> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stableyard.fi/llms.txt
> Use this file to discover all available pages before exploring further.

# Create a smart wallet

> Creates (or, if one already exists for this account and chain, returns) a Safe/Zodiac-controlled smart wallet on Arbitrum for account-bound spend policies. `policy` and `setupTransaction` are present only when policy setup was computed for a newly created wallet; an existing wallet is returned as-is with both omitted.

Create or retrieve the account’s Safe/Zodiac-controlled smart wallet on Arbitrum. Policy and setup transaction details are returned only when computed for a newly created wallet.


## OpenAPI

````yaml openapi.json POST /v2/accounts/{accountId}/smart-wallets
openapi: 3.1.0
info:
  title: Stableyard Partner API
  version: 2.0.0-staging
  x-stableyard-api-version: '2026-09-09'
  x-stableyard-supported-api-versions:
    - '2026-09-09'
  summary: Backend API for UPAs, Payments, activity, and optional financial products.
  description: >

    Use this API from a trusted partner backend with an app ID and app secret.


    ## Recommended integration


    1. Call `GET /v2/partners/config` to verify credentials and discover enabled
    capabilities.

    2. Create a UPA only when your product needs a persistent Stableyard
    account.

    3. Create a receive or send Payment with `POST /v2/payments`.

    4. Redirect a payer to the returned `paymentUrl` or pass the Payment
    credentials to an official Stableyard interface SDK.

    5. Process signed webhooks and fetch the Payment by ID for reconciliation.


    Checkout execution and account-bound browser endpoints are intentionally
    documented in the separate Interfaces & SDKs reference. Console endpoints
    are dashboard implementation details and are not part of the partner
    integration contract.
  x-stableyard-documentation-surface: partner
servers:
  - url: https://prod-api.stableyard.fi
    description: Production
  - url: https://staging-api-v2.stableyard.fi
    description: Staging
  - url: http://localhost:3001
    description: Local
security: []
tags:
  - name: Authentication
    x-displayName: API authentication
    description: Verify your app ID and app secret before calling UPA APIs.
  - name: Accounts
    x-displayName: UPA Accounts
    description: Create Universal Payment Accounts and manage account settings.
  - name: Deposit Addresses
    description: Create reusable receive addresses and verify inbound deposits.
  - name: Identity & KYC
    description: >-
      Verify the UPA email and run provider-neutral identity verification.
      Managed vaults and fiat payment rails use this same verified UPA identity.
  - name: Vaults
    description: >-
      Create Safe/Zodiac controlled stablecoin vaults and manage policy updates
      for accounts.
  - name: Payments
    description: >-
      Create escrow-first payments, issue partner-authenticated send
      instructions or executions, power public checkout, and reconcile
      collection through final account settlement.
  - name: Balances & Transactions
    description: >-
      Read Stableyard-posted financial activity. Balances are ledger projections
      of activity Stableyard processed; they are not live balances of externally
      controlled wallets.
paths:
  /v2/accounts/{accountId}/smart-wallets:
    post:
      tags:
        - Vaults
      summary: Create a smart wallet
      description: >-
        Creates (or, if one already exists for this account and chain, returns)
        a Safe/Zodiac-controlled smart wallet on Arbitrum for account-bound
        spend policies. `policy` and `setupTransaction` are present only when
        policy setup was computed for a newly created wallet; an existing wallet
        is returned as-is with both omitted.
      operationId: createSmartWallet
      parameters:
        - name: accountId
          in: path
          required: true
          schema:
            type: string
            example: acct_123
          description: Canonical account id returned by the Accounts API.
        - name: Stableyard-Version
          in: header
          required: false
          schema:
            type: string
            enum:
              - '2026-09-09'
          description: >-
            Optional contract-version assertion. Omit it to use the app
            environment's pinned version. A different supported version is
            accepted only after that environment is explicitly migrated.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateSmartWalletRequest'
            examples:
              example:
                summary: Create a smart wallet request
                value:
                  mode: external_owner
                  ownerAddress: '0x1111111111111111111111111111111111111111'
                  maxTransferAtomic: '1000000'
                  spendLimitAtomic: '1000000'
                  metadata: {}
      responses:
        '200':
          description: Smart wallet
          headers:
            Stableyard-Version:
              description: >-
                Effective date-based Stableyard API contract version for this
                response.
              schema:
                type: string
                enum:
                  - '2026-09-09'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CreateSmartWalletResponse'
              examples:
                example:
                  summary: Create a smart wallet 200 response
                  value:
                    smartWallet:
                      id: resource_123
                      accountId: acct_123
                      environmentId: environment_123
                      mode: external_owner
                      chainId: 1
                      status: example
                      createdAt: '2026-08-28T10:00:00.000Z'
                      updatedAt: '2026-08-28T10:00:00.000Z'
                    policy:
                      id: resource_123
                      smartWalletId: smartwallet_123
                      version: 1
                      roleKey: example
                      executorAddress: '0x1111111111111111111111111111111111111111'
                      tokenAddress: '0x1111111111111111111111111111111111111111'
                      maxTransferAtomic: '1000000'
                      status: example
                    setupTransaction: {}
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          $ref: '#/components/responses/NotFound'
        '409':
          $ref: '#/components/responses/Conflict'
        '424':
          $ref: '#/components/responses/FailedDependency'
        '429':
          $ref: '#/components/responses/TooManyRequests'
      security:
        - partnerBasicAuth: []
components:
  schemas:
    CreateSmartWalletRequest:
      type: object
      properties:
        mode:
          type: string
          enum:
            - external_owner
            - managed
        ownerAddress:
          type: string
          description: EVM address. Required for external_owner mode.
        maxTransferAtomic:
          type: string
        spendLimitAtomic:
          type: string
        metadata:
          type: object
          additionalProperties: true
          description: >-
            Optional partner metadata. Must be JSON-safe, at most 4096 bytes,
            depth 3, 25 keys per object, 512 characters per string, and 50 items
            per array.
    CreateSmartWalletResponse:
      type: object
      required:
        - smartWallet
      properties:
        smartWallet:
          type: object
          required:
            - id
            - accountId
            - environmentId
            - mode
            - chainId
            - status
            - createdAt
            - updatedAt
          properties:
            id:
              type: string
            accountId:
              type: string
            environmentId:
              type: string
            mode:
              type: string
              enum:
                - external_owner
                - managed
            chainId:
              type: integer
              description: This product is Arbitrum-only today.
            safeAddress:
              type:
                - string
                - 'null'
            rolesModuleAddress:
              type:
                - string
                - 'null'
            ownerAddress:
              type:
                - string
                - 'null'
            status:
              type: string
            activePolicyVersion:
              type:
                - integer
                - 'null'
            createdAt:
              type: string
              format: date-time
            updatedAt:
              type: string
              format: date-time
        policy:
          type: object
          description: >-
            Present only when policy setup was computed for a newly created
            wallet.
          properties:
            id:
              type: string
            smartWalletId:
              type: string
            version:
              type: integer
            roleKey:
              type: string
            executorAddress:
              type: string
            tokenAddress:
              type: string
            maxTransferAtomic:
              type: string
            status:
              type: string
            createdAt:
              type: string
              format: date-time
            updatedAt:
              type: string
              format: date-time
        setupTransaction:
          type: object
          additionalProperties: true
          description: >-
            Present only alongside `policy`. An unsigned Safe transaction
            payload the caller must sign and broadcast to finish on-chain vault
            setup.
    ErrorResponse:
      type: object
      additionalProperties: false
      required:
        - error
      properties:
        error:
          type: object
          additionalProperties: false
          required:
            - code
            - message
          properties:
            code:
              type: string
              minLength: 1
              maxLength: 128
              example: bad_request
            message:
              type: string
              minLength: 1
              maxLength: 1000
              example: The request is invalid
            details: {}
  responses:
    BadRequest:
      description: Bad request
      headers:
        Stableyard-Version:
          description: >-
            Effective date-based Stableyard API contract version for this
            response.
          schema:
            type: string
            enum:
              - '2026-09-09'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            example:
              summary: BadRequest response
              value:
                error:
                  code: bad_request
                  message: The request is invalid
                  details: example
    Unauthorized:
      description: Unauthorized
      headers:
        Stableyard-Version:
          description: >-
            Effective date-based Stableyard API contract version for this
            response.
          schema:
            type: string
            enum:
              - '2026-09-09'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            example:
              summary: Unauthorized response
              value:
                error:
                  code: bad_request
                  message: The request is invalid
                  details: example
    Forbidden:
      description: The app secret does not include the required scope
      headers:
        Stableyard-Version:
          description: >-
            Effective date-based Stableyard API contract version for this
            response.
          schema:
            type: string
            enum:
              - '2026-09-09'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            example:
              summary: Forbidden response
              value:
                error:
                  code: bad_request
                  message: The request is invalid
                  details: example
    NotFound:
      description: Not found
      headers:
        Stableyard-Version:
          description: >-
            Effective date-based Stableyard API contract version for this
            response.
          schema:
            type: string
            enum:
              - '2026-09-09'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            example:
              summary: NotFound response
              value:
                error:
                  code: bad_request
                  message: The request is invalid
                  details: example
    Conflict:
      description: Conflict
      headers:
        Stableyard-Version:
          description: >-
            Effective date-based Stableyard API contract version for this
            response.
          schema:
            type: string
            enum:
              - '2026-09-09'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            example:
              summary: Conflict response
              value:
                error:
                  code: bad_request
                  message: The request is invalid
                  details: example
    FailedDependency:
      description: Required chain, network, or provider configuration is missing
      headers:
        Stableyard-Version:
          description: >-
            Effective date-based Stableyard API contract version for this
            response.
          schema:
            type: string
            enum:
              - '2026-09-09'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            example:
              summary: FailedDependency response
              value:
                error:
                  code: bad_request
                  message: The request is invalid
                  details: example
    TooManyRequests:
      description: >-
        Rate limit, payment-option limit, selection cooldown, or temporary abuse
        block
      headers:
        Stableyard-Version:
          description: >-
            Effective date-based Stableyard API contract version for this
            response.
          schema:
            type: string
            enum:
              - '2026-09-09'
        Retry-After:
          description: Seconds until the caller should retry.
          schema:
            type: integer
            minimum: 1
        RateLimit-Limit:
          description: Quota for the most constrained policy.
          schema:
            type: integer
            minimum: 1
        RateLimit-Remaining:
          description: Requests remaining in that policy window.
          schema:
            type: integer
            minimum: 0
        RateLimit-Reset:
          description: Seconds until that policy window resets.
          schema:
            type: integer
            minimum: 0
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            example:
              summary: TooManyRequests response
              value:
                error:
                  code: bad_request
                  message: The request is invalid
                  details: example
  securitySchemes:
    partnerBasicAuth:
      type: http
      scheme: basic
      description: >-
        HTTP Basic auth. Username is the Stableyard app ID. Password is the app
        secret. The optional Stableyard-Version request header must match the
        environment pin.

````

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