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

# Set a batch default schema

> Set the default published schema version for new batch documents.

Sets `default_struct_version` for **new** documents added to this batch. Existing rows keep the version they were extracted with until you reassign or reprocess them.


## OpenAPI

````yaml POST /api/v2/batches/{batch_id}/default-version/
openapi: 3.1.0
info:
  title: Abacus Docs API
  version: 1.0.0
  description: |
    REST + SSE surface for Abacus Docs on the same host as the web app
    (`https://abacusdocs.com`). Paths are `/api/v2/…`.

    Authenticate with an organisation API key (`sk-abacus-*`) as a Bearer
    token, or an Auth0 access token. Cross-tenant reads return **404**, not
    403. Page-based lists use `?page=` and `?page_size=`.

    Extraction, reprocess, schema tests, and chat turns spend credits.
    See the help centre Credits pages for rates.
  contact:
    name: Abacus Docs
    url: https://abacusdocs.com/contact
servers:
  - url: https://abacusdocs.com
    description: Production (Extract)
security: []
paths:
  /api/v2/batches/{batch_id}/default-version/:
    post:
      tags:
        - v2/batches
      summary: Reassign the default StructVersion for a batch
      description: >-
        Repoints ``Batch.default_struct_version`` at a different published
        version of the batch's parent struct. Only affects *future-added* docs
        (the seed for new ``BatchDocument`` rows added via the Phase 2
        add-documents endpoint). Already-existing docs keep whatever per-doc
        version they carry — to change those, use ``POST
        /api/v2/batches/{batch_id}/documents/{doc_id}/version/``.


        Validation:

        - The batch must already have a default version (plain   no-schema
        batches return 400 — there is no parent struct to   resolve against).

        - The target ``version_number`` must exist on the parent   struct (404
        otherwise).

        - Deprecated versions are rejected with 400 (deprecation marks   the
        version as decommissioned; new assignments must use a   healthy
        version).
      operationId: v2_batches_default_version_create
      parameters:
        - in: path
          name: batch_id
          schema:
            type: integer
          required: true
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/BatchVersionRequestRequest'
        required: true
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StructVersionSummary'
          description: ''
        '400':
          content:
            application/json:
              schema:
                type: object
                additionalProperties: {}
          description: ''
        '404':
          content:
            application/json:
              schema:
                type: object
                additionalProperties: {}
          description: ''
      security:
        - extractApiKey: []
        - bearerAuth: []
        - cookieAuth: []
components:
  schemas:
    BatchVersionRequestRequest:
      type: object
      description: >-
        Body for batch version reassignment endpoints (Task 16).


        Accepts a single ``version_number`` field; the consuming view resolves
        it

        against the parent batch's struct and rejects deprecated versions.
      properties:
        version_number:
          type: integer
          minimum: 1
      required:
        - version_number
    StructVersionSummary:
      type: object
      description: List shape for ``StructVersion`` rows (no schema body).
      properties:
        version_number:
          type: integer
          maximum: 2147483647
          minimum: 0
        published_at:
          type: string
          format: date-time
          readOnly: true
        published_by:
          oneOf:
            - $ref: '#/components/schemas/_PublishedBy'
            - type: 'null'
          readOnly: true
        publish_note:
          type: string
          maxLength: 500
        field_count:
          type: integer
          readOnly: true
        is_deprecated:
          type: boolean
          readOnly: true
        deprecated_at:
          type:
            - string
            - 'null'
          format: date-time
        deprecated_by:
          oneOf:
            - $ref: '#/components/schemas/_PublishedBy'
            - type: 'null'
          readOnly: true
        deprecation_note:
          type: string
          maxLength: 500
      required:
        - deprecated_by
        - field_count
        - is_deprecated
        - published_at
        - published_by
        - version_number
    _PublishedBy:
      type: object
      description: Compact projection of the user who published / deprecated a version.
      properties:
        id:
          type: integer
        email:
          type: string
          format: email
      required:
        - email
        - id
  securitySchemes:
    extractApiKey:
      type: http
      scheme: bearer
      bearerFormat: API Key
      description: |
        Organisation API key from Settings → API / `/api/keys/`. The secret is
        shown once. Send `Authorization: Bearer sk-abacus-…`. One active key
        per organisation. Ingest (`/api/v2/ingest/*`) refuses API keys — that
        surface is Auth0-only with `ingest:read` / `ingest:write` scopes.
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
      description: >
        Auth0 access token for a signed-in user. Send `Authorization: Bearer
        <token>`.

        The SPA and desktop agent use this. Prefer an organisation API key for

        server-to-server integrations.
    cookieAuth:
      type: apiKey
      in: cookie
      name: sessionid
      description: |
        Django session cookie from a browser login. Present so the web app can
        call `/api/v2` without a header. Do not rely on this for integrations.

````