Pay-per-call chat completion on the nano tier
Pay-per-call chat completion on the nano tier. One request returns one assistant message, limited to 1000 input and 256 output tokens, at 0.006 USDC per call on Base. Payment settles after the response is produced. A client nonce header makes a retry free of a second charge.
Answeringour last check, 2026-10-18
1 of 1checks answered this week
570 msmedian answer time
$0.006listed price per call
$0.006price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://pay.omnidev.tech/x402/chat-nano
| Category | Market data |
|---|---|
| Provider host | pay.omnidev.tech |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-18 | valid payment request | 402 | $0.006 | 570 ms |
Example input (from the provider)
{
"body": {
"max_tokens": 64,
"messages": [
{
"content": "Summarize the x402 payment flow in one sentence.",
"role": "user"
}
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"max_tokens": {
"description": "Upper bound on output tokens.",
"maximum": 256,
"minimum": 1,
"type": "integer"
},
"messages": {
"description": "Conversation, oldest first.",
"items": {
"additionalProperties": false,
"properties": {
"content": {
"description": "Message text.",
"type": "string"
},
"role": {
"enum": [
"system",
"developer",
"user",
"assistant"
],
"type": "string"
}
},
"required": [
"role",
"content"
],
"type": "object"
},
"maxItems": 64,
"minItems": 1,
"type": "array"
},
"model": {
"description": "auto selects the tier model.",
"enum": [
"auto",
"llama-3.1-8b",
"kimi-k3"
],
"type": "string"
},
"prompt": {
"description": "Shorthand for one user message; used when messages is absent.",
"type": "string"
}
},
"type": "object"
},
"bodyType": {
"enum": [
"json"
],
"type": "string"
},
"headers": {
"additionalProperties": {
"type": "string"
},
"properties": {
"X-Omni-Client-Nonce": {
"description": "Present on every request that carries a payment credential: a random base64url value, 22-128 characters, new for each payment. A paid request without it is answered 400 client_nonce_required and is not charged.",
"pattern": "^[A-Za-z0-9_-]{22,128}$",
"type": "string"
}
},
"type": "object"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"facilitator_tx": {
"type": "string"
},
"ok": {
"type": "boolean"
},
"result": {
"properties": {
"choices": {
"type": "array"
},
"id": {
"type": "string"
},
"model": {
"type": "string"
},
"object": {
"type": "string"
},
"usage": {
"type": "object"
}
},
"required": [
"choices"
],
"type": "object"
},
"settled": {
"type": "boolean"
}
},
"required": [
"ok",
"result"
],
"type": "object"
},
"type": {
"const": "json",
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}