Plutus Core Team Update

High level summary

Plutus Core

• We made a number of performance optimizations and refactoring for the Plutus evaluator and deserializer, including #7272, #7281, #7286, #7287, and #7296.

• We added support for built-in units and pairs. This functionality will be enabled at the upcoming intra-era hard fork.

• We continued developing the UPLC-CAPE benchmark, aimed to compare the performances of different surface languages targeting UPLC. A presentation on this was given in the Plutus working group meeting on September 2nd, 2025.

Plinth

• We added a Plinth library function, caseInteger that compiles to casing on integers in UPLC, a feature that will be enabled at the upcoming intra-era hard fork.

• We made the compilation fail early with a better error message when an unsupported Haskell language extension is used.

• We added more source code location information to Plinth compiler's compilaton trace (which can be obtained using the dump-compilation-trace flag), and the error message when the compilation fails.

Low level summary

Key Pull Requests Merged

• Fix natural number flat encoding on the spec
• Add 'CekResult' and improve 'dischargeCekValue'
• Make FrameAwaitFunValue handle multiple arguments at once
• Throw compilation error when unsupported extension is enabled
• Add Plinth builtin for integer casing
• [OPTIMIZATION] Use specialized ArgStack
• [OPTIMIZATION] Use spine directly for constant casing
• Flat: encode UPLC arrays as lists
• Add SrcSpans of Vars in the compilation trace
• [Builtins] Add constant casing for builtin unit and pair
• [UPLC-CAPE] Define Two-Party Escrow benchmark scenario

Issues and Pull Requests In Progress

• Add BuiltinValue type to plutus-core
• Add MSM builtin