Free / open, $29/mo monitoring
HubSpot won't publish the migration map until March 2027. Here it is today.
HubSpot is retiring v1-v4 API paths and legacy apps (enforcement September 2027, v4 first on 30 March 2027) but isn't publishing per-endpoint replacement docs until March 2027. This free, open map derives the replacement today by diffing HubSpot's own public OpenAPI specs for both sides — every legacy operation, its date-based-versioning equivalent, and the exact field-level breaking differences.
Use it now (no account)
git clone https://github.com/mjaack/hubspot-dbv-map cd hubspot-dbv-map python3 scan.py /path/to/your/repo
Or browse MAP.md / map.jsondirectly in the repo, or query it through our MCP endpoint if you're working from an agent.
Weekly re-diff against your own endpoint inventory. An alert the moment a path you call changes shape.
Why this exists
On 15 September 2026, HubSpot announced end-of-support for its v1-v4 API paths and legacy apps, with the replacement (date-based versioning) already live but the per-endpoint migration guide not shipping until March 2027 — twelve months after the deadline started, six months before enforcement. Both sides of the mapping are already public in HubSpot's own OpenAPI specs, though, so this map derives it mechanically today: every legacy operation, where it lands in date-based versioning, and what changed field by field.
Frequently asked
Is this HubSpot's official migration guide?
No. HubSpot's own per-endpoint documentation isn't due until March 2027. This map is derived independently, today, by mechanically diffing HubSpot's own public OpenAPI specs for the legacy (v1-v4) and date-based-versioning (2026-03, 2026-09, ...) sides of each operation — it's a line-by-line mechanical diff, not a guess, and every finding is checkable against the source specs.
What exactly is going unsupported, and when?
v1-v3 API paths, legacy public apps and legacy private apps: unsupported starting 2026-09-15, enforced September 2027. v4 API paths: enforced 30 March 2027. Legacy private app creation already stopped for new accounts (28 September 2026) and stops for existing accounts on 26 October 2026.
What's free vs. paid?
The full map — all ~1,040 operations across 98 APIs — is free and public at github.com/mjaack/hubspot-dbv-map, as both a browsable Markdown file and machine-readable JSON. DBV Watch ($29/mo) re-diffs HubSpot's specs weekly against your own endpoint inventory and alerts you the moment something you actually call changes shape, instead of you re-checking the repo yourself.
How do I check my own codebase?
Clone the repo and run `python3 scan.py /path/to/your/repo` — it finds every HubSpot API call in your code and reports whether it's already on date-based versioning, and if not, exactly what breaks and where.
MIT licensed, source at github.com/mjaack/hubspot-dbv-map — read the diff logic before you trust it with a production migration.