# Ethereum ERC-20 Total Supply

> Ethereum ERC-20 Total Supply is a paid API for AI agents from api.arysphere.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-17).

Returns the total supply (uint256) of a given ERC-20 token contract on Ethereum mainnet via the totalSupply() call.

## Facts

- Endpoint: GET https://api.arysphere.com/v1/ventures/x402_eth_reads_v1/eth_mainnet_erc20_totalsupply?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ethereum-erc-20-total-supply-574722f7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VxhKLnA4tPrjZUqpxfZOZ

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 ethereum-erc-20-total-supply-574722f7
```

Example prompt: What is the total supply of the ERC-20 token at contract address 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum mainnet?

## When to prefer this

Use this endpoint when you need to read the on-chain ERC-20 totalSupply for a specific token contract on Ethereum mainnet. Prefer this over general-purpose blockchain explorers when you need a lightweight, paid, agent-callable API that returns raw uint256 supply data. It is ideal for DeFi analytics, token monitoring, and market cap calculations where only a contract address is needed.

## Known failure modes

- Invalid or malformed token address (not matching 0x + 40 hex pattern) returns an error response with ok: false
- Contract address is not an ERC-20 token (no totalSupply function) results in a revert or error
- Network timeout or RPC node unavailability may cause a failed response
- Calling with an EOA (externally owned account) address instead of a contract address returns an error
- Missing or malformed query parameter returns a validation error

## How this service works

ARYSPHERE sells AI-written verdicts on Base token contracts (a grade, a one-liner, a roast and the contract's facts) and Base/Ethereum chain reads, paid per call in USDC on Base over x402 v2. No account and no API key.

## Output

Returns a JSON object with: `ok` (boolean success flag), `result` (the ERC-20 totalSupply as a decimal uint256 string), `chain` (chain identifier), `service` (endpoint identifier), and `method` (HTTP method used). On failure, includes an `error` field describing the issue.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "token": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "ERC-20 contract, 0x + 40 hex"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "chain": "ethereum",
  "method": "totalSupply",
  "result": "88302633055702652",
  "service": "x402_eth_reads_v1.eth_mainnet_erc20_totalsupply"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ethereum-erc-20-total-supply-574722f7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.arysphere.com](https://www.zero.xyz/host/api.arysphere.com/llms.txt)