API & Architecture
Verified against source (7)
Config/CustomRoutes.configapplication/QboRouteHandler.csapplication/HttpAsyncHandler.csapplication/AbstractObject.csInterfaces/IQueue.csInterfaces/IService.cssrc/QueueService
QBO is API-first. Every screen in QBO calls the same operations you can call from an integration, a workflow step, or a scheduled job. If you can do it in the UI, you can automate it.
- One pattern for every module. Processes, contacts, documents, messages, and workflows all respond to
/api/{module}/{operation}, with shared operations such as Save, Search, and Summary. - Run now or queue it. The same operation runs immediately on a web server, or is queued for app servers when it’s long-running, scheduled, or rate-limited.
- Extend without forking. New operations come from configuration (SQL statements, routes, service recipes) or plugins, and appear in the API, workflow, and permissions automatically.
Key concepts
Section titled “Key concepts”| Concept | In QBO | What it does |
|---|---|---|
| Operation | a method signature, {Module}/{Operation}?{parameters} |
A C# method, SQL statement, or configured service on a module. |
| Route | CustomRoute |
Maps a URL to an operation. Standard routes provide /api/{module}/{operation}. |
| Queue | IQueue |
Buffers operations for app servers, with retries, throttling, priorities, and calendars. Implementations include Amazon SQS and SQL Server Service Broker. |
| Queue Service | a Windows service on app servers | Pops queued messages and runs the operation. |
| Schedule | Schedule |
A recurrence in plain English, such as Daily at 6am or Monthly on the 2nd Sat. |
| Calendar | Calendar |
Business days, hours, and holidays that queues, schedules, and checks respect. |
| Setting | SystemDefault and application settings |
Configuration values, overridable by role or user. |
| Service | IService |
A plugin operation, such as a REST call, a recipe of operations, or custom code. |
How a request flows
Section titled “How a request flows”- A caller (a browser, an integration, or a workflow step) sends
/api/{module}/{operation}with parameters. - QBO authenticates the caller and checks the operation’s permission and row-level access (see Security).
- QBO runs the operation and returns XML, JSON, HTML, or CSV, or queues it and returns a message ID.
- Queued work runs on app servers, which scale out independently of the web tier.
Choose your view
Section titled “Choose your view”Use the buttons under the page title. Power user covers queues, schedules, calendars, settings, custom routes, health checks, and logs. Developer covers the route pattern, standard operations, save conventions, queuing from the API, and writing plugins. For the deployment picture, see Architecture.