Canvas Extensions API

Build and validate OpenHands Apps with the Canvas Extensions API, targeting the currently implemented manifest schema 1 and host API 1 routed-page ABI.

Use the naming layers consistently:

• OpenHands Apps - customer-facing category for interfaces people discover, install, enable, and open.
• Apps for Agent Canvas - product phrasing that clarifies where apps run.
• Canvas Extensions API - developer platform used to build apps.
• Canvas extension package - technical artifact containing canvas-extension.json and its entrypoint.
• OpenHands Extensions - ecosystem and repository umbrella for apps, skills, plugins, automations, and integrations.

Use current product labels in user-facing instructions: Apps for Agent Canvas, Add app, Installed apps, App source, Enable trusted app, and Build an app. Keep technical identifiers such as canvas-extension.json, /api/canvas-extensions/*, host.extension, and /extensions/* unchanged unless the target implementation changes them.

Treat apps as trusted, same-realm browser code owned by the active Agent Server. Keep the categories distinct: apps extend what people can do in Agent Canvas, plugins extend agent runtime capabilities, and skills provide agent instructions and knowledge.

Prefer the proven App authoring loop