# ARAKEL Machine Evidence Network - Machine Check

> ARAKEL Machine Evidence Network - Machine Check is a paid API for AI agents from proof.arakelproof.space, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Checks an entity against official sources (e.g. OFAC) and returns a cryptographically signed OBSERVED/NOT_OBSERVED/INCONCLUSIVE evidence proof.

## Facts

- Endpoint: GET https://proof.arakelproof.space/v1/machine/check
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/arakel-machine-evidence-network-machine-check-a8c83a8b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ye0XAqIzVi0YXC6iIwLcA

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability arakel-machine-evidence-network-machine-check-a8c83a8b
```

Example prompt: Can you run an ARAKEL machine evidence check on the entity 'Acme Trading LLC' to see if they appear on OFAC or other official watchlists, and get me a signed proof I can keep on file?

## When to prefer this

Choose this endpoint when you need cryptographically signed, machine-verifiable compliance evidence (OBSERVED/NOT_OBSERVED/INCONCLUSIVE) from official sources such as OFAC, rather than a simple name-match lookup. It is particularly valuable when you need a signed proof artifact for audit trails, when you need NOT_OBSERVED proofs (not just positive hits), or when you want to screen counterparties across multiple official sources in one call. The tiered pricing ($0 preflight, $0.005 quick check, $0.01 full check) makes it cost-efficient to run at scale.

## Known failure modes

- Entity identifier not recognized or too ambiguous — returns INCONCLUSIVE
- Queried source temporarily unavailable — may return error or INCONCLUSIVE
- Invalid or missing entity parameter — returns 400-level error
- Payment not provided or insufficient — request rejected before check runs
- Rate limiting on batch checks if quota exceeded

## How this service works

Machine-verifiable official-source evidence with free preflight and x402 USDC payments on Base.

## Output

A JSON object containing a result field (OBSERVED, NOT_OBSERVED, or INCONCLUSIVE), the source that was queried (e.g. OFAC), a schema identifier (arakel.machine-evidence.v2), and a cryptographic Ed25519 signature attesting to the result, suitable for audit and compliance records.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "source",
      "from",
      "to"
     ],
     "properties": {
      "to": {
       "type": "string",
       "format": "date-time"
      },
      "from": {
       "type": "string",
       "format": "date-time"
      },
      "term": {
       "type": "string",
       "description": "Optional search term"
      },
      "entity": {
       "type": "string",
       "description": "Company, person, entity, ticker, CIK, recipient, or organization"
      },
      "source": {
       "enum": [
        "federal-register",
        "ofac",
        "fda",
        "usaspending"
       ],
       "type": "string",
       "description": "Currently enabled official source adapter"
      },
      "event_type": {
       "type": "string",
       "description": "listing_present, listing_added, recall, award, publication, etc."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": "OBSERVED|NOT_OBSERVED|INCONCLUSIVE",
  "schema": "arakel.machine-evidence.v2",
  "source": {
   "id": "ofac"
  },
  "signature": {
   "alg": "Ed25519"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/arakel-machine-evidence-network-machine-check-a8c83a8b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from proof.arakelproof.space](https://www.zero.xyz/host/proof.arakelproof.space/llms.txt)