# Delx Commerce — EVM Calldata Size Bytes

> Delx Commerce — EVM Calldata Size Bytes is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Computes the byte length of an EVM calldata hex string and validates its format, returning the byte count and shape validity.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/evm-calldata-size-bytes?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-evm-calldata-size-bytes-9f76c058
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jc0JvP-i_LsNt6zfUkSs1

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 delx-commerce-evm-calldata-size-bytes-9f76c058 -d '<json body>'
```

Example prompt: How many bytes is this EVM calldata: '0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9000000000000000000000000000000000000000000000000000000000000000a'? Also tell me if the shape is valid.

## When to prefer this

Use this endpoint when you need a fast, verifiable, pay-per-use check of EVM calldata byte length and format validity without any state retention — ideal for preflight validation before submitting Ethereum transactions, gas estimation workflows, or debugging malformed calldata. Prefer this over building your own parser when auditability (via SHA256 evidence) and agent-native micropayment billing via USDC/x402 are desirable.

## Known failure modes

- Calldata exceeding 8192 characters will be rejected
- Non-hex or malformed input strings may result in shape_valid: false rather than an error
- Missing or empty calldata field returns a validation error
- Network or payment failure via x402 protocol prevents the call from completing

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object containing the original calldata, the computed byte count as an integer, a boolean shape_valid flag indicating whether the calldata is correctly formatted, the operation name, status ('pass'), and an evidence block with retained (false), input SHA256 hash, and external call count (0) confirming in-memory-only processing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "calldata": {
   "type": "string",
   "maxLength": 8192,
   "description": "Calldata supplied to EVM Calldata Size Bytes; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "calldata": "0x1234abcd",
   "byte_count": 4,
   "shape_valid": true
  },
  "schema": "delx/util-evm-calldata-size-bytes/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "6ffdb637cbb0ee3342cdd21ba540914ee72f80a467cba5a39651837c42e42662",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_calldata_size_bytes"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-evm-calldata-size-bytes-9f76c058/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)