There are multiple important terms to understand when it comes to permission management. Each permission check comes down to three things:
Subject - an actor which attempts to perform certain Action. It could be represented by a User or by a ChannelMember
Resource - an item that Subject attempts to perform an Action against. It could be a Channel, Message, Attachment or another User
Action - the exact action that is being performed. For example CreateChannel , DeleteMessage , AddLinks
The purpose of permission system is to answer a question: isSubject Aallowed to performAction BonResource C ?
Stream Chat provides several concepts which help to control which actions are available to whom:
Permission - an object which represents actions a subject is allowed to perform
Role - assigned to a User or Channel Member and is used to check their permissions
Grants - the way permissions are assigned to roles, applicable across the entire application, or specific to a single channel type or channel.
Also important to know is permissions checking only happens on the client-side calls. Server-side allows everything so long as a valid API key and secret is provided.
To make it easy to get started, all Stream applications come with several roles already built in with permissions to represent the most common use cases. These roles can be customized if needed, and new roles can be created specific for your application
This is the process of assigning a role to users so they can be granted permissions. This represents Subject A in the permissions question. Users will have one role which grants them permissions for the entire application and additionally users can have channel roles which grant permissions for a single channel or for all channels with the same channel type.
By default all users have builtin role user assigned. To change the role of the User, you can use UpdateUser API endpoint:
// This is a server-side only feature, choose any of our server-side SDKs to use it
Once you add user to the channel, channel_member role will be assigned to user's membership:
const result = await channel.addMembers([{ user_id: "james_bond" }]);console.log(result.members[0].channel_role); // "channel_member"
$result = $client->updateChannel("messaging", "channel-id", new Models\UpdateChannelRequest( addMembers: [new Models\ChannelMemberRequest(userID: "james_bond")],));
from getstream.models import ChannelMemberRequestresult = channel.update(add_members=[ChannelMemberRequest(user_id="james_bond")])print(result.data.members[0].channel_role)
var resp = chat.channel("channel_type", "channel_id") .update(UpdateChannelRequest.builder() .addMembers(List.of(ChannelMemberRequest.builder().userID("james_bond").build())) .build());System.out.println(resp.getData().getMembers().get(0).getChannelRole());
var addMembersResponse = await chat.UpdateChannelAsync("channel-type", "channel-id", new UpdateChannelRequest{ AddMembers = new List<ChannelMemberRequest> { new ChannelMemberRequest { UserID = "user-id" }, },});Console.WriteLine(addMembersResponse.Members[0].ChannelRole); // channel role is equal to "channel_member"
// This is a server-side only feature, choose any of our server-side SDKs to use it
In order to change channel-level role of the user, you can either add user to the channel with a different role (if the SDK supports it) or update it later by role assignment:
// Add user to the channel with role setawait channel.addMembers([ { user_id: "james_bond", channel_role: "channel_moderator" },]);// Assign new channel member roleawait channel.assignRoles([ { user_id: "james_bond", channel_role: "channel_member" },]);
// Add user to the channel with role set$client->updateChannel("messaging", "general", new Models\UpdateChannelRequest( addMembers: [new Models\ChannelMemberRequest(userID: "james_bond", channelRole: "channel_moderator")],));// Assign new channel member role$client->updateChannel("messaging", "general", new Models\UpdateChannelRequest( assignRoles: [new Models\ChannelMemberRequest(userID: "james_bond", channelRole: "channel_member")],));
from getstream.models import ChannelMemberRequest# Add user to the channel with role setresult = channel.update(add_members=[ChannelMemberRequest(user_id="james_bond", channel_role="channel_moderator")])# Assign new channel member roleresult = channel.update(assign_roles=[ChannelMemberRequest(user_id="james_bond", channel_role="channel_member")])
// User must be a member of the channel before you can assign channel rolevar resp = await chat.UpdateChannelAsync("channel-type", "channel-id", new UpdateChannelRequest{ AssignRoles = new List<ChannelMemberRequest> { new ChannelMemberRequest { UserID = "user-id", ChannelRole = "channel_moderator" }, },});
require 'getstream_ruby'Models = GetStream::Generated::Models# Add user to the channel with role setclient.chat.update_channel('messaging', 'channel-id', Models::UpdateChannelRequest.new( add_members: [Models::ChannelMemberRequest.new(user_id: 'james_bond', channel_role: 'channel_moderator')]))# Assign new channel member roleclient.chat.update_channel('messaging', 'channel-id', Models::UpdateChannelRequest.new( assign_roles: [Models::ChannelMemberRequest.new(user_id: 'james_bond', channel_role: 'channel_member')]))
// This is a server-side only feature, choose any of our server-side SDKs to use it
changing channel member roles is not allowed client-side.
Subject
Subject can be represented by User or ChannelMember. ChannelMember subject is used only when user interacts with a channel that they are member of. Both User and ChannelMember have Role and permission system takes both roles into consideration when checking permissions.
Some Stream Chat entities have an owner and the fact of ownership can be considered when configuring access permissions. Ownership is supported in these entity types:
Channel - owned by its creator
Message - owned by its creator (sender)
Attachment - owned by user who uploaded a file
User - authenticated user owns itself
Using ownership concept, permissions could be set up in such a way that allows entity owners to perform certain actions. For example:
Update Own Message - allows message senders to edit their messages
Update Own User - allows users to change their own properties (except role and team)
Send Message in Own Channel - allows channel creators to send messages in the channels that they created even if they are not members
In more sophisticated scenarios custom roles could be used. One Stream Chat application could have up to 25 custom roles. Roles are simple, and require only a name to be created. They do nothing until permissions are assigned to the role. To create new custom role you can use CreateRole API endpoint:
// This is a server-side only feature, choose any of our server-side SDKs to use it
In order to delete a role, you have to remove all permission grants that this role has and make sure that you don't have non-deleted users with this role assigned. Channel-level roles could be deleted without reassigning them, although, some users could lose access to channels where this role is used.
Once you have a role created you can start granting permissions to it. You can also grant or remove permissions for built in roles.
User access in Chat application is split across multiple scopes.
Application Permissions : You can grant these using the .app scope. These permissions apply to operations that occur outside of channel-types including accessing and modifying other users, or using moderation features.
Channel-Type Permissions : These apply permissions to all channels of a particular type.
Channel Permissions : These apply permissions to a single channel and override channel-type permissions.
To list all available permissions you can you ListPermissions API endpoint:
const { permissions } = await client.listPermissions(); // List of Permission objects
$response = $client->listPermissions();
response = client.list_permissions()
var response = client.listPermissions(ListPermissionsRequest.builder().build()).execute();
var response = await client.ListPermissionsAsync();
Grants action CreateMessage which allows to send a new message, user should own a channel
action
string
Action which this permission grants
CreateMessage
owner
boolean
If true, Subject should be an owner of the Resource
true
same_team
boolean
If true, Subject should be a part of the team that Resource is a part of
true
To manipulate granted permissions for certain channel type, you can use UpdateChannelType API endpoint:
// observe current grants of the channel typeconst { grants } = await client.getChannelType("messaging");// update "channel_member" role grants in "messaging" scopeawait client.updateChannelType("messaging", { grants: { channel_member: [ "read-channel", // allow access to the channel "create-message", // create messages in the channel "update-message-owner", // update own user messages "delete-message-owner", // delete own user messages ], },});
// observe current grants of the channel type$response = $client->getChannelType("messaging");// update "channel_member" role grants in "messaging" scope$client->updateChannelType("messaging", new Models\UpdateChannelTypeRequest( grants: [ "channel_member" => ["read-channel", "create-message", "update-message-owner", "delete-message-owner"], ],));
# observe current grants of the channel typeresponse = client.chat.get_channel_type(name="messaging")print(repr(response.data.grants))# update "channel_member" role grants in "messaging" scopeclient.chat.update_channel_type( name="messaging", automod="disabled", automod_behavior="flag", max_message_length=5000, grants={ "channel_member": [ "read-channel", # allow access to the channel "create-message", # create messages in the channel "update-message-owner", # update own user messages "delete-message-owner", # delete own user messages ] },)
// observe current grants of the channel typevar response = chat.getChannelType("messaging", GetChannelTypeRequest.builder().build()).execute();System.out.println(response.getData().getGrants());// update "channel_member" role grants in "messaging" scopevar grants = new HashMap<String, List<String>>();grants.put("channel_member", List.of( "read-channel", // allow access to the channel "create-message", // create messages in the channel "update-message-owner", // update own user messages "delete-message-owner" // delete own user messages));chat.updateChannelType("messaging", UpdateChannelTypeRequest.builder() .automod("disabled") .automodBehavior("flag") .maxMessageLength(5000) .grants(grants) .build()).execute();
// observe current grants of the channel typevar channelType = await chat.GetChannelTypeAsync("messaging");Console.WriteLine(channelType.Grants);// update "channel_member" role grants in "messaging" scopeawait chat.UpdateChannelTypeAsync("messaging", new UpdateChannelTypeRequest{ Grants = new Dictionary<string, List<string>> { { // This will replace all existing grants of "channel_member" role "channel_member", new List<string> { "read-channel", // allow access to the channel "create-message", // create messages in the channel "update-message-owner", // update own user messages "delete-message-owner", // delete own user messages } }, },});
require 'getstream_ruby'Models = GetStream::Generated::Models# observe current grants of the channel typeresponse = client.chat.get_channel_type('messaging')puts response.grants# update "channel_member" role grants in "messaging" scopeclient.chat.update_channel_type('messaging', Models::UpdateChannelTypeRequest.new( grants: { 'channel_member' => [ 'read-channel', # allow access to the channel 'create-message', # create messages in the channel 'update-message-owner', # update own user messages 'delete-message-owner' # delete own user messages ] }))
// observe current grants of the channel typeresp, err := client.Chat().GetChannelType(ctx, "messaging", &getstream.GetChannelTypeRequest{})fmt.Print(resp.Data.Grants)// update "channel_member" role grants in "messaging" scope_, err = client.Chat().UpdateChannelType(ctx, "messaging", &getstream.UpdateChannelTypeRequest{ Grants: map[string][]string{ "channel_member": { "read-channel", // allow access to the channel "create-message", // create messages in the channel "update-message-owner", // update own user messages "delete-message-owner", // delete own user messages }, },})
// This is a server-side only feature, choose any of our server-side SDKs to use it
This call will only change grants of roles that were mentioned in the request. You can remove all role grants with providing empty array ( [] ) as list of granted permissions:
await client.updateChannelType("messaging", { grants: { guest: [], // removes all grants of "guest" role anonymous: [], // removes all grants of "anonymous" role },});
$client->updateChannelType("messaging", new Models\UpdateChannelTypeRequest( grants: [ "guest" => [], // removes all grants of "guest" role "anonymous" => [], // removes all grants of "anonymous" role ],));
client.chat.update_channel_type( name="messaging", automod="disabled", automod_behavior="flag", max_message_length=5000, grants={ "guest": [], # removes all grants of "guest" role "anonymous": [], # removes all grants of "anonymous" role },)
var grants = new HashMap<String, List<String>>();grants.put("guest", Collections.emptyList()); // removes all grants of "guest" rolegrants.put("anonymous", Collections.emptyList()); // removes all grants of "anonymous" rolechat.updateChannelType("messaging", UpdateChannelTypeRequest.builder() .automod("disabled") .automodBehavior("flag") .maxMessageLength(5000) .grants(grants) .build()).execute();
await chat.UpdateChannelTypeAsync("messaging", new UpdateChannelTypeRequest{ Grants = new Dictionary<string, List<string>> { { "guest", new List<string>() }, // removes all grants of "guest" role { "anonymous", new List<string>() }, // removes all grants of "anonymous" role },});
require 'getstream_ruby'Models = GetStream::Generated::Modelsclient.chat.update_channel_type('messaging', Models::UpdateChannelTypeRequest.new( grants: { 'guest' => [], # removes all grants of "guest" role 'anonymous' => [] # removes all grants of "anonymous" role }))
_, err = client.Chat().UpdateChannelType(ctx, "messaging", &getstream.UpdateChannelTypeRequest{ Grants: map[string][]string{ "anonymous": {}, // removes all grants of "anonymous" role "guest": {}, // removes all grants of "guest" role },})
// This is a server-side only feature, choose any of our server-side SDKs to use it
If you want to reset the whole scope to default settings, you can explicitly provide null to grants field:
await client.updateChannelType("messaging", { grants: null, // resets the whole scope to default settings});
$client->updateChannelType("messaging", new Models\UpdateChannelTypeRequest( grants: null, // resets the whole scope to default settings));
# reset the whole scope to default settingsclient.chat.update_channel_type( name="messaging", automod="disabled", automod_behavior="flag", max_message_length=5000, grants=None,)
Stream Dashboard provides a user interface to edit permission grants. This UI is available on Chat > Roles & Permissions page which is available after switching to version 2 of permissions.
In some cases it makes sense to slightly modify granted permissions for the channel without changing channel-type grants configuration. For this, you can use Grants Modifiers that you can set for each channel individually. Grants Modifiers look almost exactly the same as regular Grants object except it allows to revoke permissions as well as grant new ones. For example, if we want to disallow sending links for users with role "user" in channel "livestream:example" and allow creating reactions, we can do this:
A common example of changing the permission model of a channel type is to create a Telegram-style broadcast channel where privileged channel members can send messages and other members may have permissions restricted to reading, reactions, or replying.
The three Permission grants to modify these under the scope of the channel type are