# Token families · HyperEVM API · Femtos

> Tokens whose balance moves without Transfer logs: Aave aTokens and debt tokens, stHYPE, xStocks.

- Base URL: `https://api.femtos.xyz/v1` (REST) · `wss://api.femtos.xyz/v1/ws` (WebSocket) · MCP: `https://api.femtos.xyz/mcp`
- Auth: `Authorization: Bearer $FEMTOS_KEY` (or `X-API-KEY: $FEMTOS_KEY`). Free key: https://femtos.xyz/accounts/ (browser), or with
  no browser: `GET https://femtos.xyz/accounts/agent/challenge`, solve its proof of work, then `POST https://femtos.xyz/accounts/agent/signup`
  (https://femtos.xyz/agents.md#agent-onboarding)
- Decimals are exact strings, times Unix milliseconds, addresses lowercase `0x`
- Whole API in one file: https://femtos.xyz/agents.md · OpenAPI: https://api.femtos.xyz/v1/openapi.json · Index: https://femtos.xyz/llms.txt
- Page with live calls: https://femtos.xyz/hyperevm/token-families

## Token families — GET `/v1/token-families`

Tokens whose balance moves without Transfer logs: Aave aTokens and debt tokens, stHYPE, xStocks.

| Param | In | Example or values |
|---|---|---|
| `layer` | query | `hyperevm` |
| `family` | query | `(empty)`, `aave_atoken`, `aave_vtoken`, `sthype`, `wrapped_shares`, `backed`, `scaling_factor` |
| `includeSpam` | query | `(empty)`, `true` |

```bash
curl -H "Authorization: Bearer $FEMTOS_KEY" "https://api.femtos.xyz/v1/token-families?layer=hyperevm"
```

| Field | Type | Meaning |
|---|---|---|
| `families` | object | tokens per family |
| `tokens[]` | object | {token, family, description, symbol, decimals, params, spam, spamReason} |
| `description` | string | how balanceOf follows from the base the contract keeps |

## Related (Holders & tokens)

- [Holders](https://femtos.xyz/hyperevm/holders.md): Current balances of an ERC-20, largest first, with concentration.
- [Token registry](https://femtos.xyz/hyperevm/coins.md): HyperEVM tokens with their HyperCore spot link and price.
- [Coin detail](https://femtos.xyz/hyperevm/coin.md): One token: its links across layers, the markets it trades on, its 5 largest holders.
- [Daily token volume](https://femtos.xyz/hyperevm/volume.md): USD swap volume of a token per UTC day, both sides of every priced swap.
- [Family token holders](https://femtos.xyz/hyperevm/token-family.md): Holders of one family token with balanceOf at the indexed head.
- [Spam tokens](https://femtos.xyz/hyperevm/spam-tokens.md): Tokens the indexer flags as spam, left out of every list, and the latest flag changes.

All HyperEVM endpoints: https://femtos.xyz/hyperevm.md