What Is Reflex Build

Reflex Build is an AI app builder for creating full-stack web apps with natural language and Python. It combines an AI agent, a running preview, a code workspace, testing, integrations, and deployment in one browser-based workflow.

The result is a standard Reflex app with source code you can inspect, edit, connect to Git, download, and deploy.

Describe, Build, Test, and Ship

Start with a prompt that describes the app or change you need. Builder can then plan the work, update the source, run the app, and show the result in Preview.

When a task needs more context, the agent can search the web, run Python, or generate an image. See Agent Tools for when and how those tools are used.

A typical workflow is:

1. Describe one clear outcome and include any useful screenshots, files, or constraints.
2. Review the plan when the work spans several pages, systems, or files.
3. Let the agent implement the change and follow its progress.
4. Test the result in Preview and send focused follow-up instructions.
5. Add or run tests for the workflows that matter.
6. Deploy, share, download, or continue developing the app locally.

For a guided example, follow Your First Reflex Build App. For prompting and review guidance, see Reflex Build Best Practices.

Production Python Code You Own

Builder generates a regular Reflex project rather than an opaque hosted artifact. The project contains the Python application code, assets, dependency definitions, and Reflex configuration needed to run it.

Use Code to browse, search, and edit the source. You can also:

• Connect the app to GitHub or connect its project to another Git provider.
• Download the source and continue development with your own tools.
• Install Python packages when the app needs an external library.
• Use checkpoints and Git history to understand or recover earlier changes.

See Code and Review, Connecting to GitHub, and Download App for the relevant workflows.

Testing Is Built In

Ask the agent to create unit or browser tests in plain language. You can run one test or the full suite, inspect failures, and ask the agent to fix the underlying behavior.

Tests help catch regressions as the app changes, but they do not replace checking the primary workflow with realistic data in Preview. See Automated Testing.

Before deployment, the Security Scanner can check the source and dependencies for common security issues.

Connect to Your Systems

Builder can work with databases, authentication providers, APIs, storage services, AI models, and other external systems.

• Use a packaged integration for a supported service.
• Create a custom integration for internal APIs, shared context, or credentials.
• Add MCP servers when the agent needs access to another tool.
• Install an ordinary Python package when no dedicated integration is required.
• Store credentials in integrations or Secrets, not in prompts or source code.

Only enable the services an app needs. See Integrations, Installing External Packages, and Secrets.

Work with Your Team

An organization contains projects, and each project contains apps. This structure keeps apps, integrations, knowledge, repositories, deployments, and access controls together for a team.

Organizations and projects support members, teams, standard and custom roles, deployment approvals, and audit logs. Developers can work in Builder or through a connected repository while using the same app source.

Start with Organizations for the hierarchy, Project Overview for project-level resources, and Roles and Permissions for access control.

Review Every Change

Use Preview after every meaningful step. When feedback applies to a specific part of the interface, use Review mode to draw on the page, add comments, and send the annotations to the agent.

For larger changes, review the plan before implementation. If a result moves in the wrong direction, inspect the changed files or restore an earlier checkpoint instead of asking the agent to rebuild the entire app.

See Planning, Generation Controls and Collaboration, and Restore a Checkpoint.

Deploy Where You Need It

Deploy an app to Reflex Cloud from Builder, deploy from the command line, or follow the supported cloud and self-hosting workflows. After deployment, you can monitor status and logs, manage domains and settings, review deployment history, and roll back when necessary.

See Deploy an App, Manage a Deployed App, and Cloud Providers.