# ERC-20 Total Supply Lookup (Ethereum Mainnet)

> ERC-20 Total Supply Lookup (Ethereum Mainnet) is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-27).

Returns the raw and human-readable totalSupply of any ERC-20 token contract on Ethereum mainnet via a read-only eth_call.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/eth-total-supply?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc-20-total-supply-lookup-ethereum-mainnet-0c16eee5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xHmUJcPxmVntWT1RS95RB

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 erc-20-total-supply-lookup-ethereum-mainnet-0c16eee5 -d '<json body>'
```

Example prompt: What is the total supply of USDC on Ethereum mainnet? The contract address is 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 — give me both the raw number and the human-readable amount.

## When to prefer this

Choose this endpoint when you need a fast, read-only on-chain totalSupply lookup for a single ERC-20 token on Ethereum mainnet and want both raw and decimal-adjusted values in one call. Prefer it over general RPC providers when you want a simple REST interface without managing JSON-RPC directly, and over block explorer APIs when you need guaranteed freshness via direct eth_call rather than indexed data.

## Known failure modes

- Invalid or non-ERC-20 contract address returns an error or empty result
- Contract does not implement decimals() — raw supply is returned but human-readable value may be absent
- Non-mainnet addresses (e.g. testnets or L2s) will not resolve correctly
- Malformed address format (not a valid checksummed Ethereum address) returns a validation error
- Payment failure on Base for the $0.001 USDC fee blocks the request

## How this service works

Call when an agent needs ERC-20 totalSupply for one Ethereum mainnet token, raw and human when decimals() is readable. Send token. Read-only eth_call on eip155:1. No spend. Send JSON {"token":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"}. Exact $0.001 USDC on Base. Try unpaid POST /v1/sandbox/eth-total-supply first.

## Output

Returns a JSON object containing total_supply_raw (the integer value directly from the contract's totalSupply() call) and total_supply (the human-readable value scaled by decimals() if that function is readable on the contract).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string",
   "examples": [
    "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
   ],
   "description": "ERC-20 contract on Ethereum mainnet. Example: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48. Returns total_supply_raw and a human total_supply when decimals() is readable. Read-only."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erc-20-total-supply-lookup-ethereum-mainnet-0c16eee5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)