Output Descriptors

Output Descriptors provide a standardized way to describe Bitcoin output scripts and spending conditions. BIP 380 defines them. They encode wallet policies in a compact string without revealing private keys. Also called wallet descriptors.

Output descriptors work through a human-readable notation. This notation specifies keys, scripts, and derivation paths. For example, wpkh(02f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9) describes a pay-to-witness-public-key-hash output using a specific public key. Complex setups use multi(2,pubkey1,pubkey2,pubkey3) for 2-of-3 multisig. A checksum at the end validates the string. Ranges like [d34db33f/84h/0h/0h/*] support hierarchical deterministic (HD) key generation.

They matter for security and portability. Users back up wallets by sharing descriptors, not keys. Different software reconstructs addresses and policies from the descriptor. This prevents key exposure in multisig or hardware wallet setups. Descriptors enable policy sharing without trust issues.

Key characteristics include support for various script types: pk for public keys, pkhash and wpkh for hashes, multi and sortedmulti for multisig, tr for taproot, and wrappers like sh (P2SH) or wsh (P2WSH). They handle modifiers for sorted keys, thresholds, and miniscripts.