Miniscript

Miniscript is a structured language for writing Bitcoin scripts. Instead of hand-rolling raw opcodes, an author writes a Miniscript expression such as and_v(v:pk(A), or_d(pk(B), older(1000))). The expression compiles to a valid Bitcoin script, and any Miniscript-aware wallet can analyze that expression to produce the right witness for each spending path without custom logic per policy.

The structure also guarantees properties that are hard to verify on raw script: that every advertised spending path is actually spendable, that the maximum witness size can be computed up front, and that no path is malleable. A higher-level Policy language lets a user describe what they want in even simpler terms and have the compiler pick an efficient Miniscript.

Miniscript is implemented in rust-miniscript and used by descriptor wallets including Bitcoin Core, BDK, Liana, and most modern multisig coordinators.

References

• bitcoin.sipa.be/miniscript
• rust-bitcoin/rust-miniscript
• Bitcoin Core descriptors