---
title: "Create or replace a budget's custom forecast"
method: PUT
path: "/api/v2/cost/budget/custom-forecast"
tags: ["Cloud Cost Management"]
---

# Create or replace a budget's custom forecast

`PUT /api/v2/cost/budget/custom-forecast`

Create or replace the custom forecast for an existing budget.
Pass an empty `entries` list to delete the custom forecast for the budget.

## Request body

- CustomForecastUpsertRequest — Request body to upsert (create or replace) the custom forecast for a budget.
  - `data` CustomForecastUpsertRequestData, required — Custom forecast resource wrapper in an upsert request.
    - `attributes` CustomForecastUpsertRequestDataAttributes, required — Attributes of a custom forecast upsert request.
      - `budget_uid` string, required — The UUID of the budget that this custom forecast belongs to.
      - `entries` CustomForecastEntry[], required — Monthly custom forecast entries. An empty list deletes any existing custom forecast for the budget.
        - `amount` number, double, required — Forecast amount for the month.
        - `month` integer, required — Month the custom forecast entry applies to, in `YYYYMM` format.
        - `tag_filters` CustomForecastEntryTagFilter[], required — Tag filters that scope this custom forecast entry to specific resources.
          - `tag_key` string, required — The tag key to filter on.
          - `tag_value` string, required — The tag value to filter on.
    - `id` string — Unused on upsert; the resource is keyed by `budget_uid`. Send an empty string.
    - `type` 'custom_forecast', required — The type of the custom forecast resource. Must be `custom_forecast`.

## Response `200`

OK

- CustomForecastResponse — Response object containing the custom forecast for a budget.
  - `data` CustomForecastResponseData, required — Custom forecast resource wrapper in a response.
    - `attributes` CustomForecastResponseDataAttributes, required — Attributes of a custom forecast.
      - `budget_uid` string, required — The UUID of the budget that this custom forecast belongs to.
      - `created_at` integer, required — Timestamp the custom forecast was created, in Unix milliseconds.
      - `created_by` string, required — The id of the user that created the custom forecast.
      - `entries` CustomForecastEntry[], required — Monthly custom forecast entries.
        - `amount` number, double, required — Forecast amount for the month.
        - `month` integer, required — Month the custom forecast entry applies to, in `YYYYMM` format.
        - `tag_filters` CustomForecastEntryTagFilter[], required — Tag filters that scope this custom forecast entry to specific resources.
          - `tag_key` string, required — The tag key to filter on.
          - `tag_value` string, required — The tag value to filter on.
      - `updated_at` integer, required — Timestamp the custom forecast was last updated, in Unix milliseconds.
      - `updated_by` string, required — The id of the user that last updated the custom forecast.
    - `id` string, required — The unique identifier of the custom forecast.
    - `type` 'custom_forecast', required — The type of the custom forecast resource. Must be `custom_forecast`.

## Other responses

- `400` — Bad Request
- `404` — Not Found
- `429` — Too many requests

---

[API](https://skmtc.net/datadog/apis/api-v2.md) · [All operations](https://skmtc.net/datadog/apis/api-v2/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/datadog/api-v2/revisions/da68bf029e4c/schema)