Getting started

Gramin turns parser grammar source into a common Grammar IR and a deterministic feature report. It is a structural analysis toolkit, not a parser generator.

Analyze a grammar

Requires Node.js 20 or newer:

npx @gramin/cli analyze grammar.y
npx @gramin/cli analyze grammar.y --format md
npx @gramin/cli analyze grammar.y --format llm --budget-chars 8000

Use an explicit frontend when a filename is ambiguous or when automatic detection reports more than one plausible format:

npx @gramin/cli analyze grammar.y --frontend yacc-family
npx @gramin/cli analyze Json.g4 --frontend antlr4

Automatic detection never silently chooses between tied candidates. That makes a result reproducible and prevents a filename or short header from selecting the wrong grammar family.

Inspect the intermediate representation

The IR is a versioned, machine-readable boundary:

gramin ir grammar.y > grammar-ir.json
gramin validate-ir grammar-ir.json
gramin analyze --ir grammar-ir.json --format json

Use the IR when you want to connect an external frontend, cache parsing separately, or build a tool on top of the stable schema.

Choose an output

Every renderer starts from the same validated feature object:

Output	Best for
json	dashboards, scripts, and snapshots
md	pull-request review and human-readable reports
llm	bounded context for an assistant you control
sarif	GitHub Code Scanning and CI annotations

See How it works for the boundary between parsing, analysis, and reporting.