---
title: "Langfuse Python SDK v5 and JS/TS SDK v6 remove deprecated APIs: 2026-10-14 | Harbyn"
description: "Langfuse Python SDK v5 and JS/TS SDK v6 remove deprecated APIs, announced Oct 14, 2026."
canonical: "https://harbyn.com/changes/langfuse/2026-10-14-new-sdk-majors-for-langfuse-v4"
last-updated: 2026-10-25
---

# Langfuse Python SDK v5 and JS/TS SDK v6 remove deprecated APIs

Markdown version of <https://harbyn.com/changes/langfuse/2026-10-14-new-sdk-majors-for-langfuse-v4>.

Breaking change - Langfuse. medium severity. In effect.

The new SDK majors remove api.legacy and api.ingestion and replace scores\_v3/scoresV3 with api.scores. They require Langfuse Cloud or self-hosted v4.59.0+, and Python 3.11+ or Node.js 22+. They also add experiment links, nested metadata filters and compressed span export.

## Facts

| Fact | Value |
| --- | --- |
| Vendor | [Langfuse](https://harbyn.com/vendors/langfuse.md) |
| Kind | Breaking change |
| Severity | medium |
| Status | In effect |
| Announced | Oct 14, 2026 |
| Added to Harbyn | Oct 25, 2026 |
| Lead time | No dated deadline |
| Review | Reviewed by a person, 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 Langfuse, 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://langfuse.com/changelog> (changelog, fetched 2026-10-21 14:31 UTC, sha256 `9e7ae68f95befd1f31aec85e7c2ef9351a653cb151bf1ede17b3b296f6642b61`)

## Related changes

### Changes at other vendors

- [Amazon Selling Partner API: October listing attribute usage and enumeration value updates](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-2.md) (effective Oct 26, 2026)
- [Supabase: four CBC-mode TLS 1.2 cipher suites will be removed from project HTTP APIs](https://harbyn.com/changes/supabase/2026-10-12-an-outdated-subset-of-tls-1-2-ciphers-will-be-disabled-on-project-http-apis.md) (effective Nov 10, 2026)
- [Google Workspace APIs: OAuth clients must be marked as agentic to call Google Workspace MCP servers](https://harbyn.com/changes/google-workspace/2026-10-12-oauth-clients-must-be-marked-as-agentic-to-call-google-workspace-mcp-servers.md) (effective Nov 11, 2026)
- [Bitbucket Cloud API: Git Credential Manager upgrade required for OAuth 2.0 Git authentication](https://harbyn.com/changes/bitbucket/2026-10-13-git-credential-manager-upgrade-required-for-oauth-2-0-git-authentication.md) (effective Nov 30, 2026)

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