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

# Get the wallet message for a builder trading key

> Public endpoint. Returns a SIWE message for the supplied wallet address and nonzero builder-code UUID, with a random nonce and ten-minute validity window. Sign the returned message unchanged and submit it to POST /builder/web3/api-key. This endpoint does not check whether the builder exists or is active.



## OpenAPI

````yaml /api-reference/openapi.yaml get /builder/web3/message
openapi: 3.1.0
info:
  contact:
    email: support@qfex.com
    name: QFEX Support
  description: REST API for QFEX
  license:
    name: QFEX License
    url: https://qfex.com/license
  title: QFEX REST API
  version: 0.1.0
servers:
  - description: Production server
    url: https://api.qfex.com
security: []
paths:
  /builder/web3/message:
    servers:
      - url: https://api.qfex.io
        description: Pre-production
    get:
      tags:
        - builder
      summary: Get the wallet message for a builder trading key
      description: >-
        Public endpoint. Returns a SIWE message for the supplied wallet address
        and nonzero builder-code UUID, with a random nonce and ten-minute
        validity window. Sign the returned message unchanged and submit it to
        POST /builder/web3/api-key. This endpoint does not check whether the
        builder exists or is active.
      operationId: builder-web3-message
      parameters:
        - in: query
          name: address
          required: true
          schema:
            pattern: ^0x[0-9a-fA-F]{40}$
            type: string
        - in: query
          name: builder_code
          description: The builder's nonzero builder-code UUID.
          required: true
          schema:
            format: uuid
            type: string
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BuilderWalletMessageResponseBody'
          description: OK
          headers:
            Cache-Control:
              schema:
                type: string
                const: no-store
        default:
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/ErrorModel'
          description: Error
      security: []
components:
  schemas:
    BuilderWalletMessageResponseBody:
      additionalProperties: false
      properties:
        message:
          description: >-
            EIP-4361 message containing the wallet address, builder
            authorization, random nonce, chain ID 1, and a ten-minute validity
            window.
          type: string
      required:
        - message
      type: object
    ErrorModel:
      additionalProperties: false
      properties:
        $schema:
          description: A URL to the JSON Schema for this object.
          examples:
            - https://api.qfex.com/schemas/ErrorModel.json
          format: uri
          readOnly: true
          type: string
        detail:
          description: >-
            A human-readable explanation specific to this occurrence of the
            problem.
          examples:
            - Property foo is required but is missing.
          type: string
        errors:
          description: Optional list of individual error details
          items:
            $ref: '#/components/schemas/ErrorDetail'
          type:
            - array
            - 'null'
        instance:
          description: >-
            A URI reference that identifies the specific occurrence of the
            problem.
          examples:
            - https://example.com/error-log/abc123
          format: uri
          type: string
        status:
          description: HTTP status code
          examples:
            - 400
          format: int64
          type: integer
        title:
          description: >-
            A short, human-readable summary of the problem type. This value
            should not change between occurrences of the error.
          examples:
            - Bad Request
          type: string
        type:
          default: about:blank
          description: A URI reference to human-readable documentation for the error.
          examples:
            - https://example.com/errors/example
          format: uri
          type: string
      type: object
    ErrorDetail:
      additionalProperties: false
      properties:
        location:
          description: >-
            Where the error occurred, e.g. 'body.items[3].tags' or
            'path.thing-id'
          type: string
        message:
          description: Error message text
          type: string
        value:
          description: The value at the given location
      type: object

````

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