# EVM Calldata Decoder with Risk Flags

> EVM Calldata Decoder with Risk Flags is a paid API for AI agents from evm-canon-base.onrender.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Decodes raw EVM calldata into typed function arguments and attaches deterministic risk flags for dangerous patterns like unlimited token approvals and admin actions

## Facts

- Endpoint: POST https://evm-canon-base.onrender.com/decode
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-calldata-decoder-with-risk-flags-792c5f8d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dNG0RVz9XaktlQlsywWWb

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 evm-calldata-decoder-with-risk-flags-792c5f8d -d '<json body>'
```

Example prompt: Can you decode this EVM calldata for me — 0x095ea7b3000000000000000000000000<router>ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff — and tell me if it contains an unlimited approval or any other risk flags?

## When to prefer this

Use this endpoint when you need to programmatically decode arbitrary EVM calldata and simultaneously assess its risk profile — especially for wallet safety checks, transaction pre-screening, or DeFi approval audits. Prefer it over a generic ABI decoder when deterministic risk classification (unlimited approvals, admin actions) is required alongside decoding, without having to implement that logic yourself.

## Known failure modes

- Malformed or non-ABI-compliant hex calldata returns a parse error
- Unknown function selector not present in the ABI registry returns a null function name with undecoded args
- Calldata shorter than 4 bytes (no selector) returns an error
- Payment failure or missing x402 header results in 402 Payment Required

## How this service works

Decode EVM calldata into typed function args with deterministic risk flags (unlimited approvals, admin actions)

## Output

A structured JSON object containing the decoded function name, an array of typed arguments (with names, types, and values), and a set of deterministic risk flags indicating whether the call involves an unlimited approval, an admin/privileged action, or other dangerous patterns.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "data"
     ],
     "properties": {
      "to": {
       "type": "string"
      },
      "data": {
       "type": "string",
       "description": "0x-prefixed calldata"
      },
      "value": {
       "type": "string",
       "description": "native value in wei"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-calldata-decoder-with-risk-flags-792c5f8d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from evm-canon-base.onrender.com](https://www.zero.xyz/host/evm-canon-base.onrender.com/llms.txt)