# Versions and compatibility

Every pinned source revision, what it applies to, and how the baselines relate to each other.

Page ID: releases/versions
Applicability: universe-implementation
Authority: universe-implementation
Networks: mainnet
Verified: 2026-08-31
Locale: en
URL: https://bitcoinuniverseio.github.io/atomicals-and-arc-20/releases/versions/

---
## The verified source set

## Every pinned source

## The two baselines

The protocol baseline is preserved as history. The Universe revisions move. Rewriting the
historical baseline whenever a service upgrades would erase the record of what a transaction meant
when it was made.

**Protocol reference baseline.** Atomicals ElectrumX v1.5.2.0, commit `8df23747`, released
2025-03-27. Every version-sensitive protocol statement on this site is pinned to it. It is not
silently updated.

**Universe implementation revisions.** Listed separately, per page, in each source panel. They move
with deployments.

A page that describes both says which is which.

## Documentation versions

| Version | Status | Covers |
| --- | --- | --- |
| 2026.08 | Current | The full platform: protocol, guides, contracts, tools, and machine readable outputs |

Earlier documentation existed as a small set of standalone files. Those routes are preserved as
compatibility artefacts and are regenerated from this content, so they cannot drift.
See [deprecations](/releases/deprecations/).

## Compatibility matrix

| Consumer | Requires | Notes |
| --- | --- | --- |
| Universe NFT and Realm index | Provider version, tag, commit, and the exact AIP set `[1, 3]` | Refuses a provider that does not match |
| Universe ARC-20 index | The pinned Atomicals proxy contract | Declares partial coverage with an explicit reason |
| Marketplace v1 | A release SHA identifying the exact deployed indexer commit | Binds the settlement authority identity per protocol lane |
| Generated TypeScript client | An OpenAPI document version | Regenerate rather than hand editing |
| Documentation MCP server | Built site artefacts | Works offline once installed |

## Pinning your own integration

1. Choose a validator revision or release, and record it.
2. Record the network and its active rule set.
3. Record the Universe service revision from `GET /version`.
4. Re-run the [conformance vectors](/reference/conformance/) against that combination.
5. Re-check before every upgrade, not after.