Osy#the first language built for agents
Agents firstAgentic appsWorkflowsDurable Execution — built inSecurityTestingThe editorThe UI modelOne program

Reference

Project

9 pages.

Deploying while workflows are running

A workflow run can outlive the deploy that started it. Deploying with --new-version freezes the code and data shape the running app has, so runs…

Hosting an Osy# app

You never set up a database. You never started a web server. That wasn't a step we skipped — it's the product. Your app is two things and you only…

How an Osy# app works (the execution model)

Read this before you write anything. An Osy# app is ONE model — you do not build an API for it, and you do not write the layers you are probably…

Moving runs onto the version you just deployed

Deploying a new version does not move the runs already in flight — they keep executing the version they started under. migrate moves them forward…

Osyrin, the runtime

Osy# is the language. Osyrin is the runtime it executes on, and it is the half of your app you did not write. This is what it holds itself to — six…

Renaming and removing things that hold data

Renaming an entity or property, and removing one, are changes to something that already holds rows. Say what you meant in a migration and the rename…

Stopping runs after a bad deploy

A workflow run keeps executing the version it started under, which is exactly what you want until that version is the problem. cancel-runs stops…

app.osy

The manifest at the root of every project. It names the app, says which files are model, seed, migrations and tests, and declares the capabilities…

project layout

The shape of an Osy# project — a manifest at the root, and folders for model, seed, migrations and tests. What you put where decides what gets…