API Versioning
The Wefunder API is versioned by a dated header, not by the URL. URLs never change; you pin the API behavior you integrated against and upgrade deliberately.
The version header
Send the version you want on every request:
curl "https://api.wefunder.com/users/me" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
-H "Wefunder-Version: 2026-10-15"
A version is a date, YYYY-MM-DD, naming the API's behavior as of that date. The official SDKs send the header for you.
How a request's version is resolved
- The
Wefunder-Versionrequest header, when present. - Otherwise, your application's pinned version. Every application is pinned to the latest version at the moment it is created, so an integration keeps working the way it did on day one until you choose to move.
- Otherwise, the latest released version (only for requests with no application context).
An unknown or retired header value is rejected with 400 invalid_request naming the valid versions. A typo never silently falls back to something else.
Response headers
Every response tells you which version handled it and what the newest is:
| Header | Meaning |
|---|---|
Wefunder-Version | The version that produced this response |
Wefunder-Version-Latest | The newest released version |
When they differ, a newer version is available. Read the changelog for what changed before you move your pin.
Released versions
| Version | Released | Status |
|---|---|---|
2026-10-15 | 2026-10-15 | Current. Removes GET /activity and the syndicate deal close and finalize endpoints; see the changelog. |
2026-10-01 | 2026-10-01 | Supported. Applications created before 2026-10-15 are pinned here and keep its behavior until they move their pin. |
2025-01-15 appeared in pre-release documentation and early SDK builds before any version was resolved by the API. It is accepted as an alias for 2026-10-01 during the launch period and will be removed; do not pin new integrations to it.
What changes between versions
Non-breaking changes ship to every version immediately and never require a new date: new endpoints, new optional parameters, new response fields, new enum values, higher rate limits, bug fixes.
Breaking changes get a new dated version: removing or renaming a field or endpoint, changing a field's type, adding a required parameter, changing an error shape, changing a default. Your pinned version keeps its existing behavior.
Operations marked beta in the reference may still change shape between releases; the changelog announces each such change.
Retiring a version
No released version has been retired. Wefunder has not yet published a support window or retirement timeline for dated versions; the deprecation policy says what is defined today. A version that stops being served is announced in the changelog.