> ## Documentation Index > Fetch the complete documentation index at: https://cometchat-013b37f0.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Properties And Constraints This page lists the properties and limits which are applicable to various CometChat systems. ## **Chat widgets:** **Properties and Constraints** | **Item** | **Property or Constraint** | **Notes** | | ------------------------------------------------ | ------------------------------------------ | ----------------------------- | | Number of Widgets that can be created for an app | Maximum 25 | | | Widget name | UTF8mb4, 100 chars, No new line characters | | | Widget version | v2 | Cannot be set programatically | | Docked layout icon | Docked layout icon: PNG,JPG,GIF,SVG | | ## **Webhooks: Properties** **and Constraints** | **Item** | **Property or Constraint** | **Notes** | | ------------------------------------ | --------------------------------------------------------- | --------- | | Maximum number of webhooks in an app | Maximum 25 | | | Webhook URL | Valid URL, maximum 255 characters | | | Webhook ID | 50 characters, UTF8mb4 set, alphanumeric (without spaces) | | | Webhook authentication username | 50 characters, alphanumeric (without spaces) | | | Webhook authentication password | 100 characters, alphanumeric (without spaces) | | ## **Management APIs:** **Properties and Constraints** | Item | Property or Constraint | Notes | | ------------------------------------------------------------- | --------------------------- | --------------------------------- | | App length | 100 characters, UTF8mb4 set | | | App version | v3 | This is the only option available | | Number of Collaborators that can be created (team management) | Maximum 25 | | **REST APIs:** **Properties** **and Constraints** Also see REST API documentation for further information on properties and constraints for each endpoint. | **Item** | **Property or Constraint** | **Notes** | | -------------------------------------------------- | ----------------------------------- | ------------------------------------------------------------------------------- | | Number of Bot users that can be created | Maximum 25 | | | API Keys | 100 characters (UTF8mb4 Characters) | This covers all the languages and even emojis. (One emoji uses two characters). | | Number of APIs keys that can be created for an app | Maximum 25 | | ## **Users and Groups:** **Properties and Constraints** | **Item** | **Property or Constraint** | **Notes** | | ------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------ | | Character limits for UIDs and GUIDs | 100 characters | | | Maximum users in a group (v3) | 100000 | | | Maximum groups a user can be a part of | No limits | | | Maximum number of friends for a user | No limits | | | Maximum tokens for a user | No limits | | | Maximum number of groups | No limits | | | Maximum number of unread messages per user | No limits | | | Maximum number of users that can be created for an app | No limits | | | User and Group ID | 100 characters, alpha-dash (a-z, 0-9 with -and \_) without spaces . | CometChat forces the UID to all lowercase. | | User and Group name | 100 characters, UTF8mb4 set | This covers all the languages and even emojis. | | User and Group avatar | Must be a URL, limit of 3000 characters | CometChat doesn’t save the image on its servers.. There is no limit on the image resolution. It depends on the implementation. | | User profile | Must be a URL, limit of 3000 characters | Same as above | | User and Group metadata | The API limit for the POST request length is 10 KB. Hence, the user’s metadata information must fit in the same limit and must not exceed 1.6 KB. | | | User and Group tag | A user can have up to 25 tags with 100 characters per tag. The tags can be in any language. The character set must be UTF8mb4 | | | Group password | String up to 100 characters | | | Group description | 255 characters, UTF8mb4 set | | | Maximum active presence subscriptions | The presence subscription will be active until 1000 users are online for a single app. if more than 1000 users go online, the presence notification starting from the 1001st user will not be sent to other users. | Note, this is the higher limit applicable across subscription for friends, users with certain roles and all users | | Typing indicators for groups | Typing indicator will be sent for a group of up to 1000 online users. | | | Unread message counts for groups | For a group with more than 300 members, the conversations and unread message counts are not updated. | | | Delivery and read receipts for groups | Delivery and read receipts will be sent for for a group of up to 300 online users. | | ## **Roles: Properties and Constraints** | **Item** | **Property or Constraint** | **Notes** | | ------------------------------------------- | ----------------------------------------------------------------- | ---------------------------------------------- | | Maximum number of Roles that can be created | Maximum 25 | | | Role UID | 100 characters, alpha-dash (a-z, 0-9 with -and \_) without spaces | CometChat forces the UID to lowercase. | | Role name | 100 characters, UTF8mb4 | This covers all the languages and even emojis. | | Role description | 255 characters, UTF8mb4 set, any language. | | | Metadata | No limit | | ## **Messages: Properties and Constraints** | **Item** | **Property or Constraint** | **Notes** | | -------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------- | | Maximum file attachment size | 100 MB per message | (Includes not just the file size but entire POST body (including chat text and custom data) | | Message data (Applicable for API calls) | Data is an arbitrary JSON structure. It accepts utf8mb4. It can have any user defined properties. but the below properties have meaning for CometChat: text, attachments, custome\_data, metadata. Note: The attachment size is separate. Here, the attachment is only the attachment properties (such as URL, size, etc.). The size must not exceed 10KB for the data object. | | | Message tags | A message can have up to 25 tags with 100 characters per tag. The tags can be in any language. The character set must be UTF8mb4. | | | User and Group conversation tags | A conversation can have up to 25 tags with 100 characters per tag. The tags can be in any language. The character set must be UTF8mb4. | | | Does CometChat keep soft deleted messages in its database? | Yes | | | Does CometChat keep permanently deleted messages (by API) in its database? | No | | ## **Calling: Properties and Constraints** | **Item** | **Property or Constraint** | **Notes** | | ---------------------------------- | ------------------------------ | --------------------------------------------------------------------------------- | | Maximum users in a call | 50 | | | Default frame rate for video calls | 30 FPS | | | Resolution for video calls | Maximum - 720p, Minimum - 180p | This depends on the layout selected and the bandwidth available at the user’s end | | Media encryption used | SRTP | | | Audio codec used | OPUS | | | Video codec used | H.264 | |