# Base Chain Transaction Simulator & Risk Analyzer

> Base Chain Transaction Simulator & Risk Analyzer is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-31).

Simulates and analyzes Ethereum Base chain transactions, returning gas estimates, token transfers, balance changes, and a SAFE/UNSAFE verdict before execution.

## Facts

- Endpoint: GET https://kr-x402-mvp.kgy5612.workers.dev/v1/chain?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-chain-transaction-simulator-risk-analyzer-e02fa6ea
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zxBbkyB05i6AZAtZsscC0

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 base-chain-transaction-simulator-risk-analyzer-e02fa6ea
```

Example prompt: Before I send this USDC transfer on Base, simulate the transaction from 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 to contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 with calldata 0xa9059cbb... and tell me the gas cost, what token moves where, and whether it's safe to send.

## When to prefer this

Use this endpoint when an AI agent or user needs to verify a Base chain transaction's safety, cost, and outcome before committing it on-chain. Ideal for DeFi agents that must preview swaps, transfers, or multi-step contract interactions without risking funds. Prefer over generic RPC eth_call when you need decoded human-readable output (function names, token symbols, USD fees, safe/unsafe verdict) rather than raw hex. No API key required — pay $0.003 USDC per call via x402.

## Known failure modes

- Invalid Ethereum address format returns 400 with pattern validation error
- Malformed calldata hex returns error on simulation
- Simulation of calls that require on-chain state may be inaccurate if state is stale
- x402 payment failure (insufficient USDC balance) blocks the call with 402 response
- Batch of more than 5 calls rejected
- Network congestion on Base may cause stale block data

## How this service works

Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.

## Output

Returns a JSON object with: overall success boolean, verdict string (e.g. SAFE_TO_SEND), decoded function name, gas used, fee in ETH and USD, list of token transfers with amounts and symbols, balance changes per address, approval events, revert reason if any, current block number, and suggested next endpoints to call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "to": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "examples": [
        "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
       ],
       "description": "Target contract or recipient"
      },
      "data": {
       "type": "string",
       "pattern": "^0x([0-9a-fA-F]{2})*$",
       "description": "Calldata (default 0x)"
      },
      "from": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "examples": [
        "0xe4be4d0bd82d8e68203deff81f79ede0529f2617"
       ],
       "description": "Sender (signer) address"
      },
      "calls": {
       "type": "string",
       "description": "URL-encoded JSON array of up to 5 {to,data,value_eth|value} run in order from the same sender"
      },
      "value_eth": {
       "type": "string",
       "examples": [
        "0.01"
       ],
       "description": "ETH to send, decimal (default 0)"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "from": "0xe4be4d0bd82d8e68203deff81f79ede0529f2617",
  "next": [
   "/crypto/base-gas",
   "/crypto/tx-status?hash="
  ],
  "block": 53272234,
  "calls": [
   {
    "to": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
    "index": 0,
    "success": true,
    "function": "transfer(address,uint256)",
    "gas_used": 45047,
    "revert_reason": null
   }
  ],
  "chain": "base",
  "flags": [],
  "fee_eth": 5e-7,
  "fee_usd": 0.0019,
  "success": true,
  "summary": "1 call succeeds; sender sends 0.001 USDC",
  "verdict": "SAFE_TO_SEND",
  "approvals": [],
  "transfers": [
   {
    "to": "0xa587d73489f8f09d1975f1ddbb1c61c93e8fa9d7",
    "from": "0xe4be4d0bd82d8e68203deff81f79ede0529f2617",
    "token": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
    "amount": 0.001,
    "symbol": "USDC"
   }
  ],
  "gas_used_total": 45047,
  "sender_changes": {
   "USDC": -0.001
  },
  "balance_changes": {
   "0xa587d73489f8f09d1975f1ddbb1c61c93e8fa9d7": {
    "USDC": 0.001
   },
   "0xe4be4d0bd82d8e68203deff81f79ede0529f2617": {
    "USDC": -0.001
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-chain-transaction-simulator-risk-analyzer-e02fa6ea/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kr-x402-mvp.kgy5612.workers.dev](https://www.zero.xyz/host/kr-x402-mvp.kgy5612.workers.dev/llms.txt)