> ## 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.

# Run several operations in one request (batch)

> POST a FHIR `Bundle` with `type: batch` to run several operations in one round trip. Entries are independent: one unknown code does not fail the others, and each carries its own status in the `batch-response`. Measured against the upstream, a batch of 50 lookups costs about 4.8 ms per code versus 181 ms sequentially. Transaction bundles are not accepted — these operations do not write, so atomicity would only turn one bad code into a wholly failed request.



## OpenAPI

````yaml /api-reference/openapi.json post /v1/fhir/r4
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.
paths:
  /v1/fhir/r4:
    post:
      tags:
        - Terminology
      summary: Run several operations in one request (batch)
      description: >-
        POST a FHIR `Bundle` with `type: batch` to run several operations in one
        round trip. Entries are independent: one unknown code does not fail the
        others, and each carries its own status in the `batch-response`.
        Measured against the upstream, a batch of 50 lookups costs about 4.8 ms
        per code versus 181 ms sequentially. Transaction bundles are not
        accepted — these operations do not write, so atomicity would only turn
        one bad code into a wholly failed request.
      operationId: fhirBatch
      requestBody:
        required: true
        content:
          application/fhir+json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: >-
            A FHIR `Bundle` with `type: batch-response`, one entry per request
            entry.
          content:
            application/fhir+json:
              schema:
                type: object
                additionalProperties: true
        '400':
          description: The body was not a batch Bundle.
          content:
            application/fhir+json:
              schema:
                $ref: '#/components/schemas/OperationOutcome'
        '401':
          description: Missing or invalid API key.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AuthError'
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>`.

````