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

# Append rows

> Append rows to the stream. Every row is validated against the locked format; one bad row rejects the whole batch (nothing is written). A correction is a new row with `supersedes` naming the row it replaces — it takes effect in snapshots cut from now on, older snapshots keep the original. Emits one `dataset.rows_appended` webhook per batch.



## OpenAPI

````yaml /api-reference/openapi.json post /v1/datasets/{dataset_id}/rows
openapi: 3.1.0
info:
  title: Veri API
  description: >-
    REST API for the Veri RL post-training platform. All requests require a
    Bearer API key (`vk_` prefix).
  license:
    name: ''
  version: 0.1.0
servers:
  - url: https://api.veri.studio
    description: Production
security: []
tags:
  - name: Training jobs
    description: Create, monitor, and manage training jobs.
  - name: Datasets
    description: Upload and connect training datasets.
  - name: Deployments
    description: Serve trained models and run inference.
  - name: Volumes
    description: Persistent file storage mounted into jobs.
  - name: Models
    description: Custom model registry deployments serve from.
  - name: Regions
    description: Discover available launch regions.
  - name: GPU
    description: Live GPU availability by provider and region.
  - name: Compatibility
    description: Advisory model and runtime compatibility guidance.
  - name: Code artifacts
    description: Upload custom training script bundles.
  - name: Billing
    description: Credit balance and transaction history.
  - name: API keys
    description: Create and revoke API keys.
  - name: Account
    description: The authenticated caller's identity.
  - name: SSH keys
    description: Manage SSH key pairs for compute access.
  - name: Settings
    description: Account-level integrations (Weights & Biases).
  - name: Metrics
    description: Prometheus metrics export for your own observability stack.
paths:
  /v1/datasets/{dataset_id}/rows:
    post:
      tags:
        - Datasets
      summary: Append rows
      description: >-
        Append rows to the stream. Every row is validated against the locked
        format; one bad row rejects the whole batch (nothing is written). A
        correction is a new row with `supersedes` naming the row it replaces —
        it takes effect in snapshots cut from now on, older snapshots keep the
        original. Emits one `dataset.rows_appended` webhook per batch.
      operationId: append_rows
      parameters:
        - name: dataset_id
          in: path
          description: Dataset ID or name
          required: true
          schema:
            type: string
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AppendRowsRequest'
        required: true
      responses:
        '201':
          description: The appended row range
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AppendResult'
        '400':
          description: >-
            Format mismatch, empty batch, or a supersedes target that does not
            exist
        '404':
          description: Not found or not owned by the caller
      security:
        - bearerAuth: []
components:
  schemas:
    AppendRowsRequest:
      oneOf:
        - type: array
          items: {}
        - type: object
          required:
            - rows
          properties:
            rows:
              type: array
              items: {}
        - type: object
          required:
            - row
            - supersedes
          properties:
            row:
              type: object
            supersedes:
              type: integer
              format: int64
      description: |-
        `POST /v1/datasets/{id}/rows` accepts three shapes:
          * a bare JSON array of rows: `[{...}, {...}]`
          * `{"rows": [{...}, ...]}`
          * a single correction: `{"row": {...}, "supersedes": 12}`
    AppendResult:
      type: object
      required:
        - dataset_id
        - first_row
        - last_row
        - count
        - format
        - head_row
      properties:
        dataset_id:
          type: string
        first_row:
          type: integer
          format: int64
          description: row_id of the first entry in this batch.
        last_row:
          type: integer
          format: int64
          description: row_id of the last entry in this batch (== the new stream head).
        count:
          type: integer
          format: int64
        format:
          $ref: '#/components/schemas/RowFormat'
        head_row:
          type: integer
          format: int64
    RowFormat:
      type: string
      description: |-
        The locked row format of a stream. Detected from the first row and
        enforced on every later append (a mismatched row 400s the whole batch).
      enum:
        - prompt
        - preference
        - completion
        - chat
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API key
      description: API key with the `vk_` prefix. Create one from the dashboard.

````