---
title: "Resolve a label to a prompt version"
method: GET
path: "/v2/prompts/{prompt_id}/labels/{label_name}"
tags: ["Prompts"]
---

# Resolve a label to a prompt version

`GET /v2/prompts/{prompt_id}/labels/{label_name}`

## Request

- Base URL: `https://api.arize.com`
- URL: `https://api.arize.com/v2/prompts/{prompt_id}/labels/{label_name}`
- Auth: HTTP bearer

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>

## Path parameters

- `prompt_id` string, required: A universally unique identifier (base64-encoded opaque string).
- `label_name` string, required

## Response `200`

A prompt version object

- PromptVersion: 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.
  - `id` string, required: The prompt version ID
  - `prompt_id` string, required: The prompt ID this version belongs to
  - `commit_hash` string, required: The commit hash of this version
  - `commit_message` string, required: The commit message describing the changes in this version
  - `messages` LLMMessage[], required: The messages that make up the prompt template
    - `role` 'USER' | 'ASSISTANT' | 'SYSTEM' | 'TOOL', required: The role of the message author
    - `content` string, nullable: The content of the message
    - `tool_call_id` string: The ID of the tool call this message is responding to
    - `tool_calls` ToolCall[]: Tool calls generated by the model
      - `id` string: The ID of the tool call
      - `type` 'FUNCTION', required: The type of tool call
      - `function` ToolCallFunction, required: The function to call
        - `name` string, required: The name of the function
        - `arguments` string, required: The arguments to the function as a JSON string
  - `input_variable_format` 'F_STRING' | 'MUSTACHE' | 'NONE', required: 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.
  - `provider` 'OPEN_AI' | 'AZURE_OPEN_AI' | 'AWS_BEDROCK' | 'VERTEX_AI' | 'ANTHROPIC' | 'CUSTOM', required: The LLM provider to use
  - `model` string, required: The model to use for the call
  - `invocation_params` InvocationParams: Parameters for the LLM invocation
    - `temperature` number: Sampling temperature (higher = more random)
    - `max_tokens` integer: Maximum number of tokens to generate
    - `max_completion_tokens` integer: Maximum number of completion tokens to generate
    - `top_p` number: Nucleus sampling parameter
    - `frequency_penalty` number: Frequency penalty (-2.0 to 2.0)
    - `presence_penalty` number: Presence penalty (-2.0 to 2.0)
    - `stop` string[]: Stop sequences
    - `response_format` ResponseFormat: Response format configuration
      - `type` 'TEXT' | 'JSON_OBJECT' | 'JSON_SCHEMA': The response format type
      - `json_schema` JsonSchemaConfig: JSON schema configuration (when type is JSON_SCHEMA)
        - `name` string: The name of the JSON schema
        - `description` string: A description of the JSON schema
        - `schema` object: The JSON schema object
        - `strict` boolean: Whether to enforce strict schema validation. Defaults to `false`.
    - `tool_config` ToolConfig: Tool configuration for the LLM invocation
      - `tools` ToolDefinition[]: List of tool definitions available to the model
      - `tool_choice` unknown
    - `top_k` integer: Top-K sampling parameter. A top-K of 1 means the next selected token is the most probable (greedy decoding).
    - `thinking_level` string: Controls how much reasoning the model performs before responding. Supported by Gemini 3.x models. Accepted values: 'low', 'high'.
    - `thinking_budget` integer: 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` string: 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` string: Controls the verbosity of model output. Supported by OpenAI GPT-5 series. Accepted values: 'low' | 'medium' | 'high'.
    - `service_tier` string: Processing tier for the request. Supported by OpenAI only, and only for models eligible for Priority processing. Accepted value: 'priority'. Omit to use the project default.
  - `provider_params` ProviderParams: Provider-specific parameters
    - `azure_params` AzureParams: Azure OpenAI specific parameters
      - `azure_deployment_name` string: The Azure deployment name
      - `azure_openai_endpoint` string: The Azure OpenAI endpoint URL
      - `azure_openai_version` string: The Azure OpenAI API version
    - `anthropic_headers` AnthropicHeaders: Anthropic-specific headers
      - `anthropic_beta` string[], nullable: Anthropic beta feature flags
    - `anthropic_version` string: Anthropic API version
    - `bedrock_options` BedrockOptions: AWS Bedrock options
      - `use_converse_endpoint` boolean: Whether to use the AWS Bedrock Converse endpoint. Defaults to `false`.
    - `region` string: Region for the model deployment
  - `created_at` string, date-time, required: When the version was created
  - `created_by_user_id` string, required: The user ID of the user who created this version
  - `labels` string[]: Label names currently pointing to this version (e.g., "production", "staging"). Labels are case-sensitive.

## Other responses

- `400`: Invalid request
- `401`: Authentication is required
- `404`: Not found
- `429`: Rate limit exceeded

## Changes

> 48 revisions in range; 1 not diffed.

- **2026-08-27** `9263b98aaefb`: 1 info
  - added the optional property `invocation_params/allOf[#/components/schemas/InvocationParams]/service_tier` to the response with the `200` status
- **2026-08-06** `4f94eb2fd1ab`: 2 breaking, 30 warning, 17 info
  - the `invocation_params` response's property type changed from `object` to no type for status `200`
  - the `provider_params` response's property type changed from `object` to no type for status `200`
  - removed the optional property `invocation_params/frequency_penalty` from the response with the `200` status
  - removed the optional property `invocation_params/max_completion_tokens` from the response with the `200` status
  - …45 more

[Operation history](https://skmtc.dev/arize-ai/apis/arize-rest-api/changes/v2/prompts/:prompt_id/labels/:label_name/get.md)

---

[API](https://skmtc.dev/arize-ai/apis/arize-rest-api.md) - [All operations](https://skmtc.dev/arize-ai/apis/arize-rest-api/llms.txt) - [OpenAPI document](https://skmtc.dev/arize-ai/apis/arize-rest-api/revisions/22ad4acd3cbb?raw)