# EVM Contract Storage Slot Reader

> EVM Contract Storage Slot Reader is a paid API for AI agents from store.agentexchange.work, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Reads the raw value stored at a specific storage slot of any EVM smart contract on Base, Ethereum, Optimism, Arbitrum, Polygon, or Gnosis.

## Facts

- Endpoint: GET https://store.agentexchange.work/chain/storage
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-contract-storage-slot-reader-eef644c3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aNGdoLe8zxqDCoRstgYqM

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-contract-storage-slot-reader-eef644c3
```

Example prompt: What's the raw value stored at storage slot 0x2 of the contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum?

## When to prefer this

Use this endpoint when you need low-level, raw storage slot access to an EVM smart contract without requiring an ABI or decoded method call. Ideal for smart contract auditing, verifying storage layouts, reading proxy implementation slots (e.g. EIP-1967), or inspecting state variables directly by slot number across multiple EVM chains. Prefer this over ABI-decoded calls when the ABI is unavailable or when you need to confirm raw storage rather than interpreted values.

## Known failure modes

- Invalid contract address format returns an error — ensure address is a valid 0x-prefixed hex string
- Invalid or out-of-range slot value may return zero value or error — verify slot is valid hex or decimal
- Unsupported chain identifier returns an error — must be one of base, ethereum, optimism, arbitrum, polygon, gnosis
- Payment failure via x402 (insufficient USDC balance) results in 402 response and no data returned
- Non-existent or undeployed contract address returns zero value for all slots without error

## How this service works

Read any raw contract storage slot via eth_getStorageAt — the low-level read auditing, proxy-resolution and advanced trading agents make to inspect contract state directly. Pass address + slot. Across Base, Ethereum, Optimism, Arbitrum, Polygon, Gnosis. Free public RPC; undercuts onesource at $0.001 on 6 chains.

## Output

A JSON object containing the queried contract address, the storage slot index, the blockchain network name, and the raw 32-byte hex value stored at that slot (e.g. {"address":"0x...","slot":"0x0","chain":"ethereum","value":"0x0000...0001"}).

## 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",
     "required": [
      "address",
      "slot"
     ],
     "properties": {
      "slot": {
       "type": "string",
       "description": "Storage slot, hex or decimal"
      },
      "chain": {
       "type": "string",
       "description": "base|ethereum|optimism|arbitrum|polygon|gnosis (default base)"
      },
      "address": {
       "type": "string",
       "description": "Contract address (0x...)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "value": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-contract-storage-slot-reader-eef644c3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from store.agentexchange.work](https://www.zero.xyz/host/store.agentexchange.work/llms.txt)