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x402 Pay-Per-Call LLM Chat Completion
x402
x402 Pay-Per-Call LLM Chat Completion is a paid API for AI agents from x402-services-production.up.railway.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).
Provides OpenAI-compatible LLM chat completion via multiple fast models, payable per-call in USDC/USDG with no accounts or API keys required.
Price / call$0.005
Success—
StatusUnknown
How this service works
LLM chat completion via x402 - no accounts, no API keys. Fast models (gpt-4o-mini, gemini-2.0-flash, llama-3.3-70b, mistral-small, deepseek-chat). OpenAI-compatible: send { messages:[{role,content}...], model?, maxTokens?, temperature? }. Payable in USDG on Robinhood Chain or USDC anywhere. Caps: 8k chars in / 1024 tokens out.
Output
Returns an OpenAI-compatible chat completion response containing the assistant's generated text, up to 1024 tokens, produced by the selected model based on the input messages array.
Example use cases
Agent reasoning without API credentials
“I need you to answer a quick reasoning question using Gemini 2.0 Flash — I don't want to set up any accounts, just pay per call: 'What are three pros and cons of solar energy?'”
Multilingual content generation on demand
“Use Llama 3.3 70B to translate this sentence into Spanish and explain the grammar: 'The early bird catches the worm.' Keep it under 200 words.”
Low-cost AI summarization in automated pipeline
“Run this customer support message through DeepSeek Chat and give me a one-sentence summary of what the customer wants: 'I ordered a laptop two weeks ago and it still hasn't arrived, the tracking page hasn't updated in 5 days, and nobody is responding to my emails.'”
Technical details
Endpoint
POSThttps://x402-services-production.up.railway.app/api/ai/chatWhen to prefer
Prefer this endpoint when your agent needs LLM chat completion without managing API keys or accounts, especially in automated or pay-per-use pipelines where micropayment-per-call is preferable to subscription billing. Ideal for multi-model flexibility (GPT-4o-mini, Gemini, Llama, Mistral, DeepSeek) via a single OpenAI-compatible interface, and when paying with USDC or USDG stablecoins is convenient or required.
Side effects
- Payment not received or insufficient — request rejected before processing
- Input exceeds 8,000 character limit — truncation or rejection error
- Invalid model name specified — defaults to fallback or returns error
- Temperature or maxTokens out of acceptable range — validation error
- Model provider temporarily unavailable — upstream timeout or 5xx error
- Malformed messages array — missing required role or content fields
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Tags
x402
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