# EVM ERC-20 transferFrom Calldata Builder

> EVM ERC-20 transferFrom Calldata Builder 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 2026-09-14).

Encodes delegated ERC-20 transferFrom calldata for on-chain execution, spending a previously granted allowance to move tokens from one address to another.

## Facts

- Endpoint: POST https://evm-canon-base.onrender.com/encode/transfer-from
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-erc-20-transferfrom-calldata-builder-814f98af
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tqIfq9L1GBbCSCO7uWaSO

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-erc-20-transferfrom-calldata-builder-814f98af -d '<json body>'
```

Example prompt: Build the transferFrom calldata to pull 500 USDC (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) from 0xOwnerAddress to 0xRecipientAddress — the spender is 0xSpenderAddress.

## When to prefer this

Choose this endpoint when you need to programmatically build ERC-20 transferFrom calldata without running a local ABI encoder or Web3 library. It is especially useful for agents operating in environments without EVM tooling, or when constructing transactions for delegated token transfers where a spender allowance has already been approved via approve() or permit().

## Known failure modes

- Invalid or non-checksum Ethereum address returns a 400 error
- Amount not parseable as a uint256 returns encoding error
- Missing required fields (from, to, amount, token) returns validation error
- Network or service unavailability returns 5xx
- Payment not provided or insufficient returns 402 Payment Required

## How this service works

Build delegated ERC-20 transferFrom calldata

## Output

A hex-encoded ABI calldata string representing the transferFrom(address from, address to, uint256 amount) function call, ready to be submitted as the 'data' field of an EVM transaction to the relevant ERC-20 token contract.

## 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": [
      "args"
     ],
     "properties": {
      "args": {
       "type": "object",
       "description": "arguments keyed by parameter name"
      },
      "chain": {
       "description": "chain name, alias or numeric chainId"
      },
      "token": {
       "type": "string",
       "description": "symbol or contract address"
      },
      "value": {
       "type": "string",
       "description": "native value in wei"
      },
      "function": {
       "type": "string",
       "description": "name or full signature (generic route only)"
      }
     }
    },
    "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-erc-20-transferfrom-calldata-builder-814f98af/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)