Index onlineMerchant portal
Api Endpoint

API-existence Oracle: package

Deterministic package existence for PyPI and npm, built from real published artifacts (never LLM guesses). Negative answers and typosquat-adjacency flags carry signed proof. $0.002 USDC per check.

Open interactive test console

Offering

Provider
attester.dev
Method
POST
Offering type
Api Endpoint
Transport type
http
Category
Security
Delivery
Not provided
Pricing model
Not provided
x402 version
2

Endpoint context

URL
https://attester.dev/v1/package/exists
MIME type
Not provided
First seen
2026-10-16T02:59:31.787Z
Last seen
Tags
oracle, Packages, hallucination-check, X402, Agents

Website

Payment pricing

x402 payment terms are the authoritative price for calling this endpoint.

Payment option 1
0.002 USDC
Atomic price: 2000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Raw x402 terms
[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "2000",
    "payTo": "0x57407D691F755cAa107647718F3582a8A87467dD"
  }
]

Observed health

Status
Unreachable
Latest latency
5215 ms
Average latency
1212 ms
HTTP status
Not provided
Last checked
Reachability
85.7% over 14 checks

Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.

Input schema

{
  "body": {
    "ecosystem": "pypi",
    "name": "requests"
  },
  "bodyType": "json",
  "method": "POST",
  "type": "http"
}

Output schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "body": {
          "properties": {
            "ecosystem": {
              "enum": [
                "pypi",
                "npm"
              ],
              "type": "string"
            },
            "name": {
              "description": "Package name",
              "type": "string"
            }
          },
          "required": [
            "ecosystem",
            "name"
          ],
          "type": "object"
        },
        "bodyType": {
          "enum": [
            "json"
          ],
          "type": "string"
        },
        "method": {
          "enum": [
            "POST"
          ],
          "type": "string"
        },
        "type": {
          "const": "http",
          "type": "string"
        }
      },
      "required": [
        "type",
        "method",
        "bodyType",
        "body"
      ],
      "type": "object"
    },
    "output": {
      "properties": {
        "example": {
          "type": "object"
        }
      },
      "required": [
        "example"
      ],
      "type": "object"
    }
  },
  "required": [
    "input"
  ]
}