# fastapi.online — Token Supply Lookup

> fastapi.online — Token Supply Lookup is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-19).

Returns the total token supply for a given contract address on a specified EVM-compatible blockchain network

## Facts

- Endpoint: POST https://api.fastapi.online/token-supply?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastapi-online-token-supply-lookup-4dd6c8a1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KbiDZGT7yeKs-OdyaDC6x

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 fastapi-online-token-supply-lookup-4dd6c8a1 -d '<json body>'
```

Example prompt: What is the total token supply for the contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum?

## When to prefer this

Use this endpoint when you need a quick, pay-per-call lookup of a token's total supply on a specific EVM chain without setting up your own RPC infrastructure. It supports Ethereum, Base, Polygon, Arbitrum, and Optimism. Prefer this over self-managing RPC calls when you want a simple HTTP API abstraction priced at $0.001 USDC with no signup required.

## Known failure modes

- Invalid or non-existent contract address returns an error or zero
- Unsupported chain value outside the allowed enum returns a validation error
- Contract address not corresponding to a token contract may return zero or an unexpected result
- Network timeouts or RPC node issues may cause delayed or failed responses

## How this service works

Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&amp;A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding &amp; crypto utilities, date/time calculators, geo/coordinate math, math &amp; finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.

## Output

Returns the total token supply associated with the given contract address on the specified EVM-compatible chain (ethereum, base, polygon, arbitrum, or optimism), typically as a numeric value representing the on-chain supply figure.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "enum": [
    "ethereum",
    "base",
    "polygon",
    "arbitrum",
    "optimism"
   ],
   "type": "string"
  },
  "address": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-token-supply-lookup-4dd6c8a1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)