The local loop (running your app on your own machine)

Summary#

osy is the local surface: it works on the project in front of you, needs no account and no cloud. Most of it is offline. It runs against a local platform it starts for you on demand, and the whole area is one loop — write, run, look, check.

osy launch      # create the app if missing, compile this source into it, open it
osy logs --tail # what it said — client and server lines under one correlation id
osy inspect     # what actually happened in a run, and where it faulted
osy check       # validate + lint + test, one verdict, before you ship

Description#

A compile mints a new app VERSION, and data does not carry across it. This is the fact that surprises people first: a recompile is not an edit in place, so rows you created against the previous version are not what the new one reads. Seed through the app's own functions, or Importing data, after a compile — never by expecting yesterday's data to still be there.

A local platform is a cache, not a store. Instances live under ~/.osy/instances/, each carrying its own Postgres cluster, and they are reaped: one you have not touched for a day is gone, and that is correct — losing one costs a rebuild. Listing your local platforms shows every instance on the machine and which are running; Reclaiming the disk your local platforms use is the deliberate sweep. Stopping the local platform ends the one serving this project.

Ask the platform rather than reading the compiler. Most questions about your app have a verb: Understanding your app for the resolved model, Explaining your app's security for the declared security in plain English, Reading a capability's source for what a surface offers, Reading your theme for the token vocabulary you may write, Mapping your theme onto your kits — osy kit tokens --app for what each token comes to once your kits are in it. A question you answer by reading source is a question the platform has not answered yet.

When something misbehaves, look before you reason. Seeing what happened when your code ran opens the trace and jumps to the fault; Recording a run captures one deliberately; Seeing what a page cost answers the performance question. Faults are captured even with tracing off.

The pages#

Run osy docs local for the full listing.

• The loop itself — Starting a project, The inner loop, Running a local platform, Stopping the local platform, Installing the editor extension, Upgrading the toolchain
• Getting your app running — Launching your app, Launching the page you're on, Compiling your app, Adding an account, Setting an account's password, Giving a secret its value
• Getting data in and out — Importing data, Importing a data source's schema, Running a function, Reading your data
• Building a provider — Generating the C# a native provider implements
• Looking at it — Photographing a page, Seeing what happened when your code ran, Recording a run, Seeing what a page cost, Reading what your application actually used
• Asking about it — Understanding your app, Explaining your app's security, Reading a capability's source, Reading your theme, Mapping your theme onto your kits — osy kit tokens --app
• Designing it — Looking at a reference site before you design, Finding a typeface by its character, and shipping it, Finding licence-clear photographs past the stock picks, Checking whether a theme is a stock look
• Before you ship — Checking your app, What a clean check means, Checking every project at once — osy validate --all / --affected, Checking access, Drilling your app
• Shipping it — Deploying your app to an environment · Publishing a project to Osyrin (osy link, and Publish in Studio) · Signing in to Osyrin (osyrin login)
• Housekeeping — Listing your local platforms, Reclaiming the disk your local platforms use

See also#

• The inner loop — the loop end to end, for a person and for an agent at the CLI
• Launching your app — create, compile and open in one verb
• The browser for screenshots — osy browser: what --pixels needs, installed once for every project
• Opening Studio — osy studio: describe an app in your browser and your own Claude Code builds it
• What a clean check means — what a green osy check does and does not prove