Miniscript - Revision history

NotATether: Restore content and fix Policy and Output contexts sections

2026-09-13T07:34:07Z

Restore content and fix Policy and Output contexts sections

← Older revision		Revision as of 07:34, 13 September 2026
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	A policy such as “two of these three keys, or one key after a relative delay” is written in a functional notation and compiled to Miniscript, then to Script. Fragments include <code>pk_k</code>, <code>pk_h</code>, <code>older</code>, <code>after</code>, <code>sha256</code>, <code>hash256</code>, <code>and_v</code>, <code>or_b</code>, <code>thresh</code>, and others. Each fragment has a type and properties that describe malleability, whether it can be satisfied without a signature, and how large the script and witness will be. Type checking rejects compositions that leave the stack wrong or that are malleable under standard rules. Given available secrets, a satisfier can construct a witness. These properties let a wallet predict fees, detect incomplete [[PSBT]]s, and refuse a satisfaction another party could later mutate.		A policy such as “two of these three keys, or one key after a relative delay” is written in a functional notation and compiled to Miniscript, then to Script. Fragments include <code>pk_k</code>, <code>pk_h</code>, <code>older</code>, <code>after</code>, <code>sha256</code>, <code>hash256</code>, <code>and_v</code>, <code>or_b</code>, <code>thresh</code>, and others. Each fragment has a type and properties that describe malleability, whether it can be satisfied without a signature, and how large the script and witness will be. Type checking rejects compositions that leave the stack wrong or that are malleable under standard rules. Given available secrets, a satisfier can construct a witness. These properties let a wallet predict fees, detect incomplete [[PSBT]]s, and refuse a satisfaction another party could later mutate.

	~~Wallets that export~~ descriptors ~~containing~~ Miniscript ~~should keep~~ the ~~policy string~~ and ~~the compiled Miniscript in sync~~. A ~~hand-edited script that no longer matches~~ the ~~analyzed type system~~ can ~~still~~ be ~~consensus-valid while defeating fee prediction and PSBT satisfaction helpers~~.		Miniscript does not cover every Script opcode. It targets standard P2WSH and Tapscript spending under [[Segregated Witness]] and [[Taproot]]. Some valid scripts have no Miniscript form. Compilers try to choose a small, non-malleable representation. In descriptors, Miniscript appears as the argument to <code>wsh()</code> or as leaves of <code>tr()</code>, with key expressions following BIP380 (including origin fingerprints and BIP32 paths). A descriptor checksum covers the whole string so a policy can be backed up as text.

	== Output contexts ==		== Output contexts ==

	Miniscript ~~does not cover every Script opcode. It targets standard P2WSH~~ and ~~Tapscript~~ spending ~~under [[Segregated Witness]]~~ and ~~[[Taproot]]. Some valid scripts have no~~ Miniscript ~~form~~. ~~Compilers try to choose a small, non~~-~~malleable representation. In descriptors, Miniscript appears as~~ the ~~argument~~ to ~~<code>wsh()</code> or as leaves of <code>tr()</code>~~, ~~with key expressions following BIP380 (including origin fingerprints~~ and ~~BIP32 paths). A descriptor checksum covers the whole string so~~ a ~~policy can be backed up as text~~.		Bitcoin Core can import Miniscript inside descriptors for watch-only and spending wallets that understand the language. Hardware and software signers that speak PSBT can satisfy Miniscript leaves when the policy fragments match their key paths. Libraries such as rust-miniscript and the reference C++ implementation are used to compile policies, estimate witness weight, and analyze whether a script is safe under standard relay rules.

			Taproot Miniscript differs slightly from P2WSH Miniscript because Tapscript opcodes and resource limits differ. A policy compiled for <code>wsh()</code> is not automatically valid as a <code>tr()</code> leaf. Designers therefore keep separate compilers or ciphersuites per output context. Miniscript does not replace Script consensus rules. Invalid or nonstandard scripts remain invalid even if a broken compiler emits them. Wallets that export descriptors containing Miniscript should keep the policy string and the compiled Miniscript in sync. A hand-edited script that no longer matches the analyzed type system can still be consensus-valid while defeating fee prediction and PSBT satisfaction helpers.

	== See also ==		== See also ==

NotATether: Add Policy and fragments and Output contexts sections

2026-09-13T07:33:20Z

Add Policy and fragments and Output contexts sections

← Older revision		Revision as of 07:33, 13 September 2026
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	Arbitrary Script is hard to analyze: it is not obvious whether a script is spendable, whether two scripts encode the same policy, what witness is required, or whether a proposed satisfaction is minimal. Wallets that implement multisignature or timelocked recovery therefore tend to hard-code a few templates. Pieter Wuille, Andrew Poelstra, and Sanket Kanjalkar designed Miniscript as a composition-friendly representation of the Script subset used for spending policies. A higher-level ''policy'' language describes thresholds, keys, hashes, and timelocks; Miniscript itself is closer to Script and carries type information for correct compilation.		Arbitrary Script is hard to analyze: it is not obvious whether a script is spendable, whether two scripts encode the same policy, what witness is required, or whether a proposed satisfaction is minimal. Wallets that implement multisignature or timelocked recovery therefore tend to hard-code a few templates. Pieter Wuille, Andrew Poelstra, and Sanket Kanjalkar designed Miniscript as a composition-friendly representation of the Script subset used for spending policies. A higher-level ''policy'' language describes thresholds, keys, hashes, and timelocks; Miniscript itself is closer to Script and carries type information for correct compilation.

			== Policy and fragments ==

	A policy such as “two of these three keys, or one key after a relative delay” is written in a functional notation and compiled to Miniscript, then to Script. Fragments include <code>pk_k</code>, <code>pk_h</code>, <code>older</code>, <code>after</code>, <code>sha256</code>, <code>hash256</code>, <code>and_v</code>, <code>or_b</code>, <code>thresh</code>, and others. Each fragment has a type and properties that describe malleability, whether it can be satisfied without a signature, and how large the script and witness will be. Type checking rejects compositions that leave the stack wrong or that are malleable under standard rules. Given available secrets, a satisfier can construct a witness. These properties let a wallet predict fees, detect incomplete [[PSBT]]s, and refuse a satisfaction another party could later mutate.		A policy such as “two of these three keys, or one key after a relative delay” is written in a functional notation and compiled to Miniscript, then to Script. Fragments include <code>pk_k</code>, <code>pk_h</code>, <code>older</code>, <code>after</code>, <code>sha256</code>, <code>hash256</code>, <code>and_v</code>, <code>or_b</code>, <code>thresh</code>, and others. Each fragment has a type and properties that describe malleability, whether it can be satisfied without a signature, and how large the script and witness will be. Type checking rejects compositions that leave the stack wrong or that are malleable under standard rules. Given available secrets, a satisfier can construct a witness. These properties let a wallet predict fees, detect incomplete [[PSBT]]s, and refuse a satisfaction another party could later mutate.

			Wallets that export descriptors containing Miniscript should keep the policy string and the compiled Miniscript in sync. A hand-edited script that no longer matches the analyzed type system can still be consensus-valid while defeating fee prediction and PSBT satisfaction helpers.

			== Output contexts ==

	Miniscript does not cover every Script opcode. It targets standard P2WSH and Tapscript spending under [[Segregated Witness]] and [[Taproot]]. Some valid scripts have no Miniscript form. Compilers try to choose a small, non-malleable representation. In descriptors, Miniscript appears as the argument to <code>wsh()</code> or as leaves of <code>tr()</code>, with key expressions following BIP380 (including origin fingerprints and BIP32 paths). A descriptor checksum covers the whole string so a policy can be backed up as text.		Miniscript does not cover every Script opcode. It targets standard P2WSH and Tapscript spending under [[Segregated Witness]] and [[Taproot]]. Some valid scripts have no Miniscript form. Compilers try to choose a small, non-malleable representation. In descriptors, Miniscript appears as the argument to <code>wsh()</code> or as leaves of <code>tr()</code>, with key expressions following BIP380 (including origin fingerprints and BIP32 paths). A descriptor checksum covers the whole string so a policy can be backed up as text.

	Bitcoin Core can import Miniscript inside descriptors for watch-only and spending wallets that understand the language. Hardware and software signers that speak PSBT can satisfy Miniscript leaves when the policy fragments match their key paths. Libraries such as rust-miniscript and the reference C++ implementation are used to compile policies, estimate witness weight, and analyze whether a script is safe under standard relay rules.

	Taproot Miniscript differs slightly from P2WSH Miniscript because Tapscript opcodes and resource limits differ. A policy compiled for <code>wsh()</code> is not automatically valid as a <code>tr()</code> leaf. Designers therefore keep separate compilers or ciphersuites per output context. Miniscript does not replace Script consensus rules. Invalid or nonstandard scripts remain invalid even if a broken compiler emits them.

	== See also ==		== See also ==

NotATether: Remove redlink See also target

2026-09-13T07:19:37Z

Remove redlink See also target

← Older revision		Revision as of 07:19, 13 September 2026
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	* [[Segregated Witness]]		* [[Segregated Witness]]
	* [[PSBT]]		* [[PSBT]]
	* [[Output descriptors]]

	== External links ==		== External links ==

NotATether: Expand See also links

2026-09-13T07:19:21Z

Expand See also links

← Older revision		Revision as of 07:19, 13 September 2026
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	* [[Segregated Witness]]		* [[Segregated Witness]]
	* [[PSBT]]		* [[PSBT]]
			* [[Output descriptors]]

	== External links ==		== External links ==

NotATether: Add Taproot versus P2WSH context

2026-09-13T07:19:19Z

Add Taproot versus P2WSH context

← Older revision		Revision as of 07:19, 13 September 2026
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	Bitcoin Core can import Miniscript inside descriptors for watch-only and spending wallets that understand the language. Hardware and software signers that speak PSBT can satisfy Miniscript leaves when the policy fragments match their key paths. Libraries such as rust-miniscript and the reference C++ implementation are used to compile policies, estimate witness weight, and analyze whether a script is safe under standard relay rules.		Bitcoin Core can import Miniscript inside descriptors for watch-only and spending wallets that understand the language. Hardware and software signers that speak PSBT can satisfy Miniscript leaves when the policy fragments match their key paths. Libraries such as rust-miniscript and the reference C++ implementation are used to compile policies, estimate witness weight, and analyze whether a script is safe under standard relay rules.

			Taproot Miniscript differs slightly from P2WSH Miniscript because Tapscript opcodes and resource limits differ. A policy compiled for <code>wsh()</code> is not automatically valid as a <code>tr()</code> leaf. Designers therefore keep separate compilers or ciphersuites per output context. Miniscript does not replace Script consensus rules. Invalid or nonstandard scripts remain invalid even if a broken compiler emits them.

	== See also ==		== See also ==

NotATether: Add wallet and library adoption

2026-09-13T07:19:17Z

Add wallet and library adoption

← Older revision		Revision as of 07:19, 13 September 2026
Line 6:		Line 6:

	Miniscript does not cover every Script opcode. It targets standard P2WSH and Tapscript spending under [[Segregated Witness]] and [[Taproot]]. Some valid scripts have no Miniscript form. Compilers try to choose a small, non-malleable representation. In descriptors, Miniscript appears as the argument to <code>wsh()</code> or as leaves of <code>tr()</code>, with key expressions following BIP380 (including origin fingerprints and BIP32 paths). A descriptor checksum covers the whole string so a policy can be backed up as text.		Miniscript does not cover every Script opcode. It targets standard P2WSH and Tapscript spending under [[Segregated Witness]] and [[Taproot]]. Some valid scripts have no Miniscript form. Compilers try to choose a small, non-malleable representation. In descriptors, Miniscript appears as the argument to <code>wsh()</code> or as leaves of <code>tr()</code>, with key expressions following BIP380 (including origin fingerprints and BIP32 paths). A descriptor checksum covers the whole string so a policy can be backed up as text.

			Bitcoin Core can import Miniscript inside descriptors for watch-only and spending wallets that understand the language. Hardware and software signers that speak PSBT can satisfy Miniscript leaves when the policy fragments match their key paths. Libraries such as rust-miniscript and the reference C++ implementation are used to compile policies, estimate witness weight, and analyze whether a script is safe under standard relay rules.

	== See also ==		== See also ==

NotATether: Create Miniscript stub (structured Script / descriptors)

2026-09-12T04:50:31Z

Create Miniscript stub (structured Script / descriptors)

New page

'''Miniscript''' is a language for writing a structured subset of Bitcoin [[Script]]. A Miniscript expression compiles to Script, can be analyzed for correctness, size, and satisfaction, and can be composed from smaller expressions. It is used with output descriptors, typically inside <code>wsh()</code> or <code>tr()</code>, so wallets can import a spending policy rather than a raw script hex blob.

Arbitrary Script is hard to analyze: it is not obvious whether a script is spendable, whether two scripts encode the same policy, what witness is required, or whether a proposed satisfaction is minimal. Wallets that implement multisignature or timelocked recovery therefore tend to hard-code a few templates. Pieter Wuille, Andrew Poelstra, and Sanket Kanjalkar designed Miniscript as a composition-friendly representation of the Script subset used for spending policies. A higher-level ''policy'' language describes thresholds, keys, hashes, and timelocks; Miniscript itself is closer to Script and carries type information for correct compilation.

A policy such as “two of these three keys, or one key after a relative delay” is written in a functional notation and compiled to Miniscript, then to Script. Fragments include <code>pk_k</code>, <code>pk_h</code>, <code>older</code>, <code>after</code>, <code>sha256</code>, <code>hash256</code>, <code>and_v</code>, <code>or_b</code>, <code>thresh</code>, and others. Each fragment has a type and properties that describe malleability, whether it can be satisfied without a signature, and how large the script and witness will be. Type checking rejects compositions that leave the stack wrong or that are malleable under standard rules. Given available secrets, a satisfier can construct a witness. These properties let a wallet predict fees, detect incomplete [[PSBT]]s, and refuse a satisfaction another party could later mutate.

Miniscript does not cover every Script opcode. It targets standard P2WSH and Tapscript spending under [[Segregated Witness]] and [[Taproot]]. Some valid scripts have no Miniscript form. Compilers try to choose a small, non-malleable representation. In descriptors, Miniscript appears as the argument to <code>wsh()</code> or as leaves of <code>tr()</code>, with key expressions following BIP380 (including origin fingerprints and BIP32 paths). A descriptor checksum covers the whole string so a policy can be backed up as text.

== See also ==
* [[Script]]
* [[Taproot]]
* [[Segregated Witness]]
* [[PSBT]]

== External links ==
* [https://bitcoin.sipa.be/miniscript/ Miniscript reference]
* [https://bitcoinops.org/en/topics/miniscript/ Bitcoin Optech: Miniscript]
* [https://github.com/bitcoin/bips/blob/master/bip-0380.mediawiki BIP380: Output Script Descriptors General Operation]
* [https://github.com/rust-bitcoin/rust-miniscript rust-miniscript]

[[Category:Technical]]