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

# Delete evaluator versions

> **Endpoint:** `DELETE /v2/evaluators/{evaluator_id}/versions`

Deletes a batch of versions belonging to the evaluator identified by the
`evaluator_id` path parameter. This operation is irreversible.

The delete is partial-tolerant: versions that exist and belong to
`evaluator_id` are deleted; every requested ID that was not deleted is
reported back in `not_deleted_version_ids` (for example, because a version
was not found or belongs to a different evaluator). This is not an error —
the response is still `200`.

Deleting a version currently pinned to a running online task un-pins that
task; it falls back to resolving the evaluator's latest version.

**Payload Requirements**
- `version_ids` must contain between 1 and 100 IDs. Duplicate IDs are accepted
  and silently collapsed so each version is processed at most once.

**Responses**
- `200` — request processed. Check `deleted_version_ids` /
  `not_deleted_version_ids` for the outcome of each requested ID.
- `400` — malformed request: `evaluator_id` fails ID-format validation
  (`Invalid evaluator ID format`), or `version_ids` is missing/empty
  (`version_ids must contain at least one evaluator version ID`), not an
  array (`version_ids must be an array`), exceeds 100 entries
  (`version_ids cannot contain more than 100 evaluator version IDs`), or
  one entry fails ID-format validation
  (`Invalid evaluator version ID format`).
- `401` — missing or invalid credentials.
- `403` — the evaluator is readable but the caller lacks permission to
  delete its versions.
- `404` — `evaluator_id` does not exist or is not readable by the caller
  (`Evaluator not found`).
- `429` — rate limit exceeded.

**Valid example** — evaluator `RXZhbHVhdG9yOjEyOkI3cmk=` with a single
version `RXZhbHVhdG9yVmVyc2lvbjozMjpBQ0Q2`:
```json
{
  "version_ids": ["RXZhbHVhdG9yVmVyc2lvbjozMjpBQ0Q2"]
}
```
Response `200`:
```json
{
  "completed": true,
  "deleted_version_ids": ["RXZhbHVhdG9yVmVyc2lvbjozMjpBQ0Q2"],
  "not_deleted_version_ids": []
}
```

**Invalid example** (empty `version_ids`)
```json
{
  "version_ids": []
}
```
Response `400`:
```json
{
  "status": 400,
  "title": "Bad Request",
  "type": "https://arize.com/docs/ax/rest-reference/errors#invalid-request",
  "detail": "version_ids must contain at least one evaluator version ID"
}
```

<Note>This endpoint is in beta, read more [here](https://arize.com/docs/ax/rest-reference#api-version-stages).</Note>




## OpenAPI

````yaml https://api.arize.com/v2/spec.yaml delete /v2/evaluators/{evaluator_id}/versions
openapi: 3.0.3
info:
  title: Arize REST API
  version: 2.0.0
  description: |
    API specification for the backend data server. The API is hosted globally
    at https://api.arize.com/v2 or in your own environment.
  license:
    name: Apache-2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
servers:
  - description: Global
    url: https://api.arize.com
  - description: Regional
    url: https://api.{region}.arize.com
    variables:
      region:
        default: eu-west-1a
        enum:
          - eu-west-1a
          - ca-central-1a
  - description: Custom Host
    url: https://{host}
    variables:
      host:
        default: api.arize.com
security:
  - bearerAuth: []
tags:
  - name: AI Integrations
    description: |
      AI integrations configure access to external LLM providers (e.g. OpenAI,
      Azure OpenAI, AWS Bedrock, Vertex AI). Integrations can be scoped to the
      entire account, a specific organization, or a specific space.
  - name: Annotation Configs
    description: >
      Annotation configs allow you to define consistent annotation schemas that

      can be reused across your workspace, ensuring evaluations are structured
      and

      comparable over time.
  - name: Annotation Queues
    description: >
      Annotation queues help you organize and manage human evaluation workflows.

      Use queues to assign spans or examples to annotators for review and
      labeling.
  - name: API Keys
    description: >
      API keys are used to authenticate requests to the Arize API. List your
      keys

      to view metadata; the raw secret is never returned after creation.
  - name: Audit Logs
    description: >
      Audit logs record authenticated user actions within an account, providing
      a

      chronological trail for security and compliance review. Access requires

      account admin privileges and audit logging to be enabled.
  - name: Datasets
    description: |
      Datasets are structured, version-controlled example collections you use to
      run, evaluate, and track LLM experiments.
  - name: Evaluators
    description: >
      Evaluators are reusable evaluation configurations used to assess the
      quality

      of LLM outputs. They can be template-based (using LLM judges) or
      code-based.
  - name: Experiments
    description: >
      Experiments let you systematically test prompt/model changes using
      datasets,

      tasks, and evaluators.
  - name: Integrations
    description: >
      Integrations configure access to external LLM providers (e.g. OpenAI,

      Azure OpenAI, AWS Bedrock, Vertex AI), notifications services (e.g.
      PagerDuty, Slack), and

      your own agents. Integrations can be scoped to the entire account, a
      specific

      organization, or a specific space.
  - name: Monitors
    description: >
      Monitors continuously track a metric over your model or LLM application
      data

      and alert you when it crosses a threshold. Each monitor watches a single

      metric - data quality, model performance, drift, a custom metric, or a

      tracing metric - and moves between statuses as the metric passes in and
      out of its 

      healthy range.
  - name: Organizations
    description: >
      Organizations are top-level containers within an Arize AX account for
      grouping spaces.
  - name: Projects
    description: |
      Projects represent LLM applications being monitored in Arize where you can
      observe traces and spans.
  - name: Prompts
    description: >
      Prompts are reusable, versioned templates for LLM interactions. Use
      prompts

      to standardize and manage how you interact with LLMs across your
      application.
  - name: Resource Restrictions
    description: |
      Endpoints for restricting and unrestricting resources (projects, models).
  - name: Role Bindings
    description: |
      Role bindings assign a role to a user on a resource. REST currently
      supports space- and project-scoped bindings.
  - name: Roles
    description: >
      Roles define sets of permissions that can be assigned to users within an

      account. Create custom roles to tailor access control to your team's
      needs.
  - name: Spaces
    description: >
      Spaces are containers within an organization for grouping related
      projects,

      datasets, and experiments, enabling collaboration or isolated
      experimentation

      with role-based access control.
  - name: Spans
    description: |
      Spans represent individual operations within a trace. A span captures the
      timing, status, and attributes of a single operation in your application.
  - name: Tags
    description: |
      Tags are reusable labels defined once per space and attached to resources
      across the platform, so the same vocabulary can be applied to projects,
      datasets, prompts, and more. Tags are shared: renaming or deleting a tag
      affects every resource it is attached to.
  - name: Tasks
    description: |
      Tasks are configurable units of work that tie one or more evaluators to a
      data source (project or dataset). Use tasks to automate evaluation of LLM
      outputs, with support for continuous evaluation and backfill runs.
  - name: Traces
    description: |
      A trace is the collection of spans sharing a trace ID, representing a
      single end-to-end request through an LLM application. Use the Traces
      endpoint to retrieve traces with all of their spans in one call.
  - name: Users
    description: >
      Users represent members of an account. The Users endpoints allow creating,

      listing, updating (display name), and removing users from the account
      programmatically.
  - name: Webhooks
    description: >
      Webhooks are organization-owned destinations that receive event deliveries

      over HTTPS. Deliveries are authenticated with a bearer token or signed
      with

      an HMAC signing secret — the secret is returned exactly once, when the

      webhook is created. Delivery attempts are recorded and can be listed for

      debugging. To choose which events a webhook receives, manage its

      subscriptions through the prompt and evaluator webhook-subscription

      endpoints.
paths:
  /v2/evaluators/{evaluator_id}/versions:
    delete:
      tags:
        - Evaluators
      summary: Delete evaluator versions
      description: >
        **Endpoint:** `DELETE /v2/evaluators/{evaluator_id}/versions`


        Deletes a batch of versions belonging to the evaluator identified by the

        `evaluator_id` path parameter. This operation is irreversible.


        The delete is partial-tolerant: versions that exist and belong to

        `evaluator_id` are deleted; every requested ID that was not deleted is

        reported back in `not_deleted_version_ids` (for example, because a
        version

        was not found or belongs to a different evaluator). This is not an error
        —

        the response is still `200`.


        Deleting a version currently pinned to a running online task un-pins
        that

        task; it falls back to resolving the evaluator's latest version.


        **Payload Requirements**

        - `version_ids` must contain between 1 and 100 IDs. Duplicate IDs are
        accepted
          and silently collapsed so each version is processed at most once.

        **Responses**

        - `200` — request processed. Check `deleted_version_ids` /
          `not_deleted_version_ids` for the outcome of each requested ID.
        - `400` — malformed request: `evaluator_id` fails ID-format validation
          (`Invalid evaluator ID format`), or `version_ids` is missing/empty
          (`version_ids must contain at least one evaluator version ID`), not an
          array (`version_ids must be an array`), exceeds 100 entries
          (`version_ids cannot contain more than 100 evaluator version IDs`), or
          one entry fails ID-format validation
          (`Invalid evaluator version ID format`).
        - `401` — missing or invalid credentials.

        - `403` — the evaluator is readable but the caller lacks permission to
          delete its versions.
        - `404` — `evaluator_id` does not exist or is not readable by the caller
          (`Evaluator not found`).
        - `429` — rate limit exceeded.


        **Valid example** — evaluator `RXZhbHVhdG9yOjEyOkI3cmk=` with a single

        version `RXZhbHVhdG9yVmVyc2lvbjozMjpBQ0Q2`:

        ```json

        {
          "version_ids": ["RXZhbHVhdG9yVmVyc2lvbjozMjpBQ0Q2"]
        }

        ```

        Response `200`:

        ```json

        {
          "completed": true,
          "deleted_version_ids": ["RXZhbHVhdG9yVmVyc2lvbjozMjpBQ0Q2"],
          "not_deleted_version_ids": []
        }

        ```


        **Invalid example** (empty `version_ids`)

        ```json

        {
          "version_ids": []
        }

        ```

        Response `400`:

        ```json

        {
          "status": 400,
          "title": "Bad Request",
          "type": "https://arize.com/docs/ax/rest-reference/errors#invalid-request",
          "detail": "version_ids must contain at least one evaluator version ID"
        }

        ```


        <Note>This endpoint is in beta, read more
        [here](https://arize.com/docs/ax/rest-reference#api-version-stages).</Note>
      operationId: delete_evaluator_versions
      parameters:
        - $ref: '#/components/parameters/EvaluatorIdPathParam'
      requestBody:
        $ref: '#/components/requestBodies/DeleteEvaluatorVersionsRequestBody'
      responses:
        '200':
          $ref: '#/components/responses/DeleteEvaluatorVersionsResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          $ref: '#/components/responses/NotFound'
        '429':
          $ref: '#/components/responses/RateLimitExceeded'
components:
  parameters:
    EvaluatorIdPathParam:
      name: evaluator_id
      in: path
      required: true
      description: The unique evaluator identifier (base64)
      schema:
        $ref: '#/components/schemas/Id'
      example: RXZhbHVhdG9yOjEyMzQ1
  requestBodies:
    DeleteEvaluatorVersionsRequestBody:
      required: true
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/DeleteEvaluatorVersionsRequest'
  responses:
    DeleteEvaluatorVersionsResponse:
      description: >
        Evaluator versions processed. A successful response includes `completed:
        true`

        because both result lists are complete. This does not indicate whether
        every

        requested version existed or was deleted. The delete is idempotent.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/DeleteEvaluatorVersionsResponse'
          examples:
            full_success:
              summary: All requested versions deleted
              value:
                completed: true
                deleted_version_ids:
                  - RXZhbHVhdG9yVmVyc2lvbjoxMDphQmNk
                  - RXZhbHVhdG9yVmVyc2lvbjoxMTphQmNk
                not_deleted_version_ids: []
            some_not_found:
              summary: One version was not found or did not belong to the evaluator
              value:
                completed: true
                deleted_version_ids:
                  - RXZhbHVhdG9yVmVyc2lvbjoxMDphQmNk
                not_deleted_version_ids:
                  - RXZhbHVhdG9yVmVyc2lvbjo5OTk6YUJjZA==
    BadRequest:
      description: Invalid request
      content:
        application/problem+json:
          schema:
            $ref: '#/components/schemas/Problem'
          example:
            status: 400
            title: Invalid request parameters
            detail: The 'name' field is required and must be a non-empty string.
            instance: /resource
            type: https://arize.com/docs/ax/rest-reference/errors#invalid-request
    Unauthorized:
      description: Authentication is required
      content:
        application/problem+json:
          schema:
            $ref: '#/components/schemas/Problem'
          example:
            status: 401
            title: Authentication required
            detail: You must be authenticated to access this resource.
            instance: /resource
            type: >-
              https://arize.com/docs/ax/rest-reference/errors#authentication-required
    Forbidden:
      description: Insufficient permissions to access this resource
      content:
        application/problem+json:
          schema:
            $ref: '#/components/schemas/Problem'
          example:
            status: 403
            title: Access forbidden
            detail: You do not have permission to access this resource.
            instance: /resource/12345
            type: https://arize.com/docs/ax/rest-reference/errors#access-forbidden
    NotFound:
      description: Not found
      content:
        application/problem+json:
          schema:
            $ref: '#/components/schemas/Problem'
          example:
            status: 404
            title: Resource not found
            detail: The requested resource with ID '12345' was not found.
            instance: /resource/12345
            type: https://arize.com/docs/ax/rest-reference/errors#resource-not-found
    RateLimitExceeded:
      description: Rate limit exceeded
      headers:
        Retry-After:
          description: |
            When throttled (429), how long to wait before retrying. Value is
            either a delta-seconds integer.
          schema:
            type: integer
            minimum: 0
          example: 42
      content:
        application/problem+json:
          schema:
            $ref: '#/components/schemas/Problem'
          example:
            status: 429
            title: Rate limit exceeded
            detail: >-
              You have exceeded the allowed number of requests. Please try again
              later.
            instance: /resource
            type: >-
              https://arize.com/docs/ax/rest-reference/errors#rate-limit-exceeded
  schemas:
    Id:
      type: string
      description: A universally unique identifier (base64-encoded opaque string).
      example: RW50aXR5OjEyMzQ1
    DeleteEvaluatorVersionsRequest:
      type: object
      description: |
        Body identifying the versions to delete from the evaluator named by the
        `evaluator_id` path parameter.
      required:
        - version_ids
      properties:
        version_ids:
          type: array
          minItems: 1
          maxItems: 100
          items:
            type: string
          description: >
            IDs of the evaluator versions to delete (up to 100 per request). IDs
            that

            do not belong to `evaluator_id` are reported as not deleted.
            Duplicate IDs

            are accepted and silently collapsed so each version is processed at
            most once.
      additionalProperties: false
    DeleteEvaluatorVersionsResponse:
      type: object
      description: >
        Result of a DELETE /v2/evaluators/{evaluator_id}/versions request.


        The delete is partial-tolerant: requested versions that exist and belong
        to

        `evaluator_id` are deleted; every requested ID that was not deleted is
        reported

        in `not_deleted_version_ids`. An ID may be not-deleted because it does
        not exist

        or belongs to a different evaluator.


        `completed` is `true` when this response is returned because the
        synchronous

        delete has fully processed the request. It does not mean every requested

        version was found and deleted: each requested ID appears in exactly one
        of

        `deleted_version_ids` or `not_deleted_version_ids`.


        The delete operation is idempotent — re-submitting already-deleted IDs
        is safe

        and simply reports them as not deleted.


        Deleting a version that is currently pinned to a running online task
        un-pins

        that task, which then falls back to resolving the evaluator's latest
        version.
      required:
        - completed
        - deleted_version_ids
        - not_deleted_version_ids
      properties:
        completed:
          type: boolean
          description: >
            Always `true` in a successful response, indicating both result lists
            are

            complete. This does not indicate whether all requested versions
            existed.
        deleted_version_ids:
          type: array
          items:
            type: string
          description: Evaluator version IDs confirmed deleted in this request.
        not_deleted_version_ids:
          type: array
          items:
            type: string
          description: Requested evaluator version IDs that were not deleted.
      additionalProperties: false
      x-forward-compatible: true
    Problem:
      type: object
      description: RFC 9457 Problem Details
      properties:
        title:
          type: string
          description: A short, human-readable summary of the problem type
        status:
          type: integer
          description: >-
            The HTTP status code generated by the origin server for this
            occurrence of the problem
        type:
          type: string
          format: uri-reference
          description: A URI reference that identifies the problem type
        detail:
          type: string
          description: >-
            A human-readable explanation specific to this occurrence of the
            problem
        instance:
          type: string
          format: uri-reference
          description: >-
            A URI reference that identifies the specific occurrence of the
            problem
      required:
        - title
        - status
      additionalProperties: false
      x-forward-compatible: true
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: <api-key>
      description: >
        Most Arize AI endpoints require authentication. For those endpoints that
        require authentication, include your API key in the request header using
        the format

        ``` Authorization: Bearer <api-key>

        ```

````