zkLogin wallet API

User-controlled wallets to make Web3 unseen

Overview

zkLogin is a Sui primitive that allows users to transact on Sui using the OAuth login flows they're familiar with, eliminating the friction of handling cryptographic keys or remembering mnemonics. zkLogin can be thought of as a two-factor authentication scheme, since sending a transaction requires both a credential from a recent OAuth login and a salt managed by someone other than the OAuth provider (in this case, Shinami). To learn more, see the Sui Foundation's zkLogin doc.

We've also created a tutorial that helps you very quickly create your first zkLogin app that interacts with Shinami Gas Station for transaction sponsorship.

Use Cases

When you want to offer your users a non-custodial wallet that doesn't require them to remember mnemonics and pass-phrases - only their OAuth provider password.

Authentication, Rate Limits, and Error Handling

Authentication

See our Authentication and API Keys guide.

🚧

Security Warning: Do not call this API from your frontend.

We strongly recommend having your backend server integrate with Shinami's zkLogin wallet API to prevent exposing any access keys on the frontend. Exposed information could lead to a malicious actor signing transactions on behalf of your users.

Error Handling

See our Error Reference for guidance on the errors you may receive from our services, including a section on errors specific to the zkLogin wallet API.

zkLogin Addresses

A zkLogin wallet address is derived from iss, aud, sub, salt in the OpenID connect response, where:

  • iss: The OpenID provider.
  • aud : The unique identifier assigned to your application by the OpenID provider.
  • sub: The OpenID provider's locally unique and never reassigned identifier for the user.
  • salt: A consistent, ideally unique, value used to unlink the OpenID identifier with the on-chain address.

As a result, a user will have a new zkLogin wallet address if any of the above values change. For example, if one of your users logs in via Google and then Twitch - or with one Google email and then another - and you use both credentials with zkLogin, each credential will be linked to a different address. To learn more, see the Sui Foundation's zkLogin doc.


zkLogin wallet service methods

shinami_zkw_getOrCreateZkLoginWallet

Description
Retrieves a zkLogin wallet along with its associated salt, creating a new wallet if necessary. This method provides the option to create and use multiple zkLogin wallets per (user, OAuth provider) pair by using the optional subWallet parameter. Note that your users will already have a different zkLogin wallet for each OAuth provider they use, whose jwt you pass to this method (see zkLogin Addresses for more details).

The example below uses the Shinami Clients SDK.

Request Parameters

NameTypeDescription
jwtStringA valid JWT signed by one of the supported OpenID providers. The JWT nonce must be prepared according to the zkLogin requirements.
keyClaimNameStringOptional. The claim name in the JWT that identifies a particular user. Defaults to "sub". Currently, Mysten's zkLogin implementation only supports the "sub" field of the OpenID spec. This parameter allows for forward compatibility as the implementation expands to support other values.
subWalletIntegerOptional. The sub-wallet id, which enables the same OpenID user to have more than one wallet addresses. Defaults to 0

Example Request Template

Replace all instances of {{name}} with the actual value for that name

 curl https://api.shinami.com/zkwallet/v1 \
 -X POST \
 -H 'X-API-Key: {{walletAccessKey}}' \
 -H 'Content-Type: application/json' \
 -d '{
         "jsonrpc":"2.0", 
         "method":"shinami_zkw_getOrCreateZkLoginWallet", 
         "params":[
             "{{signedJWTToken}}"
         ], 
         "id":1
      }'
import { ZkWalletClient } from "@shinami/clients";

// Obtain wallet access key from your Shinami web portal.
const zkw = new ZkWalletClient({{walletAccessKey}});

// Prepare a nonce according to the zkLogin requirements.
// Obtain a valid jwt with that nonce from a supported OpenID provider.

// Get zkLogin wallet salt.
await zkw.getOrCreateZkLoginWallet({{jwt}});

Example Response

{
    "jsonrpc": "2.0",
    "result": {
        "userId": {
            "iss": "https://id.twitch.tv/oauth2",
            "aud": "2bc0920c90ufn0adomxlca3pldbdpo",
            "keyClaimName": "sub",
            "keyClaimValue": "984333370"
        },
        "subWallet": 0,
        "salt": "kL+fRWN8888cKl5D72qzCQ==",
        "address": "0x6a7b07da9d2c210bbbe044dbe29f0c5ae20444584a4d8ee9a804839f8256ea3c"
    },
    "id": 1
}
{
    userId: {
        iss: 'https://id.twitch.tv/oauth2',
        aud: '2bc0920c90ufn0adomxlca3pldbdpo',
        keyClaimName: 'sub',
        keyClaimValue: '984333370'
    },
    subWallet: 0,
    salt: 192403790493605555550623021243959522057n,
    address: '0x6a7b07da9d2c210bbbe044dbe29f0c5ae20444584a4d8ee9a804839f8256ea3c'
}

Response Data

NameTypeDescription
userIdObjectThe OAuth user information used to create the wallet.
subWalletIntegerThe subWallet number.
saltcURL: Base64 encoded String SDK: BigIntThe salt associated with this zkLogin wallet.
addressHex encoded StringThe Sui zkLogin address of this wallet.

zkProver service methods

shinami_zkp_createZkLoginProof

Description
Generate a zkLogin proof prior to signing and executing a transaction. The example below uses the Shinami Clients SDK.

Note: Devnet has a different zkey than Testnet and Mainnet. Shinami's zk prover currently only works with Testnet and Mainnet.

Request Parameters

NameTypeDescription
jwtStringA valid JWT signed by one of the supported OpenID providers. The JWT nonce must be prepared according to the zkLogin requirements.
maxEpochcURL: String SDK: IntThe max epoch used to prepare the JWT nonce. This governs the expiration of the zkLogin proof. Once it expires, you will have to ask the user to sign in again. One epoch is roughly one day. See the expiration of recent epochs in a Sui explorer like Suivision or Suiscan (note that Mainnet and Testnet are not on the same epoch).
extendedEphemeralPublicKeycURL: Base64 encoded String SDK: PublicKeyThe ephemeral public key used to prepare the JWT nonce. Must be prepended with the scheme flag and encoded in Base64 (see example here). The corresponding private key must be used to sign any transactions to be executed with this proof.
jwtRandomnesscURL: Base64 encoded String SDK: BigIntThe random bytes used to prepare the JWT nonce (see example here).
saltcURL: Base64 encoded String SDK: BigIntThe zkLogin wallet salt. Together with the provided JWT, this determines the zkLogin on-chain address.
keyClaimNameStringOptional. The claim name in the JWT that identifies a particular user. Defaults to "sub". Currently, Mysten's zkLogin implementation only supports the sub field of the OpenID spec. This parameter allows for forward compatibility as the implementation expands to support other values.

Example Request Template

Replace all instances of {{name}} with the actual value for that name

curl https://api.shinami.com/zkprover/v1 \
-X POST \
-H 'X-API-Key: {{walletAccessKey}}' \
-H 'Content-Type: application/json' \
-d '{
        "jsonrpc":"2.0", 
        "method":"shinami_zkp_createZkLoginProof", 
        "params":[
            "{{jwt}}",
            "{{maxEpoch}}",
            "{{extendedEphemeralPublicKey}}",
            "{{jwtRandomness}}",
            "{{salt}}"
        ], 
        "id":1
    }'
import { ZkProverClient } from "@shinami/clients";

// Obtain wallet access key from your Shinami web portal.
const zkp = new ZkProverClient({{walletAccessKey}});

// Create a zkProof.
await zkp.createZkLoginProof(
    {{jwt}},
    {{maxEpoch}},
    {{ephemeralPublicKey}},
    {{jwtRandomness}},
    {{salt}}
);

// Now you can sign transaction blocks with ephemeralPrivateKey, and assemble the zkLogin signature
// using zkProof.

Example Response

{
    "jsonrpc": "2.0",
    "result": {
        "zkProof": {
            "proofPoints": {
                "a": ["15523188928150068463877187176143113666714843703470604151076285692983325640642", "5937622317780822197753258881898720685630444182643789312895382585679701582730", "1"],
                "b": [
                    ["16826302723856343423452057269835204629749355045593813315170205467027472681113", "13797818130832460450334887874511731864855590610477696974834238052347712422314"],
                    ["13373917712679082794928414217966585760669198351828608413595476883128268622714", "5700527829855762859349841977943997112007134227264278415875624634861579977183"],
                    ["1", "0"]
                ],
                "c": ["7520248514700601656024563691610669758825183429353083260336955084416144661718", "20552359067831153630006195193902483617859079319246848227965146473634030062290", "1"]
            },
            "issBase64Details": {
                "value": "wiaXNzIjoiaHR0cHM6Ly9pZC50d2l0Y2gudHYvb2F1dGgyIiw",
                "indexMod4": 2
            },
            "headerBase64": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6IjEifQ"
        }
    },
    "id": 1
}
{
    proofPoints: {
        a: [
            '10210145730043037811940974600447596138332245137712632111543948579663620583434',
            '7161160787659733995589070724990899004457677439433421417304252171408748983773',
            '1'
        ],
        b: [ [Array], [Array], [Array] ],
        c: [
            '14336916288409630215040261300089886420211729238372809076105326107110995622366',
            '16791539167604801843541798961147781044566621780138018818605704529730677460898',
            '1'
        ]
    },
    issBase64Details: {
        value: 'wiaXNzIjoiaHR0cHM6Ly9pZC50d2l0Y2gudHYvb2F1dGgyIiw',
        indexMod4: 2
    },
    headerBase64: 'eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6IjEifQ'
}

Response Data

TypeDescription
JSON objectThe zkLogin proof for the given JWT.