Pay-per-call LLM chat API (Llama 3.1 8B), no subscription

$0.002 per call · failed calls are never charged · no account or subscription: pay per call with a card key or USDC

Send a prompt, get an answer from Meta's Llama 4 Scout (17B active, 16 experts), with an optional system prompt, up to 1,024 output tokens and adjustable temperature. Fast and cheap. Use for drafting, reasoning steps, Q&A and any quick LLM call without an AI provider account; other open models by name at /v1/chat/completions, harder reasoning at ai_chat_large.

When to use it

Run a quick completion without an account or provider key
Give an agent a cheap model for summaries or classification
Use the same key through the OpenAI-compatible /v1/chat/completions

Guide: Chat completions API, pay per call

Run it free (25 free calls) Buy credits by card (from $1) Example result (JSON)

Inputs

Name	Type	Description
`prompt` (required)	string	User prompt, up to 8,000 characters
`system`	string	Optional system prompt, up to 2,000 characters
`maxTokens`	integer	Maximum output tokens, 1-1024 (default 400)
`temperature`	number	0-1.5 (default 0.6)
`messages`	string	Optional OpenAI messages array as JSON (system, user, assistant with tool_calls, tool); replaces prompt and system. Together with tools, at most 20,000 characters
`tools`	string	Optional OpenAI tools array as JSON (function calling, up to 32 functions); the answer then carries tool_calls
`tool_choice`	string	Optional: auto, none, required, or a JSON object naming one function
`response_format`	string	Optional OpenAI response_format as JSON: {"type":"json_object"} or a json_schema

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://tools.funwords.eu/ai/chat?prompt=Explain%20x402%20in%20one%20sentence."

Or one of your 25 free calls, no key:

curl "https://tools.funwords.eu/ai/chat?prompt=Explain%20x402%20in%20one%20sentence.&trial=1"

Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum or Solana over x402; Base or Tempo over MPP) and retries.

Example result

{
  "model": "@cf/meta/llama-4-scout-17b-16e-instruct",
  "response": "x402 lets software pay for an HTTP request with a stablecoin by answering a 402 Payment Required challenge.",
  "tool_calls": [],
  "finish_reason": "stop",
  "usage": {
    "prompt_tokens": 24,
    "completion_tokens": 22,
    "total_tokens": 46
  }
}

From an AI agent (MCP)

Add the MCP server to Claude, Cursor or any MCP client. This tool is ai_chat, and the first 25 successful calls are free:

https://tools.funwords.eu/mcp

Questions

Is there an OpenAI-compatible endpoint?

Yes: /v1/chat/completions, /v1/responses and /v1/embeddings take the same payment methods.

How do I pay?

Each successful call costs $0.002; failed calls are not charged. The first 25 calls are free. Then pay with card credits (from $1; the key goes in an Authorization header or, for clients that can only fetch a URL, as api_key= in the URL) or per call in USDC over x402 or MPP. No account is needed.