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

# Build register trader instructions

> Returns the register and delegated-onboarding instructions for the default trader account without a referral code. The caller chooses the transaction fee payer, builds the transaction locally, and signs it with the trader authority and fee payer.



## OpenAPI

````yaml /openapi/phoenix-public-api.json post /v1/exchange/build-register-ixs
openapi: 3.1.0
info:
  title: Phoenix Eternal API
  description: >-
    RESTful API for accessing Phoenix Eternal perpetual trading data. Provides
    real-time orderbook levels, asset information, and market metadata.
  termsOfService: https://www.phoenix.trade/terms-of-service
  contact:
    name: Phoenix Development Team
    url: https://github.com/Ellipsis-Labs/phoenix
  license:
    name: Proprietary
  version: 1.0.0
servers:
  - url: https://perp-api.phoenix.trade
    description: Phoenix Eternal Perp API
security: []
tags:
  - name: Auth
    description: Wallet and session authentication.
  - name: Exchange
    description: Exchange, market, candle, and no-referral register-instruction workflows.
  - name: Invite
    description: Invite validation, referral activation, and wallet allowlist checks.
  - name: Notifications
    description: Trader notification reads and acknowledgement helpers.
  - name: Trader
    description: Trader state, account history, and transaction builders.
externalDocs:
  url: https://docs.phoenix.trade
  description: Phoenix developer documentation
paths:
  /v1/exchange/build-register-ixs:
    post:
      tags:
        - Exchange
      summary: Build register trader instructions
      description: >-
        Returns the register and delegated-onboarding instructions for the
        default trader account without a referral code. The caller chooses the
        transaction fee payer, builds the transaction locally, and signs it with
        the trader authority and fee payer.
      operationId: post.v1.exchange.build_register_ixs
      requestBody:
        description: JSON request payload for `post.v1.exchange.build_register_ixs`.
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/BuildRegisterIxsRequest'
            example:
              traderAuthority: string
              txFeePayer: string
        required: true
      responses:
        '200':
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BuildRegisterIxsResponse'
components:
  schemas:
    BuildRegisterIxsRequest:
      type: object
      description: Request payload for /exchange/build-register-ixs.
      required:
        - traderAuthority
        - txFeePayer
      properties:
        maxPositions:
          type:
            - integer
            - 'null'
          format: int32
          minimum: 0
        traderAuthority:
          type: string
        txFeePayer:
          type: string
    BuildRegisterIxsResponse:
      type: object
      description: Response payload for /exchange/build-register-ixs.
      required:
        - instructions
        - traderPda
        - traderOnboarder
        - txFeePayer
        - maxPositions
        - includeRegisterTrader
      properties:
        includeRegisterTrader:
          type: boolean
        instructions:
          type: array
          items:
            $ref: '#/components/schemas/ApiInstructionResponse'
        maxPositions:
          type: integer
          format: int32
          minimum: 0
        traderOnboarder:
          type: string
        traderPda:
          type: string
        txFeePayer:
          type: string
    ApiInstructionResponse:
      type: object
      description: |-
        API representation of a Solana instruction.

        Note: this is a pure DTO. When needed, clients/servers can enable the
        appropriate conversion logic in the consumer crate to avoid forcing a
        Solana dependency in `phoenix-api-types`.
      required:
        - data
        - keys
        - programId
      properties:
        data:
          type: array
          items:
            type: integer
            format: int32
            minimum: 0
        keys:
          type: array
          items:
            $ref: '#/components/schemas/ApiAccountMeta'
        programId:
          type: string
    ApiAccountMeta:
      type: object
      description: Account metadata returned from instruction-building endpoints.
      required:
        - pubkey
        - isSigner
        - isWritable
      properties:
        isSigner:
          type: boolean
        isWritable:
          type: boolean
        pubkey:
          type: string

````