Lovable DIY

A self-hosted app builder inspired by Lovable, Bolt.new, and v0. An agent writes the app in an isolated Tensorlake sandbox while you follow the live preview. You can edit through chat, restore earlier versions, share projects, and publish static builds.

Built by @shricodev.

Local setup

pnpm install
cp .env.example .env        # then fill in TENSORLAKE_API_KEY + an LLM key, and AUTH_SECRET (openssl rand -base64 32)
pnpm infra:up               # postgres, minio
pnpm s3:setup               # create + lock down the bucket
pnpm spike spikes/01-create-run.ts   # sanity-check Tensorlake access
pnpm db:migrate             # create tables
pnpm sandbox:build-base     # build the warm base snapshot (~45 s, once per template change)
pnpm dev                    # web :3000, preview gateway :4000, worker
pnpm sandbox:bench -- --keep   # cold vs snapshot vs fork timings; leaves one preview running
pnpm agent:run --fixture habit-tracker   # one full agent turn (or: pnpm agent:run "a pomodoro timer")

Open http://localhost:3000 and sign in with the dev login (any username). Previews are served from http://<project-id>.preview.localhost:4000 and published sites from http://<slug>.app.localhost:4000, each on its own origin (*.localhost resolves to 127.0.0.1 in modern browsers).

MinIO console: http://localhost:9001 (lovable-diy / lovable-diy-dev-secret).

Tests and evals

pnpm test               # unit tests (no credentials needed; what CI runs)
pnpm test:integration   # real sandbox + Postgres: network egress, secrets, path escapes, crash recovery, quotas
pnpm eval               # every fixture × Claude Sonnet 5 and GPT-5.5; JSON + HTML report to .lovable-diy/evals and S3

Repository layout

Path	What
`apps/web`	Next.js UI, auth, APIs, SSE, published-site serving
`apps/worker`	pg-boss jobs: agent turns (with heal loop), remix/duplicate, reaper; eval CLI
`apps/gateway`	preview reverse proxy (HTTP + WebSocket), wake-on-request
`packages/sandbox`	the only code that talks to Tensorlake
`packages/llm`	Anthropic / OpenAI / Ollama behind one interface
`packages/db`	Drizzle schema, migrations, queries
`packages/storage`	the only code that talks to S3
`packages/shared`	env validation, logging, errors, retry
`spikes/`	Phase 0 capability proofs against real Tensorlake
`infra/`	docker compose, S3 setup + IAM policy, sandbox image

Storage layout (one private bucket)

Prefix	Contents
`exports/<project>/<id>.zip`	source exports (expire after 7 days)
`screenshots/<project>/<version>.png`	version thumbnails
`published/<slug>/<version>/…`	published static builds
`evals/<run-id>/…`	eval reports
`uploads/<user>/<id>`	prompt image attachments

Real S3 setup

Create an IAM user (or role) for the app and attach infra/s3/iam-policy.json with LOVABLE_DIY_BUCKET_NAME replaced. It grants object read/write/delete and list on that one bucket only.
For the one-time bootstrap, temporarily also attach infra/s3/iam-policy-setup.json (create bucket, public-access block, lifecycle, CORS), run pnpm s3:setup, then detach it.
In .env: remove S3_ENDPOINT and S3_FORCE_PATH_STYLE, set S3_BUCKET, S3_REGION, and the key pair.

The bucket stays private (all four public-access blocks on). Browsers only ever get short-lived presigned URLs.

GitHub OAuth (optional locally)

Go to GitHub → Settings → Developer settings → OAuth Apps → New OAuth App.
Set the homepage URL to http://localhost:3000 and the authorization callback URL to http://localhost:3000/api/auth/callback/github.
Put the client ID and secret in .env as AUTH_GITHUB_ID / AUTH_GITHUB_SECRET, then restart pnpm dev. The login page shows "Continue with GitHub" automatically.