Apps | Nimbus

Feature	Feature status	claude	codex	cursor
`future-companion-source-pointers`	`planned`	`planned`	`planned`	`planned`
`plugin-apps`	`implemented`	`not_applicable`	`pass_through`	`planned`

Support vocabulary: Feature Reference

The Codex-selected ChatGPT product bundle can include an .app.json app declaration. Skillset resolves the conventional file as typed OpenAI component source for rendering, provenance, and activation planning; there is no user-facing feature-key source pointer.

Authoring

Place .skillset/plugins/<plugin>/.app.json in plugin source when an enabled Codex target should include the ChatGPT app component. It renders at plugins/<plugin>/.app.json and is referenced by extensions.com.openai.apps. Discovery is automatic. There is no apps.source, app.source, or apps: true source key; those shapes fail config validation.

.skillset/plugins/reviewer/.app.json

Target Rendering

Source	Claude output	Codex output	Status	Notes
`.app.json`	n/a	`.app.json` plus `extensions.com.openai.apps`	`target_native` / `implemented`	Opaque pass-through today.
Future `apps.source`	n/a	n/a	`planned`	Reserved for a later adapter if app manifests need feature-key validation and provenance.

Diagnostics

Unknown top-level plugin config keys fail, so unsupported apps.source syntax is not silently accepted.
App manifest pass-through does not install, activate, trust, or mutate Codex runtime configuration.
If provider source tries to emit a conflicting .app.json, divergent output detection fails loudly.

Provenance

The current .app.json pass-through participates in plugin output hashes, generated manifest shape, and the plugin-feature lock entry used for activation planning.

Evidence

The Codex provider reference records the provider boundary. Plugin manifest and contract tests verify companion discovery, conflicts, and generated manifest shape.