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

# Server and Client Model

The Developer SDK is deliberately split across server and client roles.

## The core flow

```mermaid theme={null}
flowchart LR
  A["Server with API key"] --> B["Prepare wallet operation"]
  B --> C["Return prepared transaction(s)"]
  C --> D["Client signs required transactions"]
  D --> E["App sends directly or sponsors submission"]
```

## What stays on the server

The server owns:

* the Swig API key
* wallet preparation calls
* optional sponsor submission
* any app-specific auth, request validation, and policy checks

The main entrypoint is:

```typescript theme={null}
import { SwigClient } from '@swig-wallet/developer-sdk/server/typescript';
```

## What reaches the client

The client should only receive prepared transaction payloads and their
signature metadata. It should not receive the API key or call the Swig backend
directly.

## Why the response is split

Prepared responses are categorized so your app knows what to do next:

| Field                         | What your app should do                          |
| ----------------------------- | ------------------------------------------------ |
| `transactions`                | submit these in order                            |
| `clientAuthorityTransactions` | get a client authority signature first           |
| `feePayerOnlyTransactions`    | send or sponsor without client authority signing |
| `operatorSignedTransactions`  | submit as-is after fee payer or sponsor handling |

For recovery-enabled wallet creation, `create(...)` also returns
`creationTransaction`, `addAuthorityTransaction`, `configureRecoveryTransaction`,
and sometimes `recoverySetup`.

## Wallet handles

The server-side wallet handle is how you move from "I know this wallet" to "I
want to prepare actions for it":

```typescript theme={null}
const wallet = swig.wallets.use({
  swigConfigAddress,
  walletAddress,
  requesterAuthority: {
    ed25519: {
      publicKey: userPublicKey,
    },
  },
});
```

If you already have an IDP session, the SDK also supports
`swig.wallets.fromIdpSession(session)`.

## The client helpers

The client package is intentionally small:

* `signPreparedTransaction(...)` for normal Ed25519 transaction signing
* `signPreparedSwigTransaction(...)` and
  `signPreparedSwigTransactions(...)` for passkey-backed Swig signature flows
* passkey signing helpers such as `createSecp256r1PasskeySigningFn(...)`

Use the browser and framework pages next if you want this split without writing
all of the proxy glue yourself.