> ## Documentation Index
> Fetch the complete documentation index at: https://docs.haau3.com/llms.txt
> Use this file to discover all available pages before exploring further.

# List or find a questionnaire

> Search the questionnaires this service serves. With no parameters it lists every one of them, which is how you discover what is available.

Two parameters are offered: `url` (the canonical, optionally as `{url}|{version}`) and `version`. Every other parameter, `status` included, is refused by name rather than ignored, so a search never quietly answers a different question than the one asked. Results are never paged: one page, with `total` set.

Questionnaires are served exactly as their source publishes them. Each carries its own `copyright`, which must be kept with the form wherever it goes.



## OpenAPI

````yaml /api-reference/openapi.json get /v1/fhir/r4/Questionnaire
openapi: 3.1.0
info:
  title: haau3 Platform API
  version: 1.0.0
  description: >-
    The haau3 platform API (non-PHI). Endpoints require a free API key — send it
    as `Authorization: Bearer <key>`. Requests without a valid key return 401.
    Create a key in the dashboard at https://platform.haau3.com.
servers:
  - url: https://api.haau3.com
    description: Production
security:
  - bearerAuth: []
tags:
  - name: Scheduling
    description: Provider availability (SMART Scheduling Links) — slots and publishers.
  - name: Terminology
    description: FHIR terminology operations — CodeSystem lookups against LOINC.
  - name: Provider directory
    description: >-
      FHIR Practitioner and PractitionerRole, resolved from the national
      provider directory. Resolution, not discovery: bring an NPI and get what
      the directory publishes for it.
  - name: Questionnaires
    description: >-
      FHIR Questionnaire, served as its source publishes it. Search a curated
      set by canonical URL or version, read one by id, and build the
      QuestionnaireResponse in your own application.
paths:
  /v1/fhir/r4/Questionnaire:
    get:
      tags:
        - Questionnaires
      summary: List or find a questionnaire
      description: >-
        Search the questionnaires this service serves. With no parameters it
        lists every one of them, which is how you discover what is available.


        Two parameters are offered: `url` (the canonical, optionally as
        `{url}|{version}`) and `version`. Every other parameter, `status`
        included, is refused by name rather than ignored, so a search never
        quietly answers a different question than the one asked. Results are
        never paged: one page, with `total` set.


        Questionnaires are served exactly as their source publishes them. Each
        carries its own `copyright`, which must be kept with the form wherever
        it goes.
      operationId: searchQuestionnaire
      parameters:
        - name: url
          in: query
          required: false
          schema:
            type: string
          description: >-
            Exact match on the canonical URL, for example
            `http://loinc.org/q/44249-1`. The `{url}|{version}` form is accepted
            and matches that version only; a version that is not served answers
            an empty searchset rather than a different version.
        - name: version
          in: query
          required: false
          schema:
            type: string
          description: >-
            Exact match on the business version. The served questionnaires carry
            their source release as their version.
      responses:
        '200':
          description: >-
            A `searchset` Bundle with `total` set. Every match is in this one
            page.
          content:
            application/fhir+json:
              schema:
                type: object
                additionalProperties: true
        '400':
          description: >-
            A parameter this service does not serve, a repeated parameter, or a
            comma-separated list of values. One issue per offending parameter,
            naming it.
          content:
            application/fhir+json:
              schema:
                $ref: '#/components/schemas/OperationOutcome'
        '401':
          description: Missing or invalid API key.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AuthError'
        '406':
          description: >-
            A FHIR release this endpoint does not serve was requested via the
            `fhirVersion` media-type parameter.
          content:
            application/fhir+json:
              schema:
                $ref: '#/components/schemas/OperationOutcome'
components:
  schemas:
    OperationOutcome:
      type: object
      properties:
        resourceType:
          type: string
          enum:
            - OperationOutcome
        issue:
          type: array
          items:
            type: object
            properties:
              severity:
                type: string
                enum:
                  - fatal
                  - error
                  - warning
                  - information
              code:
                type: string
              details:
                type: object
                properties:
                  text:
                    type: string
                additionalProperties: true
              diagnostics:
                type: string
              expression:
                type: array
                items:
                  type: string
            required:
              - severity
              - code
            additionalProperties: true
      required:
        - resourceType
        - issue
    AuthError:
      type: object
      properties:
        error:
          type: string
          examples:
            - API key required
        message:
          type: string
      required:
        - error
        - message
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        Your platform API key (`haau3_sk_…`), sent as `Authorization: Bearer
        <key>`.

````