> ## 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.

# Resolve a label to a prompt version

> Resolve a label on a prompt to the version it points to. Returns the
full `PromptVersion` object that this label currently references.

<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 get /v2/prompts/{prompt_id}/labels/{label_name}
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: 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: 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: 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: Users
    description: >
      Users represent members of an account. The Users endpoints allow creating,

      listing, updating (display name), and removing users from the account
      programmatically.
paths:
  /v2/prompts/{prompt_id}/labels/{label_name}:
    get:
      tags:
        - Prompts
      summary: Resolve a label to a prompt version
      description: >
        Resolve a label on a prompt to the version it points to. Returns the

        full `PromptVersion` object that this label currently references.


        <Note>This endpoint is in beta, read more
        [here](https://arize.com/docs/ax/rest-reference#api-version-stages).</Note>
      operationId: prompt_labels_get
      parameters:
        - $ref: '#/components/parameters/PromptIdPathParam'
        - $ref: '#/components/parameters/LabelNamePathParam'
      responses:
        '200':
          $ref: '#/components/responses/PromptVersion'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '429':
          $ref: '#/components/responses/RateLimitExceeded'
components:
  parameters:
    PromptIdPathParam:
      name: prompt_id
      in: path
      description: The unique prompt identifier (base64)
      required: true
      schema:
        $ref: '#/components/schemas/Id'
      example: UHJvbXB0OjEyMzQ1
    LabelNamePathParam:
      name: label_name
      in: path
      description: The name of the label (e.g., "production", "staging")
      required: true
      schema:
        type: string
  responses:
    PromptVersion:
      description: A prompt version object
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/PromptVersion'
          example:
            id: pv_001
            prompt_id: prompt_001
            commit_hash: abc123def456
            commit_message: Updated system prompt
            messages:
              - role: system
                content: You are a helpful assistant.
              - role: user
                content: Hello, {name}!
            input_variable_format: f_string
            provider: open_ai
            model: gpt-4
            invocation_params:
              temperature: 0.7
              max_tokens: 1000
            provider_params: {}
            created_at: '2024-01-02T12:00:00Z'
            created_by_user_id: user_12345
    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
    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
    PromptVersion:
      type: object
      required:
        - id
        - prompt_id
        - commit_hash
        - commit_message
        - messages
        - input_variable_format
        - provider
        - model
        - created_at
        - created_by_user_id
      properties:
        id:
          type: string
          description: The prompt version ID
        prompt_id:
          type: string
          description: The prompt ID this version belongs to
        commit_hash:
          type: string
          description: The commit hash of this version
        commit_message:
          type: string
          description: The commit message describing the changes in this version
        messages:
          type: array
          description: The messages that make up the prompt template
          items:
            $ref: '#/components/schemas/LLMMessage'
        input_variable_format:
          $ref: '#/components/schemas/InputVariableFormat'
        provider:
          $ref: '#/components/schemas/LlmProvider'
        model:
          type: string
          description: The model to use for the call
        invocation_params:
          allOf:
            - $ref: '#/components/schemas/InvocationParams'
          description: >-
            LLM invocation parameters for this version. When absent, no
            invocation parameters were set on this version.
        provider_params:
          allOf:
            - $ref: '#/components/schemas/ProviderParams'
          description: >-
            Provider-specific parameters for this version. When absent, no
            provider-specific parameters were set on this version.
        created_at:
          type: string
          format: date-time
          description: When the version was created
        created_by_user_id:
          type: string
          description: The user ID of the user who created this version
        labels:
          type: array
          items:
            type: string
          description: >-
            Label names currently pointing to this version (e.g., "production",
            "staging"). Labels are case-sensitive.
      description: >
        A prompt version represents a specific snapshot of a prompt's
        configuration.

        Each version captures the messages, model settings, and parameters at a
        point

        in time. Versions are immutable once created and are identified by a
        commit hash.
      additionalProperties: false
    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
    LLMMessage:
      type: object
      description: A message in the prompt template
      required:
        - role
      properties:
        role:
          $ref: '#/components/schemas/MessageRole'
        content:
          type: string
          nullable: true
          description: The content of the message
        tool_call_id:
          type: string
          description: The ID of the tool call this message is responding to
        tool_calls:
          type: array
          description: Tool calls generated by the model
          items:
            $ref: '#/components/schemas/ToolCall'
    InputVariableFormat:
      type: string
      enum:
        - f_string
        - mustache
        - none
      description: >
        The format for input variables in the prompt messages. Defaults to
        `f_string` if not provided.

        - `f_string`: Single curly braces ({variable_name})

        - `mustache`: Double curly braces ({{variable_name}})

        - `none`: **Deprecated.** Treated as `f_string`. Will be removed in a
        future version.
    LlmProvider:
      type: string
      enum:
        - open_ai
        - azure_open_ai
        - aws_bedrock
        - vertex_ai
        - anthropic
        - custom
      description: The LLM provider to use
    InvocationParams:
      type: object
      description: Parameters for the LLM invocation
      properties:
        temperature:
          type: number
          description: Sampling temperature (higher = more random)
        max_tokens:
          type: integer
          description: Maximum number of tokens to generate
        max_completion_tokens:
          type: integer
          description: Maximum number of completion tokens to generate
        top_p:
          type: number
          description: Nucleus sampling parameter
        frequency_penalty:
          type: number
          description: Frequency penalty (-2.0 to 2.0)
        presence_penalty:
          type: number
          description: Presence penalty (-2.0 to 2.0)
        stop:
          type: array
          items:
            type: string
          description: Stop sequences
        response_format:
          allOf:
            - $ref: '#/components/schemas/ResponseFormat'
          description: >-
            Response format configuration. Optional. When omitted, no structured
            output constraint is applied (the provider's default plain-text
            behavior is used).
        tool_config:
          allOf:
            - $ref: '#/components/schemas/ToolConfig'
          description: >-
            Tool configuration for the LLM invocation. Optional. When omitted,
            no tools are made available to the model.
        top_k:
          type: integer
          description: >-
            Top-K sampling parameter. A top-K of 1 means the next selected token
            is the most probable (greedy decoding).
        thinking_level:
          type: string
          description: >-
            Controls how much reasoning the model performs before responding.
            Supported by Gemini 3.x models. Accepted values: 'low', 'high'.
        thinking_budget:
          type: integer
          description: >-
            Maximum tokens the model may use for internal reasoning. Supported
            by Gemini 2.5 models. Range: 0-24576 (Flash/Flash-Lite) or 128-32768
            (Pro). Set 0 to disable thinking on Flash models.
        reasoning_effort:
          type: string
          description: >-
            Controls how much reasoning the model performs before responding.
            Supported by OpenAI o-series and GPT-5 models. o-series: 'low' |
            'medium' | 'high'. GPT-5: 'none' | 'low' | 'medium' | 'high' |
            'xhigh'.
        verbosity:
          type: string
          description: >-
            Controls the verbosity of model output. Supported by OpenAI GPT-5
            series. Accepted values: 'low' | 'medium' | 'high'.
      additionalProperties: true
    ProviderParams:
      type: object
      description: Provider-specific parameters
      properties:
        azure_params:
          type: object
          description: Azure OpenAI specific parameters
          properties:
            azure_deployment_name:
              type: string
              description: The Azure deployment name
            azure_openai_endpoint:
              type: string
              description: The Azure OpenAI endpoint URL
            azure_openai_version:
              type: string
              description: The Azure OpenAI API version
        anthropic_headers:
          type: object
          description: Anthropic-specific headers
          properties:
            anthropic_beta:
              type: array
              description: Anthropic beta feature flags
              items:
                type: string
                nullable: true
              nullable: true
        anthropic_version:
          type: string
          description: Anthropic API version
        bedrock_options:
          type: object
          description: AWS Bedrock options
          properties:
            use_converse_endpoint:
              type: boolean
              default: false
              description: >-
                Whether to use the AWS Bedrock Converse endpoint. Defaults to
                `false`.
        region:
          type: string
          description: Region for the model deployment
      additionalProperties: true
    MessageRole:
      type: string
      enum:
        - user
        - assistant
        - system
        - tool
      description: The role of the message author
    ToolCall:
      type: object
      description: A tool call generated by the model
      required:
        - type
        - function
      properties:
        id:
          type: string
          description: The ID of the tool call
        type:
          $ref: '#/components/schemas/ToolCallType'
        function:
          $ref: '#/components/schemas/ToolCallFunction'
    ResponseFormat:
      type: object
      description: Response format configuration
      properties:
        type:
          allOf:
            - $ref: '#/components/schemas/ResponseFormatType'
          default: text
          description: The response format type. Defaults to `text` if not specified.
        json_schema:
          type: object
          description: JSON schema configuration (when type is json_schema)
          properties:
            name:
              type: string
              description: The name of the JSON schema
            description:
              type: string
              description: A description of the JSON schema
            schema:
              type: object
              description: The JSON schema object
            strict:
              type: boolean
              default: false
              description: >-
                Whether to enforce strict schema validation. Defaults to
                `false`.
    ToolConfig:
      type: object
      description: Tool configuration for the LLM invocation
      properties:
        tools:
          type: array
          description: List of tool definitions available to the model
          items:
            type: object
        tool_choice:
          description: Tool choice configuration
    ToolCallType:
      type: string
      enum:
        - function
      description: The type of tool call
    ToolCallFunction:
      type: object
      description: The function to call
      required:
        - name
        - arguments
      properties:
        name:
          type: string
          description: The name of the function
        arguments:
          type: string
          description: The arguments to the function as a JSON string
    ResponseFormatType:
      type: string
      enum:
        - text
        - json_object
        - json_schema
      description: The response format type
  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>

        ```

````