Tandem

An object two people create and hold together. The active object is an exact 2-of-2 output, so both current keys are required for any cooperative action: adding a chapter, rotating one or both keys, or closing. If collaboration stops, a recovery transaction prepared in advance becomes usable once its relative lock matures.

Chain

Bitcoin

Carrier

An exact 20,000 satoshi native SegWit 2-of-2 P2WSH output

Operations

open, chapter, rotate, close, recover

Where it came from

An original Bitcoin Universe protocol, published 2025.

Where the specification lives

The specification and reference documentation for Tandem live in bitcoinuniverseio/tandem and are published at https://bitcoinuniverseio.github.io/tandem/. That site is the authority. This page exists so you can find it and compare it with the rest of the estate.

Bitcoin Universe indexes or implements it in bitcoinuniverseio/index-tandem and bitcoinuniverseio/tandem-verifier-rs.

Support in Bitcoin Universe products

Tandem has no marketplace entry in the Core protocol registry, so no Bitcoin Universe product implements a trade path for it. Where a Universe indexer exists, the data is available through that indexer rather than through a product surface.

Provenance

Capability facts on this page were generated from backend/packages/ecosystem-contracts/lib/protocols.js in bitcoinuniverseio/core at 15dd03b5986a. Implemented behaviour is not the same as production availability: see how to read our status.