---
title: "Anthropic Cache diagnostics is out of beta: 2026-09-23 | Harbyn"
description: "Anthropic Cache diagnostics is out of beta, announced Sep 23, 2026."
canonical: "https://harbyn.com/changes/anthropic/2026-09-23-cache-diagnostics-is-out-of-beta"
last-updated: 2026-09-24
---

# Anthropic Cache diagnostics is out of beta

Markdown version of <https://harbyn.com/changes/anthropic/2026-09-23-cache-diagnostics-is-out-of-beta>.

Behavior change - Anthropic. low severity. Announced.

Cache diagnostics is out of beta on the Claude API and no longer requires the cache-diagnosis-2026-04-07 beta header. Requests that still send the header work as before. Responses from POST /v1/messages now always include the diagnostics field, which is null when the request did not include the diagnostics object.

## Facts

| Fact | Value |
| --- | --- |
| Vendor | [Anthropic](https://harbyn.com/vendors/anthropic.md) |
| Kind | Behavior change |
| Severity | low |
| Status | Announced |
| Announced | Sep 23, 2026 |
| Added to Harbyn | Sep 24, 2026 |
| Lead time | No dated deadline |
| Symbols | `cache-diagnosis-2026-04-07`, `diagnostics` |
| Review | Automated, extracted by a model |

## Find it in your code

```sh
npx harbyn scan
```

This change names no identifier the scanner can match line by line, so the scan tells you whether your repository uses Anthropic, from its packages and API hosts. Nothing leaves your machine.

## Sources

Where this event comes from: the page we read, when we read it, and the hash of that snapshot.

- <https://platform.claude.com/docs/en/release-notes/overview.md> (changelog, fetched 2026-09-24 17:16 UTC, sha256 `62f890350b58e6da475adcc09e72e9a16dbad42f99c96e39f3d2543575c3423c`)

## Related changes

### More from Anthropic

- [Compliance Activity Feed no longer returns names or titles](https://harbyn.com/changes/anthropic/2026-09-24-compliance-activity-feed-no-longer-returns-names-or-titles.md) (Behavior change, announced Sep 24, 2026)
- [Claude Sonnet 5.5 rejects five Claude Sonnet 5 request patterns](https://harbyn.com/changes/anthropic/2026-09-28-claude-sonnet-5-5-changes-compatibility-with-claude-sonnet-5-code.md) (Behavior change, announced Sep 28, 2026)
- [Claude Sonnet 4.5 model: retirement on 2026-11-30](https://harbyn.com/changes/anthropic/2026-09-30-claude-sonnet-4-5-model-retirement.md) (Retirement, effective Nov 30, 2026)
- [Fingerprint storage requires the diagnostics object](https://harbyn.com/changes/anthropic/2026-09-09-fingerprint-storage-requires-the-diagnostics-object.md) (Behavior change, announced Sep 9, 2026)

### Changes at other vendors

- [Amazon Selling Partner API: ORDER\_CHANGE notifications add PreFulfillmentStatusChange for Amazon Autos](https://harbyn.com/changes/amazon-sp-api/2026-10-14-sp-api-updates-new-listings-items-api-ivp-values-in-eu5-jp-and-ca-stores-oct-3.md) (effective Oct 28, 2026)
- [BigCommerce: 301 redirects will apply only to storefront channels](https://harbyn.com/changes/bigcommerce/2026-10-07-301-redirects-now-apply-to-storefront-channels-only.md) (effective Nov 10, 2026)
- [GitHub: Secret scanning audit log business field changes to enterprise slug](https://harbyn.com/changes/github/2026-10-20-updates-to-github-secret-scanning-7.md) (effective Nov 12, 2026)
- [Jira / Atlassian Cloud: New IP address ranges in use from January 1, 2027](https://harbyn.com/changes/atlassian-jira/2026-10-16-atlassian-cloud-adds-new-ip-address-ranges.md) (effective Jan 1, 2027)

[All upcoming deadlines](https://harbyn.com/deadlines.md)