# Vextorium EVM Storage Slot Reader

> Vextorium EVM Storage Slot Reader is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-30).

Reads the raw storage value at a specific slot of any EVM smart contract, returning the hex value, decoded address, and integer representation.

## Facts

- Endpoint: POST https://api.vextorium.com/v1/evm-storage?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-evm-storage-slot-reader-c7a443ec
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BqYYzL6Xi9QPqVBr24tIg

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 vextorium-evm-storage-slot-reader-c7a443ec -d '<json body>'
```

Example prompt: Can you read storage slot 0x0 of the USDC contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base and tell me the hex value and what address it decodes to?

## When to prefer this

Choose this endpoint when you need to inspect the raw on-chain storage of any EVM smart contract at a specific slot — ideal for discovering proxy implementation addresses, reading internal state variables not exposed via ABI, verifying contract storage layouts, or auditing DeFi protocols. It covers 12 major EVM chains and returns the value in multiple decoded formats (hex, address, integer) in a single call, making it far more convenient than running your own RPC node or calling eth_getStorageAt manually.

## Known failure modes

- Invalid contract address format — returns error if contract is not a valid hex address
- Unsupported network — only base, ethereum, arbitrum, optimism, polygon, bnb, avalanche, gnosis, line, scroll, sonic, unichain are accepted
- Invalid slot format — slot must be a valid hex string
- Block number not found — if specified block does not exist on chain
- Payment failure — insufficient USDC balance or x402 payment not accepted
- Network congestion — RPC timeout when chain is under heavy load

## How this service works

558 pay-per-call data APIs for AI agents: Solana and EVM on-chain data, tokenized stocks, DeFi, Hyperliquid, economy and official statistics, FX, validation, web and developer tools. Pay in USDC via x402.

## Output

Returns the queried storage slot value in three representations: hex_value (raw 32-byte hex string), as_address (checksum-cased Ethereum address if the value is an address), and integer_value (full integer representation), along with the network, contract address, slot index, and an empty flag indicating whether the slot is unset.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "slot": {
   "type": "string"
  },
  "block": {
   "type": "string"
  },
  "network": {
   "enum": [
    "base",
    "ethereum",
    "arbitrum",
    "optimism",
    "polygon",
    "bnb",
    "avalanche",
    "gnosis",
    "line",
    "scroll",
    "sonic",
    "unichain"
   ],
   "type": "string",
   "description": "Chain (default base)"
  },
  "contract": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "slot": "0x0",
  "empty": false,
  "network": "base",
  "contract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "hex_value": "0x0000000000000000000000003abd6f64a422225e61e435bae41db12096106df7",
  "as_address": "0x3ABd6f64A422225E61E435baE41db12096106df7",
  "integer_value": "335346009260450724142082839821853564916387048951"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-evm-storage-slot-reader-c7a443ec/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)