# VulnHunt Smart Contract Security Snapshot API

> VulnHunt Smart Contract Security Snapshot API is a paid API for AI agents from vulnhunt-agent-api-production.up.railway.app, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Returns a read-only historical security intelligence snapshot for a smart contract, including risk score, bytecode hash, source verification status, and evidence metadata.

## Facts

- Endpoint: GET https://vulnhunt-agent-api-production.up.railway.app/v1/contracts/%7Bchain_id%7D/%7Baddress%7D/snapshot
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vulnhunt-smart-contract-security-snapshot-api-5ea3fec5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_efwzSXaAh48TILMs6MKty

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 vulnhunt-smart-contract-security-snapshot-api-5ea3fec5
```

Example prompt: Can you pull a security snapshot for the contract at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum (chain ID 1) and tell me the risk level and whether the source code is verified?

## When to prefer this

Choose this endpoint when you need a fast, read-only historical security intelligence snapshot for a specific smart contract on a known chain, particularly for pre-transaction due diligence or DeFi risk screening. It is ideal for agents that need machine-readable risk scores and bytecode/source verification status without requiring a full on-chain audit. Prefer this over general blockchain explorers when you need structured security signals rather than raw transaction data.

## Known failure modes

- Contract address not found on specified chain — returns empty or 404 response
- Invalid chain_id or unsupported blockchain — returns error
- Address is an EOA (externally owned account), not a contract — is_contract will be false
- No historical data available for the contract — may return null risk score
- Malformed address format — returns 400 bad request
- Payment not fulfilled (x402 protocol) — returns 402 Payment Required

## How this service works

Read-only historical smart-contract security intelligence for autonomous agents.

## Output

Returns a JSON object containing: a risk object with level (e.g. 'low'), numeric score, and disclaimer flags (not_an_audit, not_a_vulnerability_verdict); a contract object with address, is_contract boolean, bytecode SHA256 hash, and verified_source boolean; an evidence object with source_verified and bytecode_present booleans; and a schema_version string.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   },
   "additionalProperties": true
  }
 },
 "additionalProperties": false
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "risk": {
   "level": "low",
   "score": 0,
   "not_an_audit": true,
   "not_a_vulnerability_verdict": true
  },
  "contract": {
   "address": "0x0000000000000000000000000000000000000000",
   "is_contract": true,
   "bytecode_sha256": "<sha256>",
   "verified_source": true
  },
  "evidence": {
   "source_verified": true,
   "bytecode_present": true
  },
  "schema_version": "0.3"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vulnhunt-smart-contract-security-snapshot-api-5ea3fec5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from vulnhunt-agent-api-production.up.railway.app](https://www.zero.xyz/host/vulnhunt-agent-api-production.up.railway.app/llms.txt)