Definition
An output descriptor is a compact, machine-readable string that fully and unambiguously describes how a set of Bitcoin outputs can be spent. Defined in BIP380 and the related BIP381-386, descriptors solve a real interoperability problem: the same xpub can legitimately produce legacy, wrapped-SegWit, or native-SegWit addresses, and a bare xpub does not say which. Wallets that guessed wrong showed users incorrect addresses and balances. Descriptors end that guessing.
What a descriptor contains
A descriptor wraps the key material in an explicit script expression that names the output type, plus a key expression that states the master-key fingerprint and the exact derivation path. For example, wpkh([d34db33f/84'/0'/0']xpub.../0/*) tells any compliant wallet three things with no ambiguity: build native SegWit P2WPKH outputs, the keys come from the master with that fingerprint via path m/84'/0'/0', and addresses run along the external chain. A trailing checksum guards against transcription errors.
Why it matters for sovereignty
Descriptors are now the preferred way to back up, import, and reconstruct a wallet across software, including multisig setups where every cosigner's path and key must be recorded exactly. Backing up the descriptor alongside your seed means a future recovery tool can rebuild your wallet precisely, without trial-and-error over script types or guessing the gap limit.
Descriptors are the modern, unambiguous successor to passing around a raw extended public key (xpub), and they build directly on the BIP32 HD wallet derivation model.
In Simple Terms
An output descriptor is a compact, machine-readable string that fully and unambiguously describes how a set of Bitcoin outputs can be spent. Defined in BIP380…