# Base Storage Slot Read

> Base Storage Slot Read is a paid API for AI agents from agent-data-tools.revmesh2074.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-24).

Reads a raw 32-byte storage slot of any contract on the Base blockchain using eth_getStorageAt, returning the value as a hex string, number, and address.

## Facts

- Endpoint: GET https://agent-data-tools.revmesh2074.workers.dev/base/storage?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Provider: agent-data-tools.revmesh2074.workers.dev
- Website: https://agent-data-tools.revmesh2074.workers.dev
- Canonical page: https://www.zero.xyz/c/agent-data-tools-revmesh2074-workers-dev-base-storage-slot-read-dfb315c5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_q0PMC3_MEbHh4Bo9mfNy6

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 agent-data-tools-revmesh2074-workers-dev-base-storage-slot-read-dfb315c5
```

Example prompt: Can you read storage slot 0 of the Base contract at 0x4200000000000000000000000000000000000010 and tell me what address or number is stored there?

## When to prefer this

Use this endpoint when you need to read internal contract state on Base that has no public getter function — such as owner variables, proxy implementation pointers, or mapping entries accessed by their keccak256 slot key. Prefer the dedicated base_proxy endpoint for standard EIP-1967 proxy lookups. Choose this over Ethereum mainnet or Polygon equivalents when the contract is specifically deployed on Base (chainId 8453).

## Known failure modes

- 400 error (uncharged) if the contract address is malformed or not a valid 0x address
- 400 error (uncharged) if the slot key is not a valid decimal index or 0x 32-byte hex string
- Empty or zero value returned if the slot is uninitialized
- No error if the address is valid but holds no contract — returns zero slot value
- Network or RPC timeout returning a 5xx error

## How this service works

Read one raw storage slot of a contract on Base (eth_getStorageAt): the 32-byte word, as a number and, when it holds one, as an address. Slot is a decimal index or a 0x 32-byte key (mapping and proxy slots). Use to inspect contract state that has no getter, owners or implementation pointers; for proxies use base_proxy. A malformed address or slot is rejected with 400, uncharged.

## Output

Returns a JSON object containing: the queried slot key, the raw 32-byte hex value, the value interpreted as a large integer (asNumber), the value interpreted as an EVM address if applicable (asAddress), the block number at which the read was taken, the chain name ('base'), and the chainId (8453).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "address"
 ],
 "properties": {
  "slot": {
   "type": "string",
   "description": "Slot: a decimal index (0, 1, 2…) or a 0x 32-byte key"
  },
  "address": {
   "type": "string",
   "description": "0x contract address"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "slot": {
   "type": "string"
  },
  "block": {
   "type": "number"
  },
  "chain": {
   "type": "string"
  },
  "value": {
   "type": "string"
  },
  "address": {
   "type": "string"
  },
  "chainId": {
   "type": "number"
  },
  "asNumber": {
   "type": "string"
  },
  "asAddress": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-data-tools-revmesh2074-workers-dev-base-storage-slot-read-dfb315c5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-data-tools.revmesh2074.workers.dev](https://www.zero.xyz/host/agent-data-tools.revmesh2074.workers.dev/llms.txt)