---
title: "Create Variable"
method: POST
path: "/v1/projects/{project_id}/variables/"
tags: ["Projects", "Variables"]
---

# Create Variable

`POST /v1/projects/{project_id}/variables/`

## Request

- Base URL: `https://logfire-api.pydantic.dev/api`
- URL: `https://logfire-api.pydantic.dev/api/v1/projects/{project_id}/variables/`
- Auth: OAuth 2
  - Authorization code: `api/oauth/authorize`
  - Token URL: `/api/oauth/token` scopes: `project:write_variables`
- TypeScript: <https://skmtc.dev/pydantic/apis/pydantic-logfire-api/docs/v1/projects/:project_id/variables/post.ts> (a function with typed inputs; its response is checked against the schema)

Create a new variable definition, optionally with labels and versions.

Requires: User token with project:write_variables scope.

## Path parameters

- `project_id` string, uuid, required

## Request body

- VariableDefinitionCreateRequest: Request model for creating a variable definition.
  - `name` string, required
  - `description` string, nullable, required
  - `json_schema` object, nullable, required
  - `template_inputs_schema` object, nullable
  - `type_id` string, uuid, nullable
  - `rollout` RolloutData, required: Rollout configuration stored as JSONB.
    - `labels` object, required
    - `latest_weight` number
  - `overrides` OverrideData[], required
    - `name` string, nullable
    - `description` string, nullable
    - `conditions` ConditionData[], required
      - `kind` string
      - `attribute` string
      - `value` unknown
      - `values` unknown[]
        - unknown
      - `pattern` string
    - `rollout` RolloutData, required: Rollout configuration stored as JSONB.
      - `labels` object, required
      - `latest_weight` number
  - `aliases` string[]
  - `example` string, nullable
  - `external` boolean
  - `labels` object
  - `initial_serialized_value` string

## Response `201`

Successful Response

- VariableDefinitionRead: Variable definition with current labels and latest version assembled.
  - `id` string, uuid, required
  - `project_id` string, uuid, required
  - `type_id` string, uuid, nullable, required
  - `type_name` string, nullable, required
  - `kind` 'general' | 'prompt', required
  - `name` string, required
  - `display_name` string, nullable, required
  - `prompt_slug` string, nullable, required
  - `description` string, nullable, required
  - `json_schema` union, required
    - object
    - JSONBData[]
    - string
    - integer
    - boolean
    - number
  - `template_inputs_schema` union, required
    - object
    - JSONBData[]
    - string
    - integer
    - boolean
    - number
  - `labels` object, required
  - `latest_version` VersionRead, required: A version as read from the database.
    - `id` string, uuid, required
    - `variable_definition_id` string, uuid, required
    - `version` integer, required
    - `serialized_value` string, required
    - `description` string, nullable, required
    - `created_at` string, date-time, required
    - `created_by` string, uuid, nullable, required
    - `created_by_name` string, nullable, required
  - `rollout` RolloutData, required: Rollout configuration stored as JSONB.
    - `labels` object, required
    - `latest_weight` number
  - `overrides` OverrideData[], required
    - `name` string, nullable
    - `description` string, nullable
    - `conditions` ConditionData[], required
      - `kind` string
      - `attribute` string
      - `value` unknown
      - `values` unknown[]
        - unknown
      - `pattern` string
    - `rollout` RolloutData, required: Rollout configuration stored as JSONB.
      - `labels` object, required
      - `latest_weight` number
  - `aliases` string[], nullable, required
  - `example` string, nullable, required
  - `external` boolean, required
  - `created_at` string, date-time, required
  - `updated_at` string, date-time, required
  - `created_by_name` string, nullable, required
  - `updated_by_name` string, nullable, required

## Other responses

- `422`: Validation Error
- `429`: Rate limit exceeded

---

[API](https://skmtc.dev/pydantic/apis/pydantic-logfire-api.md) - [All operations](https://skmtc.dev/pydantic/apis/pydantic-logfire-api/llms.txt) - [OpenAPI document](https://skmtc.dev/pydantic/apis/pydantic-logfire-api/revisions/7996e45256f4?raw)