Delegated Signers

Register a delegated signer

Give third parties the possibility to transact with your wallet. Always maintain control over what that key can do with tight permissions and being able to revoke them at any time.

Prerequisites

• Ensure you have a wallet created.
• API Key: Ensure you have an API key with the scopes: wallets:signatures.create and wallets:transactions.create.

Adding a delegated signer

React

import { useWallet } from '@crossmint/client-sdk-react-ui';

const { wallet } = useWallet();

const externalSigner = {
    type: "external-wallet",
    address: "0x1234567890123456789012345678901234567890"
}

await wallet.addDelegatedSigner({
    signer: externalSigner,
});

Parameters

signer · string | object · required

The locator of the signer to add.

Node.js

import { CrossmintWallets, createCrossmint } from "@crossmint/wallets-sdk";

const crossmint = createCrossmint({
    apiKey: "<your-server-api-key>",
});

const crossmintWallets = CrossmintWallets.from(crossmint);

const wallet = await crossmintWallets.getWallet(
    "email:[e-mail]:evm",
    { chain: "base-sepolia", signer: { type: "email" } }
);

const externalSigner = {
    type: "external-wallet",
    address: "0x1234567890123456789012345678901234567890"
}

await wallet.addDelegatedSigner({
    signer: externalSigner,
});

Parameters

signer · string | object · required

The locator of the signer to add.

React Native

import { useWallet } from '@crossmint/client-sdk-react-native-ui';

const { wallet } = useWallet();

const externalSigner = {
    type: "external-wallet",
    address: "0x1234567890123456789012345678901234567890"
}

await wallet.addDelegatedSigner({
    signer: externalSigner,
});

Parameters

signer · string | object · required

The locator of the signer to add.

REST

Delegated signers must be approved by the wallet’s admin signer. The SDK handles this automatically, but with the REST API you must approve the transaction (if using Solana, Stellar) or signature (if using EVM) to complete it.

1. Create the delegated signer

   Call the create delegated signer endpoint.

   cURL

   curl --request POST \
       --url https://staging.crossmint.com/api/2025-06-09/wallets/email:[e-mail]:evm/signers \
       --header 'Content-Type: application/json' \
       --header 'X-API-KEY: <x-api-key>' \
       --data '{
           "chain": "base",
           "signer": "external-wallet:0x1234567890123456789012345678901234567890"
       }'
   

   See the API reference for more details.

2. Sign the approval returned in the response

   If you are using an api-key as the admin signer you can skip the following steps.

   Sign the approval message field returned in the response inside transaction.approvals (for EVM) or signature.approvals (for Solana and Stellar) using the admin signer.

3. Approve the transaction or signature to create the delegated signer

   EVM

   Call the approve signature endpoint using the signature from the previous step and the signature id returned in the call from Step 1.

   cURL

   curl --request POST \
       --url https://staging.crossmint.com/api/2025-06-09/wallets/email:[e-mail]:evm/signatures/b984491a-5785-43c0-8811-45d46fe6e520/approvals \
       --header 'Content-Type: application/json' \
       --header 'X-API-KEY: <x-api-key>' \
       --data '{
           "approvals": [{
               "signer": "email:[e-mail]",
               "signature": "0x1234567890abcdef..."
           }]
       }'
   

   See the API reference for more details.

   Solana and Stellar

   Call the approve transaction endpoint using the signature from the previous step and the transaction id returned in the call from Step 1.

   cURL

   curl --request POST \
       --url https://staging.crossmint.com/api/2025-06-09/wallets/email:[e-mail]:solana/transactions/b984491a-5785-43c0-8811-45d46fe6e520/approvals \
       --header 'Content-Type: application/json' \
       --header 'X-API-KEY: <x-api-key>' \
       --data '{
           "approvals": [{
               "signer": "email:[e-mail]",
               "signature": "5qY6wXw6zTn7..."
           }]
       }'
   

   See the API reference for more details.

Getting all delegated signers

React

import { useWallet } from '@crossmint/client-sdk-react-ui';

const { wallet } = useWallet();

const signers = await wallet.delegatedSigners();

Returns

signers · DelegatedSigner[]

The delegated signers.

Show properties

signer · string

The locator of the signer.

Node.js

import { CrossmintWallets, createCrossmint } from "@crossmint/wallets-sdk";

const crossmint = createCrossmint({
    apiKey: "<your-server-api-key>",
});

const crossmintWallets = CrossmintWallets.from(crossmint);

const wallet = await crossmintWallets.getWallet(
    "email:[e-mail]:evm",
    { chain: "base-sepolia", signer: { type: "email" } }
);

const signers = await wallet.delegatedSigners();

Returns

signers · DelegatedSigner[]

The delegated signers.

Show properties

signer · string

The locator of the signer.

React Native

React Native

import { useWallet } from '@crossmint/client-sdk-react-native-ui';

const { wallet } = useWallet();

const signers = await wallet.delegatedSigners();

Returns

signers · DelegatedSigner[]

The delegated signers.

Show properties

signer · string

The locator of the signer.

REST

cURL

curl --request GET \
    --url https://staging.crossmint.com/api/2025-06-09/wallets/email:[e-mail]:evm \
    --header 'X-API-KEY: <x-api-key>'

See the API reference for more details.