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Agent402.Tools Premium Responses (LLM Inference via x402)
x402
Agent402.Tools Premium Responses (LLM Inference via x402) is a paid API for AI agents from agent402.tools, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-15).
Routes a prompt to an allowlisted LLM (OpenAI Responses API-compatible) and streams or returns the completion, paid per-call in USDC via x402 with no API key required.
Price / call$0.5
Success—
StatusUnknown
How this service works
OpenAI Responses API over x402 - point the OpenAI SDK's responses.create() (or the OpenAI Agents SDK) at base_url https://agent402.tools/v1/premium and pay $0.50 per call in USDC, no API key, no signup. Same models, caps and price as this tier's /chat/completions route; any model here is served through the Responses wire.
Output
Returns an OpenAI Responses API-compatible JSON object containing the assistant's output message(s), the model used, input/output/total token counts, a response ID, and a completion status. In streaming mode, delivers SSE events (response.created through response.completed) with incremental content deltas.
Example use cases
Keyless LLM call for an autonomous agent
“My agent needs to call GPT-4o-mini to answer 'What are the main differences between x402 and traditional API billing?' — do it without any API key, just pay 0.5 USDC per call using my wallet and return the full text response.”
Structured JSON extraction from unstructured text
“Run this through an LLM and give me back a JSON object with keys 'company', 'revenue', and 'year' extracted from: 'Acme Corp reported $4.2B in revenue for fiscal 2024.' — use auto model selection and format the output as json_object.”
Reasoning-heavy code review with high effort
“I want to review this Python snippet for security issues — pass it to a reasoning model with high reasoning effort, include system instructions saying 'You are a senior security engineer', and stream the response: def login(user, pwd): return db.query(f'SELECT * FROM users WHERE u={user} AND p={pwd}')”
Technical details
Endpoint
POSThttps://agent402.tools/v1/premium/responsesWhen to prefer
Choose this endpoint when you need LLM inference without signing up for API keys or managing subscriptions — ideal for AI agents that authenticate via a crypto wallet and pay per call in USDC using the x402 protocol. Prefer it over OpenAI or OpenRouter direct when you want wallet-as-identity, zero-signup access to 500+ tools and models, or when your agent stack is already x402-native. It is especially valuable for multi-model routing (OpenRouter naming), controllable reasoning effort, zero-data-retention requirements, and streaming completions in agentic pipelines.
Side effects
- Payment not included or insufficient USDC — 402 Payment Required returned
- Model ID not on allowlist for the caller's tier — rejected with model error
- Inner dimension mismatch in tool call parameters — function_call validation error
- max_output_tokens clamped to tier cap silently — output may be truncated
- Zero-data-retention filter excludes requested model — provider unavailable
- Malformed input array (missing role or content) — 400 Bad Request
- Streaming connection dropped mid-response — partial SSE stream, no completed event
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| zdr | boolean | Optional - zero-data-retention providers only |
| text | object | Optional {format: {type: "text"|"json_schema"|"json_object", ...}} |
| input | — | A string, or an array of input items ({role, content} messages with input_text / input_image parts, function_call, function_call_output) |
| model | string | Model id (OpenRouter naming) - allowlisted per tier; omit (or "auto") on the auto tier |
| tools | array | Optional function tools ({type:"function", name, parameters}); server-side tools are not served |
| stream | boolean | Responses SSE events (response.created … response.completed) |
| reasoning | object | Optional {effort: "none"|"minimal"|"low"|"medium"|"high"|"xhigh"|"max"} - reasoning tokens count against max_output_tokens |
| instructions | string | Optional system/developer instructions |
| max_output_tokens | integer | Optional output cap (clamped to the tier cap) |
Output
Schema · Response
{
"type": "json",
"example": {
"id": "resp_…",
"model": "openai/gpt-4o-mini",
"usage": {
"input_tokens": 14,
"total_tokens": 32,
"output_tokens": 18
},
"object": "response",
"output": [
{
"id": "msg_…",
"role": "assistant",
"type": "message",
"status": "completed",
"content": [
{
"text": "x402 is an HTTP-native way for agents to pay per request with USDC.",
"type": "output_text",
"annotations": []
}
]
}
],
"status": "completed"
}
}Tags
x402
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