# Create public key

Register an extended public key for HD address derivation.

Endpoint: POST /public_keys
Version: 0.23.9
Security: Auth

## Request fields (application/json):

  - `derivation_path` (string, required)
    HD derivation path in BIP-44 format. Supports both account-level (m/purpose'/coin_type'/account')
and change-level (m/purpose'/coin_type'/account'/change) paths.

Account-level paths (depth-3) represent HD wallet accounts and cannot derive addresses directly —
use the children endpoint to create change-level child keys first.

  - `label` (string, required)
    User-friendly label for the public key.

  - `value` (string, required)
    BIP32/SLIP-0132 extended public key in Base58Check format.

## Response 200 fields (application/json):

  - `item` (object, required)
    HD public key used to derive child addresses.

  - `item.id` (string, required)
    Unique identifier (UUID v4).

  - `item.value` (string, required)
    BIP32/SLIP-0132 extended public key in Base58Check format.

  - `item.label` (string, required)
    User-friendly label for the public key.

  - `item.derivation_path` (string, required)
    HD derivation path in BIP-44 format. Supports both account-level (m/purpose'/coin_type'/account')
and change-level (m/purpose'/coin_type'/account'/change) paths.

Account-level paths (depth-3) represent HD wallet accounts and cannot derive addresses directly —
use the children endpoint to create change-level child keys first.

  - `item.children` (array)
    Child keys derived from this account-level key. Present only for account-level keys (depth-3).
Each child represents an external (change=0) or internal (change=1) chain.
    Example: [{"id":"550e8400-e29b-41d4-a716-446655440000","value":"xpub6EFxzN6ZgMCZ1PxeRigmAhm2UBGzXtZNgznCEaWuEt9efBpJwAXFA4ZckBdR1pdMQ1pBgsey7ebjToZ5gYXveftB3zwoQ8NvEkimvyaz34i","label":"Main Bitcoin Wallet","derivation_path":"m/84'/0'/0'","children":[{"id":"660e8400-e29b-41d4-a716-446655440001","value":"xpub6F7C1ZtQ411zykk6KTEoQMqfNdxiSA4uxAwAoqFanijnAavqQvVmh5zZCH6Swhdbzt2HuMRLx4chEVRZu9ic4Cnkkq5AsQcmjeMASk6FLqf","label":"external","derivation_path":"m/84'/0'/0'/0","created_at":"2025-01-15T12:00:00Z","updated_at":"2025-01-15T12:00:00Z"}],"created_at":"2025-01-15T12:00:00Z","updated_at":"2025-01-15T12:00:00Z"}]

  - `item.created_at` (string, required)
    Timestamp when the resource was created.

  - `item.updated_at` (string, required)
    Timestamp when the resource was last updated.

## Response 400 fields (application/problem+json):

  - `type` (string, required)
    A URI that identifies the error type.
Open it in a browser to read about this category of error.
    Example: "https://docs.vilna.io/apis/problems/invalid-request"

  - `title` (string, required)
    A short summary of the error type.
Use detail for information specific to this occurrence.
    Example: "Invalid Request"

  - `status` (integer, required)
    The HTTP status code for this error.
Matches the status code of the HTTP response.
    Example: 400

  - `detail` (string)
    A human-readable explanation of what went wrong in this specific case.
May be localized.
    Example: "Validation error"

  - `instance` (string)
    A URI that identifies this specific error occurrence.
Include this value when contacting support.

  - `code` (string, required)
    Stable machine-readable error code ({domain}.{reason}) for programmatic error handling. Unlike the HTTP status or free-form detail, this code is guaranteed not to change between versions for a given error condition, so it is safe to branch on in client code. Defaults to unspecified when the server has not assigned a specific code.
    Example: "blockchain.name_too_long"

  - `fields` (array)
    List of invalid fields in the request

  - `fields.name` (string, required)
    The name of the invalid field
    Example: "meta"

  - `fields.reason` (string, required)
    Why this field is invalid
    Example: "Exceeded maximum data size — must not exceed 1000 characters"

## Response 401 fields (application/problem+json):

  - `type` (string, required)
    A URI that identifies the error type.
Open it in a browser to read about this category of error.
    Example: "https://docs.vilna.io/apis/problems/unauthorized"

  - `title` (string, required)
    A short summary of the error type.
Use detail for information specific to this occurrence.
    Example: "Unauthorized"

  - `status` (integer, required)
    The HTTP status code for this error.
Matches the status code of the HTTP response.
    Example: 401

  - `detail` (string)
    A human-readable explanation of what went wrong in this specific case.
May be localized.
    Example: "Missing or invalid authentication credentials"

  - `instance` (string)
    A URI that identifies this specific error occurrence.
Include this value when contacting support.

  - `code` (string, required)
    Stable machine-readable error code ({domain}.{reason}) for programmatic error handling. Unlike the HTTP status or free-form detail, this code is guaranteed not to change between versions for a given error condition, so it is safe to branch on in client code. Defaults to unspecified when the server has not assigned a specific code.
    Example: "auth.unauthorized"

## Response 403 fields (application/problem+json):

  - `type` (string, required)
    A URI that identifies the error type.
Open it in a browser to read about this category of error.
    Example: "https://docs.vilna.io/apis/problems/forbidden"

  - `title` (string, required)
    A short summary of the error type.
Use detail for information specific to this occurrence.
    Example: "Forbidden"

  - `status` (integer, required)
    The HTTP status code for this error.
Matches the status code of the HTTP response.
    Example: 403

  - `detail` (string)
    A human-readable explanation of what went wrong in this specific case.
May be localized.
    Example: "You do not have permission to perform this action"

  - `instance` (string)
    A URI that identifies this specific error occurrence.
Include this value when contacting support.

  - `code` (string, required)
    Stable machine-readable error code ({domain}.{reason}) for programmatic error handling. Unlike the HTTP status or free-form detail, this code is guaranteed not to change between versions for a given error condition, so it is safe to branch on in client code. Defaults to unspecified when the server has not assigned a specific code.
    Example: "chain.not_allowed"

## Response 422 fields (application/problem+json):

  - `type` (string, required)
    A URI that identifies the error type.
Open it in a browser to read about this category of error.
    Example: "https://docs.vilna.io/apis/problems/precondition-failed"

  - `title` (string, required)
    A short summary of the error type.
Use detail for information specific to this occurrence.
    Example: "Precondition Failed"

  - `status` (integer, required)
    The HTTP status code for this error.
Matches the status code of the HTTP response.
    Example: 422

  - `detail` (string)
    A human-readable explanation of what went wrong in this specific case.
May be localized.
    Example: "The request cannot be processed due to failed business rule validation"

  - `instance` (string)
    A URI that identifies this specific error occurrence.
Include this value when contacting support.

  - `code` (string, required)
    Stable machine-readable error code ({domain}.{reason}) for programmatic error handling. Unlike the HTTP status or free-form detail, this code is guaranteed not to change between versions for a given error condition, so it is safe to branch on in client code. Defaults to unspecified when the server has not assigned a specific code.
    Example: "simulation.failed"

  - `fields` (array)
    List of fields that failed precondition validation

  - `fields.name` (string, required)
    The name of the field that failed validation
    Example: "status"

  - `fields.reason` (string, required)
    Why the precondition failed for this field
    Example: "Cannot transition from archived to active state"

## Response default fields (application/problem+json):

  - `type` (string, required)
    A URI that identifies the error type.
Open it in a browser to read about this category of error.

  - `title` (string, required)
    A short summary of the error type.
Use detail for information specific to this occurrence.

  - `status` (integer, required)
    The HTTP status code for this error.
Matches the status code of the HTTP response.

  - `detail` (string)
    A human-readable explanation of what went wrong in this specific case.
May be localized.

  - `instance` (string)
    A URI that identifies this specific error occurrence.
Include this value when contacting support.

  - `code` (string, required)
    Stable machine-readable error code ({domain}.{reason}) for programmatic error handling. Unlike the HTTP status or free-form detail, this code is guaranteed not to change between versions for a given error condition, so it is safe to branch on in client code. Defaults to unspecified when the server has not assigned a specific code.