Architecture overview

Where every Atomicals answer comes from. Universe-operated Bitcoin Core produces blocks. Atomicals ElectrumX reads them and applies the protocol rules, which is where protocol interpretation happens. A Universe index scans that provider and publishes an immutable generation as a materialised read model. Products read the index through a public API. Each hop can be behind the one before it, so every answer carries the generation identifier and indexed height it was computed at. No third-party blockchain data provider sits in any production path.

Where every Atomicals answer comes from

Universe-operated Bitcoin Core produces blocks. Atomicals ElectrumX reads them and applies the protocol rules, which is where protocol interpretation happens. A Universe index scans that provider and publishes an immutable generation as a materialised read model. Products read the index through a public API. Each hop can be behind the one before it, so every answer carries the generation identifier and indexed height it was computed at. No third-party blockchain data provider sits in any production path.

The services

Service	Authoritative for	Read
Atomicals ElectrumX	Protocol interpretation of blocks	ElectrumX reference
ARC-20 index and feed	Verified tickers, holders, confirmed activity	ARC-20 API
NFT and Realm index	Plain NFTs, Realms, Subrealms	NFT and Realm API
Marketplace v1 authority	Listings, reservations, purchases, settlements	Marketplace v1
Ordex contract	Marketplace contract, SDK, conformance	Ordex

Data sovereignty

All Bitcoin and Atomicals data comes from Universe-operated nodes, indexes, and databases. No third-party blockchain data provider sits in any production path.

What each index is not

• Not a validator. Both indexes project what an Atomicals provider reports.
• Not complete. Each declares its projection, and each excludes asset kinds on purpose.
• Not final. Every answer is scoped to a generation and a chain position.

Projections

The NFT and Realm read model declares its projection explicitly:

• Included: plain NFT, Realm, Subrealm.
• Excluded: FT, DFT, Container, DMItem.

Fungible tokens are served by the ARC-20 side. Containers and DMINT items are not projected by either.

Read next

Topic	Page
Where data comes from and what it costs to trust	Data flow
How to decide which answer to believe	Source of truth
Generations, checkpoints, and rollback	Consistency and reorgs
Identifiers, networks, and protocol IDs	Identifiers and networks
Authentication across the services	Authentication
Error envelopes	Errors
Cursors and paging	Pagination and cursors
Safe retries and tracing	Idempotency and request IDs
Readiness against configured	Readiness and freshness
Rate limits where they exist	Rate limits
Versioning and deprecation	Versioning and deprecation
Moving between versions	Migration