What is a mod

Informative guide. This Book page explains Beskid but does not define the standard. For normative requirements, use the Beskid Standard.

A compiler mod is a type: Mod package in the dependency graph whose compiled AOT artifact exports SDK contract implementations (generators, analyzers, rewriters), not random scripts the CLI evals.

Not these things

Thing	Mod?
Rust proc-macro inside beskid_analysis	Host implementation detail
Language macro items	Language macros, a parallel feature
User contract Disposable	Structural type contract, different namespace
meta { } blocks in old designs	Removed, Collector owns scope

Discovery

Manifest attachTo folklore is dead. During mod.load the host:

1. Resolves transitive Mod dependencies from CompilePlan
2. Loads AOT artifact for target triple + cache key
3. Reads mod.descriptor.json / export table
4. Schedules (contractId, typeId, entrySymbol) tuples

Duplicates → E1829 / E1851–E1870 before collect runs (Compiler Mod SDK: discovery).

Compiler never in Beskid

The reference compiler host is Rust-only. Mods extend compilation; they do not replace beskid_analysis.

Next

Mod SDK