---
title: "API versions"
description: "The API version is a date in a header. A breaking change ships as a new version with a changelog entry, and an old version keeps working at least twelve months after the next one ships."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.overlane.app/llms.txt
> Use this file to discover all available pages before exploring further.

# API versions

The API version is a date. Send it in the `Overlane-Version` header, or leave the header off for the current version. See [REST API](/developers/rest-api/).

```sh
overlane api versions
```

## The rule

- A **breaking change** (a removed or renamed field, a changed meaning, a removed route) ships only as a new version, with an entry in the changelog that lists exactly what broke.
- A change that only adds (a new route, a new optional field, a new event type) does not need a new version.
- When a version is replaced, it keeps working for **at least twelve months** after the next version's release date. Its end date is published here and in `overlane api versions`.
- A snapshot of the OpenAPI document is kept for every version, so you can read exactly what you built against.

## Versions

| Version | Released | Supported until | What it is |
| --- | --- | --- | --- |
| 2026-10-10 | 2026-10-10 | the newest version | First dated version: connectors, API keys, outbound webhooks, rate limit headers and the generated OpenAPI document |

```js run
assert.equal(API_CHANGELOG.at(-1).version, CURRENT_API_VERSION);
assert.equal(changelogProblems(API_CHANGELOG).length, 0);
// A version replaced after only four months fails the twelve month rule.
const soon = [
  { version: "2026-10-10", releasedAt: "2026-10-10", supportedUntil: "2027-02-01", breaking: [], summary: "a" },
  { version: "2026-11-01", releasedAt: "2026-11-01", supportedUntil: null, breaking: ["renamed a field"], summary: "b" },
];
assert.equal(changelogProblems(soon).length, 1);
assert.equal(MIN_SUPPORT_MONTHS, 12);
```

The changelog is data in the contracts, and the rule above is a function over it that a test runs, so a version cannot be retired early by editing a date.

Source: https://docs.overlane.app/developers/versions/index.mdx