Data internal to the add-on that it can use to initialize itself. Useful for communicating application-specific state to users joining the activity that cannot be stored in the URLs. The length of this string must be less than 4,096 characters.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-27 UTC."],[],[],null,["# Interface ActivityStartingState\n\nStarting state of the add-on when the participant accepts the invitation to\nstart an activity.\n\nSignature\n---------\n\n interface ActivityStartingState\n\nProperty signatures\n-------------------\n\n| Name | Description |\n|-------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| [`additionalData`](./addon_sdk.activitystartingstate.additionaldata.md) | Data internal to the add-on that it can use to initialize itself. Useful for communicating application-specific state to users joining the activity that cannot be stored in the URLs. The length of this string must be less than 4,096 characters. |\n| [`mainStageUrl`](./addon_sdk.activitystartingstate.mainstageurl.md) | The URL that the main stage opens for users joining the activity. The length of this URL must be less than 512 characters. |\n| [`sidePanelUrl`](./addon_sdk.activitystartingstate.sidepanelurl.md) | The URL that the side panel opens for users joining the activity. The length of this URL must be less than 512 characters. |"]]
