> For the complete documentation index, see [llms.txt](https://docs.hyperlink.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hyperlink.xyz/api/setup.md).

# API Quickstart

HyperLink mirrors Hyperliquid's `/exchange` action format and EIP-712 signing, so point an existing Hyperliquid trading client at the HyperLink base URL. HyperLink is a prime broker for Hyperliquid.

## Three steps

1. Point your client at the [base URL](#base-url).
2. Create an agent wallet (your API key) in the web app or with `approveAgent`. See [Authentication & Keys](/api/api-keys.md).
3. Sign each request with EIP-712 and POST it to `/exchange`.

There are no bearer tokens or API secrets. Authentication is the signature on each request.

## Base URL

The HyperLink API base URL is `https://api.hyperlink.xyz`. WebSocket connects at `wss://api.hyperlink.xyz/ws`.

{% hint style="info" %}
The network chainId (999) is the HyperEVM network ID, used for direct on-chain contract calls such as staking. It is **not** the chainId used in EIP-712 signatures. See [Authentication & Keys](/api/api-keys.md).
{% endhint %}

## Endpoints

| Method | Path        | Purpose                                                                                    |
| ------ | ----------- | ------------------------------------------------------------------------------------------ |
| `POST` | `/exchange` | Trading actions **and** read queries. There is no separate `/info` host.                   |
| `GET`  | `/ws`       | WebSocket subscriptions and signed `post` actions. See [WebSocket API](/api/websocket.md). |

## Request envelope

Every action and query POSTed to `/exchange` uses this envelope:

```json
{
  "action": { "type": "...", "...": "..." },
  "signature": { "r": "0x...", "s": "0x...", "v": 27 },
  "nonce": 1748438400000,
  "expiresAfter": 1748438460000,
  "vaultAddress": "0x0000000000000000000000000000000000000000"
}
```

| Field          | Required | Notes                                                   |
| -------------- | -------- | ------------------------------------------------------- |
| `action`       | Yes      | The action or query object; `type` selects the variant. |
| `signature`    | Yes      | EIP-712 signature with `r`, `s`, `v`.                   |
| `nonce`        | Yes      | Unix time in **milliseconds**, single-use per signer.   |
| `expiresAfter` | No       | Millisecond timestamp; must be `>=` `nonce`.            |
| `vaultAddress` | No       | Act on behalf of a vault or sub-account.                |

Write actions return `{ "status": "ok" | "err", "response": { ... } }`; read queries return raw JSON.

## First request

Use a Hyperliquid SDK pointed at the HyperLink base URL. It handles EIP-712 signing and the order envelope for you.

```python
import os
from eth_account import Account
from hyperliquid.exchange import Exchange
from hyperliquid.utils.types import Cloid

# Your API key is the agent private key. Keep it in an env var, never hardcode.
agent = Account.from_key(os.environ["AGENT_PRIVATE_KEY"])

# Point the client at the HyperLink base URL.
exchange = Exchange(agent, base_url="https://api.hyperlink.xyz")

# Place a resting limit buy: 0.1 BTC at 50000, good-til-cancel.
result = exchange.order(
    name="BTC",
    is_buy=True,
    sz=0.1,
    limit_px=50000,
    order_type={"limit": {"tif": "Gtc"}},
    cloid=Cloid.from_str("0x1234567890abcdef1234567890abcdef"),  # HyperLink requires a cloid
)
print(result)
```

{% hint style="info" %}
HyperLink **requires** a client order id (`cloid`) on every order. Pass it via your SDK's `cloid` parameter, or the `c` field in a raw request.
{% endhint %}

For TypeScript, use [nktkas/hyperliquid](https://github.com/nktkas/hyperliquid) with the same base URL.

## Coming from Hyperliquid?

| Stays the same                                   | Changes                                                         |
| ------------------------------------------------ | --------------------------------------------------------------- |
| Order structures, EIP-712 signing, asset indexes | Base URL points to HyperLink                                    |
| Hyperliquid trading SDKs and tooling             | Balances are private; deposits and withdrawals are on HyperCore |

Private read queries use signed `POST /exchange` requests. There is no separate HyperLink `/info` host.

## Next steps

* [Authentication & Keys](/api/api-keys.md): create agent keys and sign requests.
* [Exchange Methods](/api/exchange-methods.md): actions, queries, and schemas.
* [WebSocket API](/api/websocket.md): real-time subscriptions.


---

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