BIP 386 guide covering deployed tr() descriptors, internal x-only keys, optional script trees, TapTweak construction, parser boundaries, recovery and vectors.
This guide explains BIP 386 tr() output descriptors in plain English. It covers the problem behind the BIP, why it matters and whether the proposal is part of Bitcoin today.
BIP 386 tr() output descriptors: tr(KEY) describes a key-path output with no intended spendable script path. Tr(KEY,TREE) describes the same internal-key route plus one or more script leaves arranged in an explicit binary tree.
A node operator is checking BIP 386 tr() output descriptors. Lift the key to an x-only point, calculate the TapTweak with either the internal key alone or the key plus Merkle root, add the tweak times G, and encode OP_1 followed by the 32-byte output key.
BIP 386 is Deployed and Informational, requires BIP 380 and has been implemented in Bitcoin Core since 22.0. Pin parser behaviour because later descriptor fragments expand what may appear in trees.
tr(KEY) describes a key-path output with no intended spendable script path. Tr(KEY,TREE) describes the same internal-key route plus one or more script leaves arranged in an explicit binary tree.
Lift the key to an x-only point, calculate the TapTweak with either the internal key alone or the key plus Merkle root, add the tweak times G, and encode OP_1 followed by the 32-byte output key.
A tree is either an allowed script expression or a brace-delimited pair of trees. Shape affects branch hashes and control-block paths, so semantically similar leaves in a different tree can produce a different output.
Keys beneath tr() must produce x-only public keys. Uncompressed public keys are forbidden; compressed keys and extended-key descendants are converted to their x-only form.
The descriptor language was new even when output scripts were recognised. Preserve the full checksummed descriptor, origins, ranges, indexes and intended tree rather than backing up only an address or internal key.
Developers test the proposal with made-up data on an isolated test network. They check normal cases and deliberately invalid cases. Different implementations should reach the same result before anyone relies on the proposal.
BIP 386 tr() output descriptors: tr(KEY) describes a key-path output with no intended spendable script path.
BIP 386 is Deployed and Informational, requires BIP 380 and has been implemented in Bitcoin Core since 22.0.
tr(KEY) describes a key-path output with no intended spendable script path.
Lift the key to an x-only point, calculate the TapTweak with either the internal key alone or the key plus Merkle root, add the tweak times G, and encode OP_1 followed by the 32-byte output key.
BIP 386 gives wallets a reproducible language for Taproot outputs. Safe use depends on exact key conversion, tree structure, tweak calculation and full descriptor recovery, not merely producing a Bech32m address.
Check the current specification status and the documentation for the exact implementation you operate before moving production funds or changing a mining node.
BIP 450 guide to Draft Formosa themed mnemonic stories, entropy and checksum mapping, theme JSON, BIP39 conversion, passphrases and recovery safety.
BIP 393 guide to Draft descriptor annotations for birth height, gap limit and Silent Payment max label, checksum rules, parsing and recovery safety.
BIP 392 guide to Draft sp() descriptors, spscan and spspend encodings, watch-only and full-wallet forms, key origins, recovery and validation.
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