---
title: Cloudflare Deprecates the foundation_dns DNS Setting
description: Cloudflare removes the foundation_dns boolean from DNS settings endpoints on 2026-11-23. Automation toggling it needs to find the replacement before then.
date: 2026-08-06T00:00:00.000Z
category: data-automation
tags: cloudflare, dns, api, deprecation
---

## Quick Answer

Cloudflare deprecates the `foundation_dns` boolean in the DNS settings endpoints for both zone settings and account defaults (`/zones/{zone_id}/dns_settings` and `/accounts/{account_id}/dns_settings`). It stops being honored on 2026-11-23. Automation reading or toggling this field needs to check the current DNS settings API reference for its replacement before that date, since the exact field name Cloudflare intends as the successor isn't specified in the changelog entry itself.

## What's actually changing

[Cloudflare's changelog](https://developers.cloudflare.com/fundamentals/api/reference/deprecations/) states the change directly:

> "The `foundation_dns` boolean is deprecated in the DNS settings endpoints for zone settings and account defaults"

Foundation DNS itself, Cloudflare's enterprise-grade authoritative DNS offering enabled via `"foundation_dns": true` on the DNS settings endpoint, isn't described as being discontinued. What's deprecated is specifically this boolean field on the [`/zones/{zone_id}/dns_settings` and `/accounts/{account_id}/dns_settings`](https://developers.cloudflare.com/api/resources/dns/subresources/settings/) endpoints, published and made effective the same day, 2026-07-27, with a longer runway before removal, 2026-11-23.

<Callout type="warning" title="Don't guess the replacement field name">
  Cloudflare's own changelog entry for this specific deprecation doesn't name an
  exact successor field. Rather than assume a plausible-sounding replacement,
  pull the current DNS settings API reference directly before updating
  automation, and confirm the field name against a real API response, not a
  guess.
</Callout>

## Structural Comparison Matrix

| Operational Aspect         | Before 2026-11-23                                                      | After 2026-11-23                           |
| :------------------------- | :--------------------------------------------------------------------- | :----------------------------------------- |
| **`foundation_dns` field** | Read/write, controls Foundation DNS state                              | No longer honored                          |
| **Endpoints affected**     | `/zones/{zone_id}/dns_settings`, `/accounts/{account_id}/dns_settings` | Same endpoints, different accepted fields  |
| **Foundation DNS itself**  | Available                                                              | Still available, through a different field |

## Fix it: audit before the field goes silent

The real risk here isn't a thrown error. A script that `PATCH`es `foundation_dns` and checks only the HTTP status code, not the actual resulting DNS settings state, may keep reporting success on a field the API silently stops honoring, while Foundation DNS quietly stops being toggled the way the automation expects.

```bash title="check what a DNS settings call currently returns"
curl -X GET \
  "https://api.cloudflare.com/client/v4/zones/<zone_id>/dns_settings" \
  -H "Authorization: Bearer <api_token>"
```

```bash title="find every call site to review before 2026-11-23"
grep -rn "foundation_dns" --include="*.tf" --include="*.sh" --include="*.mjs" .
```

Run the audit now, confirm the current API response shape against the live DNS settings docs, and update automation to match, rather than waiting for a silent no-op to surface as a support ticket in November.

## Confirmed version

Sourced from Cloudflare's official changelog, published 2026-07-27, deprecation effective the same day, end of life 2026-11-23. The exact replacement field name wasn't found in this deprecation's own changelog text; verify against the live DNS settings API reference before updating automation. Browse more posts like this in the [Data Automation](/data-automation) archive.