API sunsets · HubSpot · checked

HubSpot API v4 end of support on 30 March 2027

HubSpot API v4 loses support on 30 March 2027. After it, v4 endpoints get no more fixes and may degrade or stop without notice; and Marketplace apps on v4 can be denied certification or removed. Nothing fails on the day, so the change is silent: calls keep working, with no fixes and no guarantee. HubSpot names 2026-09 as the replacement (the v4 notice (21 May 2026) named 2026-03; HubSpot's migration guide now names 2026-09, the latest). Record your real calls on v4 before the date and replay them on 2026-09: after it, v4 can change or stop without notice. Find every place your code pins v4: npx --allow-git=root github:agentwares/api-sunset scan

$ npx --allow-git=root github:agentwares/api-sunset scan

npx --allow-git=root github:agentwares/api-sunset scan lists every API version your code and config pin (Shopify, Meta Graph, Google Ads, HubSpot, Stripe and the rest of this list) with its end date, what breaks and this page's link. It needs no account and no API key, reads your files on your machine and sends nothing; its one request fetches this data. Free and MIT licensed.

The facts

API
HubSpot APICovers endpoints with a numbered version in the path.
Version
v4
Announced
21 May 2026
Ends
30 March 2027
After the date
unsupported
Silent?
Yes: no error is returned
Replacement
2026-09the v4 notice (21 May 2026) named 2026-03; HubSpot's migration guide now names 2026-09, the latest

What breaks after 30 Mar 2027

How to upgrade

  1. Find every place your code and config pin v4: npx --allow-git=root github:agentwares/api-sunset scan prints each file and line, and the variable name for a .env file, never its value.
  2. Read what changed between v4 and 2026-09 in HubSpot's notes, and list the calls that touch it.
  3. Before 30 March 2027, send your real calls to v4 and to 2026-09 and compare the answers: same status, same fields, same values where they should match; after it, v4 can change or stop without notice.
  4. Change the version string, deploy, and watch the first day's responses.

Record your real calls on the old version before the date, and replay them on the new one.

agentcheck runs scheduled checks of an endpoint. A check sends the request you define (a path or a full URL, a method and a body, with your API key as a header, stored encrypted) on a schedule and compares each response with a golden: exact text, contains, a regular expression or a JSON Schema, none of which costs an LLM call. When a response stops matching, it opens an incident and alerts you. Point one check at v4 and one at 2026-09 with the same golden, and you see which of your calls answer differently before 30 March 2027.

Free: 1 monitored target, hourly checks, badge and public status page. Starter: 3 targets, 5-minute checks, Slack and Discord alerts, 30-day history. Recording the calls your code already makes is a different path: the trace import (POST /api/v1/targets/{id}/traces, or the agentcheck_record MCP tool) takes agent traces, a prompt and an answer, and turns them into checks judged by the LLM judge (Pro). It does not take raw HTTP requests and responses, so for an API the scheduled checks are the way in today.

Migration watch is not built. It would record the calls your code makes to HubSpot API v4 and replay them on 2026-09 until 30 March 2027, with nothing to set up, and email you what answers differently. If you would pay for that, say so with one click. The click is counted; nothing else is sent or stored.

Other HubSpot dates

Every API sunset, by date

Sources

Built only from HubSpot's own pages. No intent is implied: a date is what the page says on the day it was read. Data: /apis/sunsets.json.

api-sunset is a free tool from agentcheck, which runs scheduled checks of your endpoints and alerts you when an answer changes.