onramp

OnRamp is an early-stage full-stack Python framework for building apps that run on the web, iOS, and Android with a shared React Native frontend.

Installation

pip install onramp

Project architecture

Generated full-stack projects have two source areas:

• app/ is the Python backend, settings, models, and migrations.
• build/ is the editable universal React Native frontend in the current OnRamp phase. Despite the directory name, it is not disposable output.

Native projects under build/ios/ and build/android/ are added lazily. BACKEND=False disables launching Python alongside the frontend but preserves the backend scaffold for later use.

Create an app

Start a new OnRamp app:

onramp new <app_name>

Run this command from the new app's parent directory. The destination may be missing, empty, or an initialized Git repository containing only .git; OnRamp refuses other non-empty destinations. Generation is staged and only published after the backend and frontend both succeed.

The default is web-first: it creates the shared universal frontend without creating iOS or Android projects. Native projects are added automatically when you first run onramp ios or onramp android.

Create the app with both mobile projects immediately:

onramp new <app_name> --mobile

Create every currently supported frontend platform:

onramp new <app_name> --all

Just create an API (backend)

onramp new <app_name> --api

Run the development server

cd <app_name>
onramp run

If you have only created an API (there is no frontend build folder) then onramp run will only start the dev server for the backend.

If you created a fullstack app, then onramp run will start the dev server for the frontend app and will also start the dev server for the backend app if in your settings you have BACKEND = True.

OnRamp manages database startup and shutdown through Starlette's lifespan API. New projects default to ENVIRONMENT="development" and AUTO_GENERATE_SCHEMAS=True, which creates missing tables for local development. Automatic schema creation is always disabled outside the development environment, even if the flag is left enabled. Set ONRAMP_ENVIRONMENT=production (or update app/settings.py) and apply Aerich migrations before starting a deployed backend.

Run a native app from the project directory:

onramp ios
onramp android
onramp mobile

After the first successful native build, OnRamp reopens the installed app without recompiling when its native inputs are unchanged. JavaScript and TypeScript are still served fresh by Metro. Use onramp ios --rebuild, onramp android --rebuild, or onramp mobile --rebuild to force native compilation and installation.

onramp mobile prepares both native apps and launches Android before iOS so the faster emulator is available first. Each platform gets its own project-owned Metro server, and a backend-enabled project starts only one Python server for both apps.

Check a toolchain without changing the generated app:

onramp doctor web
onramp doctor ios
onramp doctor android

--port controls the Python backend. Native commands independently select a free Metro port so they never attach to an unidentified bundler on port 8081. Use --metro-port <port> to request a specific free port. For onramp mobile, that is the Android port and iOS selects the next available port above it. The selected Metro process remains attached to the command; press Ctrl+C to stop it and any backend process OnRamp started for that run. If a coordinated frontend or native preflight fails, OnRamp stops the backend and returns the failure instead of leaving a backend-only watcher running. The backend watcher reloads for Python source changes while ignoring SQLite, bytecode, static-file, and directory activity. OnRamp also owns the backend worker's signal lifecycle, so one Ctrl+C shuts down and reaps both the frontend and backend processes.

onramp mobile completes all interactive iOS and Android checks before either Metro server starts. It then opens both emulator applications, keeps terminal input in the coordinating OnRamp process, and prefixes concurrent Metro output with [iOS] and [Android]. This prevents one platform's development server from hiding or consuming the other platform's installation prompt. Full native builds report elapsed activity while Xcode or Gradle is quiet, so Xcode's final build-settings and installation work no longer looks stuck.

Native doctor checks validate an installed Watchman binary. On macOS, Metro uses its native filesystem watcher; on other hosts it uses a healthy Watchman installation and explicitly falls back when Watchman is missing or broken. Cloud sync and indexing can still emit dependency metadata events without changing module contents, so OnRamp suppresses only HMR cycles whose calculated delta has no added, modified, or deleted modules. Real source edits continue to use Fast Refresh normally. If refresh behavior remains unexpected, run onramp ios --watch-diagnostics; OnRamp will print each relevant source event with its exact project-relative path.

On macOS, onramp ios delegates the frontend launch to onramp-js. It adds the iOS project if it is missing, checks Xcode and CocoaPods, installs Pods, and checks Apple's preferred compatible Simulator runtime build on every launch. OnRamp asks before downloading a missing or newer runtime through Xcode, requests the exact build for the host architecture, and retries Xcode's latest compatible runtime when necessary. A failed optional upgrade continues with an installed usable runtime. When Xcode rejects both download forms, OnRamp suppresses that exact failed build combination for 24 hours while continuing to check changed Xcode or runtime metadata immediately. If Xcode itself is absent, OnRamp can open its Mac App Store page after permission, but Apple requires the user to complete the Xcode installation.

onramp android delegates the frontend launch to onramp-js. It checks Google's stable package list on every launch and asks before installing or upgrading the Android Emulator, its stable system image, or a reusable virtual device. It can bootstrap verified current Android command-line tools when the installed sdkmanager is missing or obsolete. When Google's installer prints only a download URL, OnRamp displays byte progress and then reports extraction while the official Android CLI retains responsibility for installation and verification. OnRamp gives that CLI an explicit native host platform, preventing a translated CLI executable from installing an Emulator for the wrong CPU architecture. On macOS it checks the installed Emulator binary and offers to replace a mismatched copy for the native architecture. After permission, it removes only the incompatible Emulator package, installs the native package, and verifies the resulting executable; AVDs and system images remain untouched. New AVDs use an explicit modern Pixel profile. OnRamp detects generic low-resolution devices, asks before creating a sharper replacement from the installed system image, preserves the old device and its app data, and prefers the sharper matching AVD. App installation explicitly targets the selected emulator even if another device remains online. Provider URL or checksum mismatches are failures even when the provider exits with status zero. Emulator processes that exit during startup report their own diagnostics immediately instead of appearing to hang until the boot timeout. OnRamp selects JDK 17, enables macOS clipboard sharing, cold-starts the selected AVD without the boot animation, targets only its active CPU architecture during native builds, and wakes it automatically. These settings apply only to the frontend process, so no shell profile editing is required.

Native Home navigation resets the route stack to the generated root. Home controls on ordinary and not-found screens use the shared navigation layer and do not depend on browser globals.

Native application identity is configured once in build/app.json. On every native add or run, OnRamp synchronizes the human display name, Android application ID and version, iOS bundle ID and version, and a validated 1024×1024 PNG launcher icon. Native identifiers remain stable and separate from human-facing names.

Apps that need device-only secret storage can opt into onramp-js/secure-storage by installing react-native-keychain inside build/. The adapter selects non-cloud, device-only iOS Keychain protection and Android Keystore-backed storage and refuses to fall back to browser storage.

Repair iOS dependencies while preserving the resolved versions:

onramp repair:ios

Use onramp repair:ios --fresh only when you deliberately want to remove Podfile.lock and resolve native dependency versions again.

Upgrade an existing project

OnRamp records the project schema, Python version, frontend version, React Native version, and framework-managed file bases in .onramp/project.toml. Inspect an upgrade before changing anything:

onramp upgrade --check

The check prints the complete non-mutating upgrade plan and ends with a clear verdict explaining whether the upgrade should be successful.

Apply the latest release, or select one explicitly:

onramp upgrade
onramp upgrade --to 0.5.13

The upgrader downloads a newer OnRamp release into a temporary environment when necessary, runs each project-schema migration in order, updates Python and npm metadata structurally, and saves changed files under .onramp/backups/. Unchanged framework files update automatically. A managed file edited by the application developer is never overwritten; the upgrade stops and reports the conflict instead. Native projects remain lazy and are not rebuilt merely to upgrade project metadata. Platform route registries are generated separately for iOS, Android, and web so simultaneous mobile runs do not overwrite shared route state. Route discovery and matching stay identical across targets: web retains route-level dynamic imports, while native route modules are included in Metro's initial graph to avoid development-bundle Fast Refresh loops.

Generated projects depend on a compatible release line such as onramp~=0.5.13. Patch releases remain compatible with that project schema; minor releases may introduce a schema migration handled by onramp upgrade.

The OnRamp App Framework Philosophy

Goal Enable one person, with one Python codebase, to create an app that can run on any platform and scale from a startup to an enterprise

Design Considerations Python on Everything Python is a general-purpose programming language – therefore you should be able to use it to do anything a computer can do without needing to know another general-purpose programming language. There is no reason a Python developer should have to learn JavaScript to interact with web technologies – this is the perfect job for a compiler. OnRamp will allow programmers to create apps that run anywhere knowing only Python.

HTML and CSS are the Universal UI Primitives With the advent of React Native, web technologies (HTML and CSS) are the universal primitives of UI design. Therefore, a Python web framework should not abstract away HTML and CSS. As much as possible, syntax should be the same, no matter which platform you are writing for. One possibility would be to use React Native for Web, which uses native mobile primitives (such as

Write Once, Run Anywhere React Native allows us to use a popular web framework to create apps that will run on the web, as mobile apps, and even as TV or virtual reality apps. The Python ecosystem should take advantage of this technology.

Client-First Client-first patterns provide the maximum amount of responsiveness, flexibility, and privacy necessary for the kinds of modern applications that the OnRamp project seeks to enable. Projects such as htmx have breathed new life into server-first patterns (which are similar to, but not the same as, hypermedia-driven apps), and naturally languages like Python, which due to the nature of the web and mobile platforms are more at home on the server than the client, work well with server-first frameworks. However, for the goal of OnRamp, a client-first approach is more appropriate (the only exception being if the user wants to only create an API). The challenge of getting Python into browsers and into phones is merely a technical one: Python can be compiled into JavaScript, React Native can handle the compilation into native code.

Don’t Hide Inherent Complexity Creating server-client apps involves some inherent complexity. The programmer should never be unaware about whether their code will be running on the server or the client – that level of magic leads to confusion. Although the OnRamp programmer will not need to create two parallel apps themself, the server-client divide will be clear to the experience OnRamp programmer.

Gradual Typing OnRamp should take full advantage of Python’s type hints, but the user should not need to use types to create a fully functional OnRamp app.

Async by Default Modern applications are async by default and so is OnRamp. OnRamp uses Starlette as the backend API webserver and Tortoise as the ORM, both of which are async libraries.

Batteries-Included OnRamp should include everything that you need to build a universal app, including auth. OnRamp apps should be easy to customize, but there should be an obvious OnRamp way of doing things, so that the beginning programmer can focus on the business logic of their app, not architectural decisions.

New Programmers are First-Class Citizens The developer experience of new OnRamp programmers takes precedence over power users.

Specific Design Considerations

The long-term goal is for the onramp-js React Native frontend to be written in Python and transpiled into React Native code. This is why the frontend lives in a build directory. In the current phase, however, build/ is frontend source and must be edited and committed directly. app/ remains Python backend source; there is not yet a Python-to-frontend compiler or an app/components frontend source tree.

Frontend Generator

The React Native frontend generator lives in the onramp-js directory and is published as the onramp-js npm package. The Python onramp new command invokes the compatible pinned version of that package to create the completed React Native app in the project's build directory.

When developing OnRamp from this repository, the Python CLI automatically uses the local onramp-js source. onramp-js/ is a separate Git repository and is ignored by the parent Python repository, so inspect and commit both worktrees separately. An installed OnRamp Python package uses the onramp-js version specified in src/onramp/config.toml.

The generator can also be invoked directly. This creates a web-ready app in myapp/:

npx onramp-js create myapp

Native projects can be added later:

cd myapp
npx onramp-js add ios
npx onramp-js add android
npx onramp-js add mobile

The standalone package also checks and runs each platform:

npx onramp-js doctor ios
npx onramp-js doctor android
npx onramp-js run web
npx onramp-js run ios
npx onramp-js run android

When invoked by the Python CLI, the generator prints the corresponding onramp commands instead of suggesting or describing internal npm/npx commands.

Contributing

The repository-level AGENTS.md documents the two-repository workflow and the generated-project invariants for humans and coding agents.

Run the Python tests with:

uv sync --extra dev
uv run --extra dev pytest

Run the frontend-generator tests separately:

cd onramp-js
npm test