> ## Documentation Index
> Fetch the complete documentation index at: https://docs.turnkey.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Advanced API requests

> Use the Turnkey Swift SDK to sign raw payloads and configure custom Stampers for advanced request flows.

## Overview

This guide shows how to:

* Sign a raw payload and read the resulting signature
* Access the `activity` returned by the API
* Use custom Stampers (e.g., passkey) with `TurnkeyClient`

## The HTTP client

To make advanced API requests, use the `TurnkeyClient` exposed by `TurnkeyContext`.\
This client is tied to the active session, so stamping and organization context are automatically handled for you.

You can see the [API Reference](/api-reference/overview) for a complete list of available API endpoints and their parameters. All of these can be accessed through the `TurnkeyClient`.

## Sign a raw payload

Use `signRawPayload` with a `TSignRawPayloadBody`. The response includes the `activity` and the ECDSA signature components `r`, `s`, and `v`. Below, we call it using the session‑bound client from `TurnkeyContext` (no extra configuration needed).

```swift theme={"system"}
import TurnkeyHttp
import TurnkeyTypes
import TurnkeySwift

guard let client = TurnkeyContext.shared.client else {
  // Not authenticated; initialize auth first
  throw NSError(domain: "Turnkey", code: -1)
}

// Example message in hex to match HEXADECIMAL encoding
let message = "Hello, Turnkey!"
let payload = Data(message.utf8).map { String(format: "%02x", $0) }.joined()

let body = TSignRawPayloadBody(
  organizationId: TurnkeyContext.shared.session?.organizationId,
  encoding: .payload_encoding_hexadecimal,
  hashFunction: .hash_function_not_applicable,
  payload: payload,
  signWith: "<wallet_account_or_key_id>"
)

let resp = try await client.signRawPayload(body)
// Signature parts
let r = resp.r
let s = resp.s
let v = resp.v
```

### Access the activity

When creating, modifying, or using resources within Turnkey, an activity is created. You can learn more about activities in the [Activities](/api-reference/activities/overview) section.

If you use the `TurnkeyClient`, you can view all the metadata of the activity you are performing. This includes the activity ID, votes list, status, and more.

```swift theme={"system"}
let activity = resp.activity
print("Activity ID:", activity.id)
print("Status:", activity.status.rawValue)
print("Type:", activity.type.rawValue)
```

## Using other stampers: Passkey

By default, the session-bound `TurnkeyClient` handles stamping for you.\
If you want to stamp a request using a passkey explicitly, instantiate a passkey `Stamper`, create a `TurnkeyClient` with it, and sign a payload:

```swift theme={"system"}
import AuthenticationServices
import TurnkeyHttp
import TurnkeyTypes
import TurnkeyStamper

let anchor: ASPresentationAnchor = /* your UI window */
let stamper = Stamper(
  rpId: "yourdomain.com",
  presentationAnchor: anchor
)

let client = TurnkeyClient(
  stamper: stamper
)

let message = "Hello, Turnkey!"
let payload = Data(message.utf8).map { String(format: "%02x", $0) }.joined()
let resp = try await client.signRawPayload(TSignRawPayloadBody(
  organizationId: "<your_organization_id>",
  encoding: .payload_encoding_hexadecimal,
  hashFunction: .hash_function_not_applicable,
  payload: payload,
  signWith: "<wallet_account_or_key_id>"
))
let (r, s, v) = (resp.r, resp.s, resp.v)
```

With a configured `TurnkeyClient`, you can call any signing or activity endpoint (e.g., `signRawPayload`, `signTransaction`) and the client will handle stamping under the hood using your chosen stamper.

<Note>
  When using the passkey stamper, the user will be prompted to sign using the
  passkey before every request is made.
</Note>