BackendGen MCP server

BackendGen

BackendGen is a deterministic backend compiler for AI coding agents. Give an agent a compact, versioned YAML or JSON specification and it can generate a structured, tested backend instead of inventing database models, permissions, API routes, and migrations from scratch.

It currently generates NestJS 11 + Prisma 6 + PostgreSQL repositories, including a typed TypeScript client and a small frontend-contract.json for the frontend agent to consume. Generated projects have no BackendGen runtime dependency.

Alpha status: BackendGen is ready for design-partner trials and local

projects. Review generated applications before production use; it has not yet

completed independent security review or three design-partner trials.

npm CLI · npm MCP server · Report an issue · Design-partner program

What it is for

BackendGen is useful when an AI agent needs a real backend behind a frontend:

custom code;

• model entities, relations, filters, sorting, and pagination;
• add authentication, roles, row ownership, organizations, and tenant isolation;
• generate reservations, notifications, webhooks, durable jobs, and uploads;
• preserve a clean boundary between compiler-owned code and application-owned

and explicit review gates for destructive changes.

• safely regenerate after a specification changes, with incremental migrations

BackendGen is not a hosted backend service, deployment platform, or frontend builder. It runs locally and produces code that a developer or coding agent can review, customize, test, deploy, and connect to a frontend.

Requirements

• Node.js 22 or newer
• npm 10 or newer
• PostgreSQL only when you want to run a generated project's integration tests

Try it in five minutes

You do not need an npm account or this repository to try BackendGen.

mkdir backendgen-try
cd backendgen-try

npx -y @2hemi/backendgen init backend.yaml --name team-api
npx -y @2hemi/backendgen validate backend.yaml
npx -y @2hemi/backendgen generate backend.yaml --output ./team-api

cd team-api
npm install
npm test

The generated project runs prisma generate during installation, so this first-run path does not require a separate Prisma command. From the parent directory, use npx -y @2hemi/backendgen test-generated --output ./team-api --install when an agent should perform installation, validation, build, and unit tests through one bounded compiler command.

init creates a valid starter specification. Edit backend.yaml, then run validate and generate again. Before regenerating an existing project, use diff to preview what would change:

npx -y @2hemi/backendgen diff backend.yaml --output ./team-api

Test a complete SaaS example

The repository includes working specifications from basic CRUD to a full-featured backend. This multi-tenant task example is a good first test:

git clone https://github.com/SiTouhemi/Backendgen.git
cd Backendgen

npx -y @2hemi/backendgen validate examples/saas-tasks/backend.yaml
npx -y @2hemi/backendgen generate examples/saas-tasks/backend.yaml --output ./generated/saas-tasks

cd generated/saas-tasks
npm install
npm test

Browse every example and what it demonstrates in examples/README.md:

Shortened. The full README is on GitHub.