6️⃣Account Creation

This step assumes you have successfully created a new customer record and verified it using Customer Creationand Customer Verification steps of the guide

Now that you have created and verified a first customer record, you are able to onboard the customer on OffBlocks accounts. To do so, you need to use /customers/{customerId}/account POST request.

Create new customer account

Creates new account for the customer and generates a challenge to be signed in order to create a related blockchain account

post

/customers/{customerId}/accounts

Authorizations

Path parameters

customerIdstring · uuidrequired

Unique customer ID

Header parameters

Signaturestringrequired

HTTP message signature

Signature-Inputstringrequired

HTTP message signature input

Idempotency-Keystring · uuidrequired

Idempotency key (UUID)

Content-Digeststringrequired

Content digest

Body

typestring · enumrequired

Type of the account

Options: card_account

currenciesstring[]required

Responses

application/json

cURL

JavaScript

Python

HTTP

cURL

curl -L \
  --request POST \
  --url 'https://api.offblocks.xyz/v1/customers/{customerId}/accounts' \
  --header 'Authorization: Bearer JWT' \
  --header 'Signature: text' \
  --header 'Signature-Input: text' \
  --header 'Idempotency-Key: 123e4567-e89b-12d3-a456-426614174000' \
  --header 'Content-Digest: text' \
  --header 'Content-Type: application/json' \
  --data '{
    "type": "card_account",
    "currencies": [
      "text"
    ]
  }'

201

400

401

404

500

201

{
  "id": "123e4567-e89b-12d3-a456-426614174000",
  "customerId": "123e4567-e89b-12d3-a456-426614174000",
  "chainId": "eip155:1:0xab16a96D359eC26a11e2C2b3d8f8B8942d5Bfcdb",
  "status": "initiating",
  "type": "card_account",
  "createdAt": "2025-02-28T01:40:25.527Z",
  "updatedAt": "2025-02-28T01:40:25.527Z",
  "currencies": [
    "text"
  ],
  "challenge": "LS0tLS1CRUdJTiBQVUJMSUMgS0VZLS0tLS0KTUZZd0VBWUhLb1pJemowQ0FRWUZLNEVFQUFvRFFnQUUzTEw1RldmVFgvL3BJaXNEL0xneFVIT2lxdlFTSUVWTgpGekloOTdLZXBlWk1iZVZsUGd1akZ4Yk5MN2x1ZVhRQnBpUWUzNmZLN0xSbXZNNHdEaWZFTkE9PQotLS0tLUVORCBQVUJMSUMgS0VZLS0tLS0="
}

Successful operation

Let's say we want to open a new card account (the only option for the time being) that's using Euro as a base currency (we don't support multi-currency accounts just yet):

{
  "type": "CARD_ACCOUNT",
  "currencies": [
    "EUR"
  ]
}

If everything was successful, you will receive a response with status 201 (Created) which looks similar to the following:

{
    "challenge": "NWRmMzU5ZjAtZDI5OS00MGExLTgwMjMtMTdjNzdhNTAxNDRj",
    "createdAt": "2024-01-12T15:07:17.358440283Z",
    "currencies": [
        "EUR"
    ],
    "customerId": "04c5851c-4386-5bd9-9f89-08312f8aee3a",
    "id": "ae61c362-4136-49af-8e01-544457fe265b",
    "status": "initiating",
    "type": "card_account",
    "updatedAt": "2024-01-12T15:07:17.358440283Z"
}

If everything went well, you will receive an account challenge to sign as a base64 encoded string. This is required to proceed to deployment stage. Signatures are not currently verified in our Sandbox environment, however they are still required to be submitted.

In order to submit a signed challenge, use a POST request to /accounts/{accountId}/challenge/sign endpoint.

Sign previously issued account challenge

Signs previously issued challenge to sign account creation or deletion transaction on-chain

post

/accounts/{accountId}/challenge/sign

Authorizations

Path parameters

accountIdstring · uuidrequired

Unique account ID

Header parameters

Signaturestringrequired

HTTP message signature

Signature-Inputstringrequired

HTTP message signature input

Idempotency-Keystring · uuidrequired

Idempotency key (UUID)

Content-Digeststringrequired

Content digest

Body

ownerIdstringrequired

Unique signer account ID in a form of a valid on-chain address

challengestring · byterequired

Original base64 encoded challenge provided by this API for owner to sign

signaturestring · byterequired

Base64 encoded signature

Responses

cURL

JavaScript

Python

HTTP

cURL

curl -L \
  --request POST \
  --url 'https://api.offblocks.xyz/v1/accounts/{accountId}/challenge/sign' \
  --header 'Authorization: Bearer JWT' \
  --header 'Signature: text' \
  --header 'Signature-Input: text' \
  --header 'Idempotency-Key: 123e4567-e89b-12d3-a456-426614174000' \
  --header 'Content-Digest: text' \
  --header 'Content-Type: application/json' \
  --data '{
    "ownerId": "eip155:1:0xab16a96D359eC26a11e2C2b3d8f8B8942d5Bfcdb",
    "challenge": "LS0tLS1CRUdJTiBQVUJMSUMgS0VZLS0tLS0KTUZZd0VBWUhLb1pJemowQ0FRWUZLNEVFQUFvRFFnQUUzTEw1RldmVFgvL3BJaXNEL0xneFVIT2lxdlFTSUVWTgpGekloOTdLZXBlWk1iZVZsUGd1akZ4Yk5MN2x1ZVhRQnBpUWUzNmZLN0xSbXZNNHdEaWZFTkE9PQotLS0tLUVORCBQVUJMSUMgS0VZLS0tLS0=",
    "signature": "IfvwaW1eCqLvQaK0/7YjvK8HBGHWHPclHHQWH4L+w6Q3CFS8CjSzq0h8G8AhzTGMc0xRrik3TyvrDm8t1JtL9Bw="
  }'

204

400

401

404

409

500

204

No body

Successful operation

{
  "ownerId": "eip155:280:0x43158f45b5EbD7b1179130131DF00393928C2691",
  "challenge": "NWRmMzU5ZjAtZDI5OS00MGExLTgwMjMtMTdjNzdhNTAxNDRj",
  "signature": "c2lnbmF0dXJl"
}

Please, not that the signature also must be a base64 encoded string. If signature is verified, you will receive an empty response with status code 204 (No Content).

If, for any reason, the original challenge is lost or cannot be signed immediately, you can fetch it again using a dedicated endpoint. If we encounter an error during signature validation via /sign endpoint, a new challenge will be issued for you to retrieve.

Retrieve account challenge

Retrieves challenge to sign account creation or deletion transaction on-chain. This operation invalidates any previously issued challenges for the account

get

/accounts/{accountId}/challenge

Authorizations

Path parameters

accountIdstring · uuidrequired

Unique account ID

Header parameters

Signaturestringrequired

HTTP message signature

Signature-Inputstringrequired

HTTP message signature input

Responses

application/json

cURL

JavaScript

Python

HTTP

cURL

curl -L \
  --url 'https://api.offblocks.xyz/v1/accounts/{accountId}/challenge' \
  --header 'Authorization: Bearer JWT' \
  --header 'Signature: text' \
  --header 'Signature-Input: text'

200

400

401

404

500

200

{
  "challenge": "LS0tLS1CRUdJTiBQVUJMSUMgS0VZLS0tLS0KTUZZd0VBWUhLb1pJemowQ0FRWUZLNEVFQUFvRFFnQUUzTEw1RldmVFgvL3BJaXNEL0xneFVIT2lxdlFTSUVWTgpGekloOTdLZXBlWk1iZVZsUGd1akZ4Yk5MN2x1ZVhRQnBpUWUzNmZLN0xSbXZNNHdEaWZFTkE9PQotLS0tLUVORCBQVUJMSUMgS0VZLS0tLS0="
}

Successful operation

Once the challenge has been successfully signed, we will proceed to deployment stage. The account will be automatically deployed and activated, which you can verify by making a GET request to /accounts/{accountId}.

Retrieve account

Retrieves account's details

get

/accounts/{accountId}

Authorizations

Path parameters

accountIdstring · uuidrequired

Unique account ID

Header parameters

Signaturestringrequired

HTTP message signature

Signature-Inputstringrequired

HTTP message signature input

Responses

application/json

cURL

JavaScript

Python

HTTP

cURL

curl -L \
  --url 'https://api.offblocks.xyz/v1/accounts/{accountId}' \
  --header 'Authorization: Bearer JWT' \
  --header 'Signature: text' \
  --header 'Signature-Input: text'

200

400

401

404

500

200

{
  "id": "123e4567-e89b-12d3-a456-426614174000",
  "customerId": "123e4567-e89b-12d3-a456-426614174000",
  "chainId": "eip155:1:0xab16a96D359eC26a11e2C2b3d8f8B8942d5Bfcdb",
  "status": "initiating",
  "type": "card_account",
  "createdAt": "2025-02-28T01:40:25.527Z",
  "updatedAt": "2025-02-28T01:40:25.527Z",
  "currencies": [
    "text"
  ]
}

Successful operation

{
    "chainId": "eip155:280:0x18102C007e4B4FBED74105E8D1e4FF4545Dbed8f",
    "createdAt": "2024-01-12T15:07:17.35844Z",
    "currencies": [
        "EUR"
    ],
    "customerId": "04c5851c-4386-5bd9-9f89-08312f8aee3a",
    "id": "ae61c362-4136-49af-8e01-544457fe265b",
    "status": "active",
    "type": "card_account",
    "updatedAt": "2024-01-12T15:09:31.118452Z"
}

From there we can proceed to issuing cards for the account.