# Sign Transaction API

## Introduction

The signTransaction method allows securely signing an Ethereum transaction within an authenticated session.

To sign a message a user  / an account would need to have to have been register and authenticated  by going through [Register using API](/authentication/passkeys/registration/register-using-api.md) flow. 

Once you have registered the user, you can choose one of the below 2 flows

## **Session-Based Authentication**

### Request Spec

Follow the [Authenticating with API](/authentication/passkeys/authentication/authenticating-with-api.md) flow to obtain the session and then do the following HTTP request

[**Headers**](broken://pages/6Ip1xrKh5rkgidowSGll)**:**

* X-Encrypted-Session: Session information for maintaining state or continuity.
* X-Encrypted-Key: Encrypted key for secure processing of the request.
* X-Encrypted-User: User details encrypted using encryption key

**Parameters:**

* `params`: The transaction parameters as a TypedTransaction object.
  * `from` - The sender address
  * `nonce` - The transaction nonce
  * `maxPriorityFeePerGas` - Max tip paid to miner
  * `maxFeePerGas` - Max total fee willing to pay
  * `to` - Recipient address
  * `gas` - Gas limit
  * `value` - Amount of ETH to send
  * `chainId` - Network ID
  * `type` - EIP-2718 transaction type

**Returns:**

An RLP encoded transaction signature that can be executed as a raw transaction

### Request Example

```http
POST / HTTP/1.1
Host: tiramisu.0xpass.io
Content-Type: application/json
X-Encrypted-Session: eJjdnfdknf...
X-Encrypted-Key: jp6t2GVOvzltN+4VGc21ZKPIbLjEvitE34cFYDvVNrcmF2ukcKMTO8R/F0wbonGZM0NZBg2X94FvirH6Hi2U1zFlXN5srkOdvQL3lVNZ86gbfEtJFPOEAeZkxtTOKOsH4ZXPtUbFOjT2Niblo8njOKibOoAMRKIhtsNTTvRXjHRxnNqVs3QcSe7XbO1DbH/pdRgq+YZN13znlSRsupu4G/h/KBEZr98wXFo8PeDV9F8ZV56F90GqQ3wKzFUBwC9rJihGz0omH+eJA0jB/K7BYt30fhWDnqaLNP2eb1mbIjBCmv6sXqu2jtghr3ejl0YwjP9lCO+aVD7bophfb/IyKg==
X-Encrypted-User: JZVjZw33OGoQDEMcbOdckx4TzspQEKP5j+iAGqf6b6gPleziY/Noyd4uW6KMSujq0HKP2Rb69p9Wi8ic5O8LZl9oTmmWk4op0CUKejqcV5DsNDp83PYzUg==
{
    "jsonrpc": "2.0",
    "method": "eth_signTransaction",
    "params": [
        {
            "from": "0x764904Df4B0e3eBabBEE902e356D9cA701e1fC70",
            "nonce": "0",
            "maxPriorityFeePerGas": "0x9184E72A", 
            "maxFeePerGas": "0x9184E72A",
            "to": "0xb89FF4E9AD6B33F69153fa710F9849f51712eEc4",
            "gas": "0x7530", 
            "value": "0x2386F26FC10000", 
            "chainId": "0x13881",
            "type": "0x02"
        }
    ],
    "id": 1
}
```

### Response Example

```json
{
    "jsonrpc": "2.0",
    "result": "0x02f8748301388180849184e72a849184e72a82753094b89ff4e9ad6b33f69153fa710f9849f51712eec4872386f26fc1000080c080a0997d192e9037357eb47ce92f62bc3eb40946952322588527cb2a8bcfee364ee2a038ca2627eb05d833fa0dd7b96ba2a3bdf09907ad95c1a7f2fc3e5d4af7779582",
    "id": "1"
}
```

## **Direct Passkey Authentication**

### Request Spec

In order to use this approach, you must sign your User Input json using Passkey to obtain a signature.

[**Headers**](broken://pages/6Ip1xrKh5rkgidowSGll)

* X-Encrypted-Key: Encrypted key for secure processing of the request.
* X-Encrypted-Webauthn-Signature: Webauthn signature encrypted using encryption key
* X-Encrypted-User: User details encrypted using encryption key

**Parameters:**

* `params`: The transaction parameters as a TypedTransaction object.
  * `from` - The sender address
  * `nonce` - The transaction nonce
  * `maxPriorityFeePerGas` - Max tip paid to miner
  * `maxFeePerGas` - Max total fee willing to pay
  * `to` - Recipient address
  * `gas` - Gas limit
  * `value` - Amount of ETH to send
  * `chainId` - Network ID
  * `type` - EIP-2718 transaction type

**Returns:**

An RLP encoded transaction signature that can be executed as a raw transaction

### Request Example

```http
POST / HTTP/1.1
Host: tiramisu.0xpass.io
Content-Type: application/json
X-Encrypted-Webauthn-Signature: eJjdnfdknf...
X-Encrypted-Key: jp6t2GVOvzltN+4VGc21ZKPIbLjEvitE34cFYDvVNrcmF2ukcKMTO8R/F0wbonGZM0NZBg2X94FvirH6Hi2U1zFlXN5srkOdvQL3lVNZ86gbfEtJFPOEAeZkxtTOKOsH4ZXPtUbFOjT2Niblo8njOKibOoAMRKIhtsNTTvRXjHRxnNqVs3QcSe7XbO1DbH/pdRgq+YZN13znlSRsupu4G/h/KBEZr98wXFo8PeDV9F8ZV56F90GqQ3wKzFUBwC9rJihGz0omH+eJA0jB/K7BYt30fhWDnqaLNP2eb1mbIjBCmv6sXqu2jtghr3ejl0YwjP9lCO+aVD7bophfb/IyKg==
X-Encrypted-User: JZVjZw33OGoQDEMcbOdckx4TzspQEKP5j+iAGqf6b6gPleziY/Noyd4uW6KMSujq0HKP2Rb69p9Wi8ic5O8LZl9oTmmWk4op0CUKejqcV5DsNDp83PYzUg==
{
    "jsonrpc": "2.0",
    "method": "eth_signTransaction",
    "params": [
        {
            "from": "0x764904Df4B0e3eBabBEE902e356D9cA701e1fC70",
            "nonce": "0",
            "maxPriorityFeePerGas": "0x9184E72A", 
            "maxFeePerGas": "0x9184E72A",
            "to": "0xb89FF4E9AD6B33F69153fa710F9849f51712eEc4",
            "gas": "0x7530", 
            "value": "0x2386F26FC10000", 
            "chainId": "0x13881",
            "type": "0x02"
        }
    ],
    "id": 1
}
```

### Response Example

```json
{
    "jsonrpc": "2.0",
    "result": "0x02f8748301388180849184e72a849184e72a82753094b89ff4e9ad6b33f69153fa710f9849f51712eec4872386f26fc1000080c080a0997d192e9037357eb47ce92f62bc3eb40946952322588527cb2a8bcfee364ee2a038ca2627eb05d833fa0dd7b96ba2a3bdf09907ad95c1a7f2fc3e5d4af7779582",
    "id": "1"
}
```


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