> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.withverifa.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.withverifa.com/_mcp/server.

# Versioning

> API versioning and response key formatting.

Verifa uses date-based API versioning. Each version is identified by a release
date (e.g. `2026-02-01`).

## Setting the version

Pass the `Verifa-Version` header to pin your request to a specific API version:

```bash
curl https://api.withverifa.com/api/v1/sessions \
  -H "X-API-Key: vk_live_your_key_here" \
  -H "Verifa-Version: 2026-01-01"
```

If the header is omitted, the version pinned to your API key at creation time is
used. This ensures your integration stays stable even as new versions are
released.

## Version lifecycle

* **Active** — Fully supported, receives bug fixes.
* **Deprecated** — Still functional but no longer receives updates. Migrate to a
  newer version.
* **Retired** — Requests return `400` with an upgrade message.

We provide at least 12 months notice before retiring an API version.

## Current version

The current API version is `2026-01-01`.

## Related

* [Key Inflection](/api-details/key-inflection) — Control response JSON key casing
* [Errors](/api-details/errors) — Error codes including version-related 400 responses
* [Authentication](/api-details/authentication) — API key setup and version pinning