Developing Plugins

This guide covers how to build your own HappyView WASM plugins. For installing and configuring plugins, see the Plugins guide.

See the happyview-plugins repository for examples and the plugin SDK.

Plugin Manifest

Each plugin has a manifest.json that describes its metadata:

{
  "id": "steam",
  "name": "Steam",
  "version": "1.0.0",
  "api_version": "1",
  "description": "Import your Steam game library and playtime data.",
  "icon_url": "https://example.com/steam-icon.png",
  "auth_type": "openid",
  "wasm_file": "steam.wasm",
  "required_secrets": [
    {
      "key": "PLUGIN_STEAM_API_KEY",
      "name": "Steam Web API Key",
      "description": "Get your API key at steamcommunity.com/dev/apikey"
    }
  ]
}

Field	Description
`id`	Unique plugin identifier
`name`	Display name
`version`	Semantic version
`api_version`	Plugin API version (currently “1”)
`description`	Brief description shown during install
`icon_url`	Optional icon URL
`auth_type`	Authentication type: `oauth2`, `openid`, or `api_key`
`wasm_file`	WASM binary filename (default: `plugin.wasm`)
`required_secrets`	Array of secrets the plugin needs

API Endpoints

Public Endpoints

Endpoint	Description
`GET /external-auth/providers`	List available auth providers
`GET /external-auth/accounts`	List user’s linked accounts
`GET /external-auth/{plugin}/authorize`	Start OAuth flow
`GET /external-auth/{plugin}/callback`	OAuth callback handler
`POST /external-auth/{plugin}/sync`	Sync data from linked account
`POST /external-auth/{plugin}/unlink`	Unlink account
`POST /external-auth/{plugin}/connect`	Connect with API key (for `api_key` auth type)

Admin Endpoints

Endpoint	Description
`GET /admin/plugins`	List installed plugins
`POST /admin/plugins`	Install a plugin
`POST /admin/plugins/preview`	Preview plugin before installing
`GET /admin/plugins/official`	Browse the official plugin registry catalog
`DELETE /admin/plugins/{id}`	Remove a plugin
`POST /admin/plugins/{id}/reload`	Reload plugin from source
`POST /admin/plugins/{id}/check-update`	Check whether a newer version is available
`GET /admin/plugins/{id}/secrets`	Get configured secrets (masked)
`PUT /admin/plugins/{id}/secrets`	Update plugin secrets

The dashboard’s Settings > Plugins page calls GET /admin/plugins/official to populate the install browser, and POST /admin/plugins/{id}/check-update to display update badges on installed plugins.

Plugin Exports

Plugins must export these functions:

Export	Signature	Description
`alloc`	`(size: u32) -> u32`	Allocate memory
`dealloc`	`(ptr: u32, size: u32)`	Deallocate memory
`get_authorize_url`	`(ptr: u32, len: u32) -> i64`	Generate OAuth authorize URL
`handle_callback`	`(ptr: u32, len: u32) -> i64`	Handle OAuth callback
`refresh_tokens`	`(ptr: u32, len: u32) -> i64`	Refresh expired tokens
`get_profile`	`(ptr: u32, len: u32) -> i64`	Get external profile info
`sync_account`	`(ptr: u32, len: u32) -> i64`	Sync data and return records

Host Functions

Plugins can import these host functions:

Import	Description
`host_http_request`	Make HTTP requests
`host_get_secret`	Read configured secrets
`host_log`	Write to server logs
`host_kv_get`	Read from KV storage
`host_kv_set`	Write to KV storage
`host_kv_delete`	Delete from KV storage

Next steps

Official plugins repository — ready-to-use plugins and the plugin SDK
Plugins guide — install and configure plugins
API Keys — authenticate programmatic access to admin endpoints
Permissions — configure user access to plugin management