Data sources

A data source is a named database client that resources read from and write to. Data sources live in their own directory, passed as the second argument to CroutonApiModule.forResourceDir.

Folder convention

data-sources/
└── maindb/
    ├── data-source.json
    └── index.ts

data-source.json

Every datasource is self-describing: a single data-source.json holds both what the runtime needs to connect and what the CLI / codegen needs to introspect and generate.

{
  "type": "postgres",
  "name": "maindb",
  "default": true,
  "prismaSchema": "prisma/maindb/schema.prisma",
  "urlEnv": "DATABASE_URL",
  "generatedTypesImport": "@my-app/generated/maindb",
  "zodOutput": "generated/maindb/src",
  "prismaConfig": "prisma/maindb/prisma.config.ts"
}

Runtime fields

These are read by crouton-api at startup:

Field	Description
name	Name used by resources to select this data source (the database field in resource.json). Defaults to the folder name.
type	Client type — currently Prisma.
default	Used by resources that don't specify a database. Exactly one datasource may be default.

Codegen fields

These are read only by the crouton CLI / codegen engine; the runtime ignores them. They make multiple datasources possible by giving each its own schema and generated outputs.

Field	Description
prismaSchema	Path to this datasource's Prisma schema, relative to the project root.
urlEnv	Env var holding the connection URL used when the CLI runs prisma db pull / generate.
generatedTypesImport	Import path for this datasource's generated Zod types. New schema.ts files re-export from here.
zodOutput	This datasource's zod-prisma-types output dir (project-relative).
prismaConfig	Prisma config file for this datasource. Defaults to prisma/<name>/prisma.config.ts.

index.ts

Default-export a configured PrismaClient:

import { PrismaClient } from '@prisma/client';
import { PrismaPg } from '@prisma/adapter-pg';

const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL,
});

const client = new PrismaClient({ adapter });

export default client;

Multiple databases

Add one folder per database and reference them by name. Each datasource owns a separate Prisma schema and generated output so the generated clients and Zod types never collide:

prisma/
├── maindb/
│   ├── schema.prisma       # generator output → generated/maindb
│   └── prisma.config.ts    # binds maindb's urlEnv
└── archivedb/
    ├── schema.prisma       # generator output → generated/archivedb
    └── prisma.config.ts

generated/
├── maindb/                 # zodOutput for maindb
└── archivedb/

data-sources/
├── maindb/                 # default: true
└── archivedb/

// resources/legacy_record/resource.json
{
  "name": "legacy_record",
  "database": "archivedb",
  ...
}

Resources without a database field use the data source marked default: true. A single datasource can keep flat paths (e.g. prisma/schema.prisma, generated/types) — the per-<name> layout above only becomes necessary once a second datasource is added.

The CLI discovers datasources by scanning the data-sources directory (set in crouton.json); they are not listed anywhere else.