Build a Bolt-style app

What you’re building: a full-stack app builder. Prompts become an app with a real server, a database, and a live URL.

Primitives you’ll use: Organization, Sandboxes, Agents, Postgres, Deployments, Custom domains

What you’re building

Bolt-style products generate full-stack apps, not just frontends: a server, an API, an environment file, and a database. That means the thing you publish has to keep running, not just serve static files.

On MIOSA, the workspace is a sandbox with Node and pnpm. The agent scaffolds the app, writes the server, starts it, and you publish it as a dynamic deployment (give it a run command and a port). Attach a managed Postgres so the app has a real DATABASE_URL in the sandbox and in production, and the same code runs in both places.

Keep the workspace alive between turns so follow-up prompts edit the same app.

What you need on MIOSA

Architecture

Step 1: Create an account and an API key

Install the CLI, sign in, and mint a key for your product. The secret is printed once; store it as an environment variable, never in code.

npm i -g @miosa/cli
miosa login
miosa whoami
miosa api-key create bolt-app-key --preset agent     # prints the secret once
export MIOSA_API_KEY="msk_u_..."

Both SDKs read MIOSA_API_KEY from the environment, so a server or a worker needs nothing else. See API keys for scopes and how to create keys in the console.

Step 2: Create the resources

Set DATABASE_URL in the sandbox environment (or on the project) so the generated code reads it exactly as it will in production.

Step 3: Wire the agent loop

Because the app has a server, publish it as a dynamic deployment (next step) with --run-command "npm start" --port 3000.

Step 4: Preview

A Preview is a throwaway public URL for a port inside the machine. Start the app as a background process so it survives the CLI disconnecting, then expose its port.

Open the exact Preview URL MIOSA returns.

Step 5: Deploy

Publish the machine to an immutable Deployment. Give it the source machine, the path the app lives at inside it, and the command that serves it.

Publishing the same deployment name again creates a new immutable version and keeps the same URL. Roll back with miosa deploy rollback bolt-app --to <version-id>, and inspect a live app with miosa deploy logs bolt-app -n 100. See Publishing and Rollback.

Step 6: Custom domain

Attach a domain your customer owns to the deployment. The platform URL keeps working while DNS propagates.

miosa deploy domain-add bolt-app app.example.com
miosa deploy domains bolt-app          # shows the DNS record and verification target
miosa deploy domain-verify bolt-app <domain-id>

Copy the exact DNS record MIOSA shows into the customer’s DNS provider; for a subdomain it is normally a CNAME. Once verified and TLS is active, MIOSA routes the domain to the deployment’s active version. In code, read the URL from the publish response instead of building it: the SDK method is miosa.deployments.domains.add(deploymentId, { domain }) (TypeScript) or miosa.deployments.domains(deployment_id).add(domain=...) (Python). See Domains.

Costs and limits

Everything bills while it runs: machines (sandboxes and computers) by the second, managed databases while running, and deployments when they serve. Pausing a machine stops compute billing but keeps disk. Set an --idle-timeout or a --ttl so a forgotten machine cannot run forever, and cap spend with rate limits and per-workspace quotas.

• Pricing - plans, the published rate card, and the free Developer grant.
• Sizing and limits - machine sizes and what each costs to run.
• Timeouts and auto-stop - --ttl, --idle-timeout, and pause/resume.

Next steps