supported by the calling client causes payment failure

## How this service works

The OpenRouter for AI-agent tools: one gateway, one wallet, every capability. Built-in tools, forged tools, a global verified business directory and 2,000+ aggregated x402 services, all paid per call in USDC via x402 (HTTP 402). No signup, no API key.

## Output

Returns a standard LLM chat completion response containing the assistant's generated message, along with token usage metadata and the model used, matching the OpenAI-compatible chat completion response format.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "messages"
 ],
 "properties": {
  "model": {
   "type": "string"
  },
  "messages": {
   "type": "array"
  },
  "max_tokens": {
   "type": "integer"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/toll402-llm-chat-completion-gateway-4f4ff8a5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from toll402.dev](https://www.zero.xyz/host/toll402.dev/llms.txt)