Package map

You install the core, then only the generators your project uses. Installing the CLI pulls no code generator.

Core (npm)

Package	What it does
@seampact/cli	the seampact command: compile, check, lint, diff, generate, bundle (packs a contract to publish), explain (prints one operation whole with where each part comes from) and init (starts a contract project)
@seampact/compiler	reads the YAML, reports errors with file, line and column, and produces the IR
@seampact/spec	the JSON Schemas of the YAML files, one per file and fragment kind for your editor, and of the IR, with their TypeScript types
@seampact/openapi	writes the OpenAPI 3.1 documents your configs ask for (one per api or declared document, or one merged across a monorepo’s apps), with what OpenAPI cannot say as published x-seampact-* extensions
@seampact/lint	lint rules over the IR, and the API to write your own
@seampact/diff	classifies changes between two versions as additive or breaking, per direction
@seampact/codegen-core	the API code generators are written against

Code generators for TypeScript (npm)

You want	Install
types only	@seampact/codegen-ts
validators	@seampact/codegen-zod, @seampact/codegen-yup or @seampact/codegen-class-validator
a typed fetch client	@seampact/codegen-fetch
a server boundary	@seampact/codegen-nestjs, @seampact/codegen-fastify, @seampact/codegen-express or @seampact/codegen-adonis, plus @seampact/server-runtime as a production dependency, at the same version as the generators, and @seampact/hooks unless the target vendors its types
React hooks (TanStack Query, SWR, RTK Query or no library)	@seampact/codegen-react
an Angular or Vue client	@seampact/codegen-angular or @seampact/codegen-vue
a Web-standard server boundary (Hono 4)	@seampact/codegen-hono
mock handlers for tests and local work	@seampact/codegen-msw

A server generator does not install a validator generator. You choose one and link the two in your app’s seampact.config.yaml, where you also turn each generated artefact on or off. The CLI checks the combination against a published compatibility matrix and, when it does not work, names the ones that do.

codegen-class-validator works on codegen-nestjs only, and the app must load reflect-metadata once at startup (import "reflect-metadata" in its entry file) for the decorators to work.

Each app of a repository (frontend, backend, service) has its own seampact.config.yaml; a monorepo can add a root one that lists the apps and shares contract sources. An app that only needs the OpenAPI document installs no generator at all, and an app that wants no seampact document says so.

Java and PHP

These run with no Node.js installed. The standalone compiler binary (built for linux x64 and arm64, macOS x64 and arm64, Windows x64; see the compiler binary) runs compile, lint (core rules), diff, explain and bundle. generate and check run through the npm CLI or the Gradle, Maven or Composer plugin. The Gradle and Maven plugins read seampact.config.yaml or the same keys in their own DSL.

Framework	Install
Spring Boot 4	the Gradle plugin io.github.jubasse.seampact or the Maven plugin io.github.jubasse:seampact-maven-plugin, io.github.jubasse:seampact-spring-runtime (the Gradle plugin adds it, Maven declares it; the app provides Spring Boot itself), and io.github.jubasse:seampact-hooks unless the target vendors its types
Laravel	seampact/laravel as a dependency (not --dev), and seampact/hooks unless the target vendors its types
Symfony	seampact/symfony as a dependency (not --dev), and seampact/hooks unless the target vendors its types

Python

These are Python packages, installed from PyPI. See FastAPI, Django REST Framework and Django Ninja.

Framework	Install
FastAPI	seampact-fastapi (add the generate extra in your dev dependencies)
Django REST Framework	seampact-drf (add the generate extra in your dev dependencies)
Django Ninja	seampact-ninja (add the generate extra in your dev dependencies)
signed webhooks	seampact-signed-webhooks

Optional packages

Package	Use it when
@seampact/pack-crud-rights	you want a <resource>.<op> right on every route the ops shorthand generates, batch included, without declaring each one
@seampact/pack-laravel	your api serves Laravel API Resources and paginators
@seampact/pack-spring	your api serves Spring Data Page bodies
@seampact/pack-jsonapi	your api speaks JSON:API
@seampact/pack-hal	your api serves HAL
@seampact/signed-webhooks, and its Java and PHP equivalents	you receive Stripe-style or GitHub-style signed webhooks and want the signature checked for you; other senders (Standard Webhooks, Slack) are verified by your own hook with their own library
@seampact/http-suite	you write your own server target and want to prove it against the shared HTTP suite

Next: Install, or the glossary.