Introduction to the Relationship Chain System

Instant Messaging (IM) can host user relationship chains and offers a complete set of relationship chain solutions. If you do not want to develop or maintain friend relationships for your app users but need features like adding and deleting friends, then you should use IM’s relationship chain hosting service.

• IM can store relationship chains, ensuring that your data has remote disaster recovery, multi-region deployment, and auto-scaling capabilities. This frees you from complex processing flows, such as server downtime, multi-copy master-slave replication, and capacity expansion and reduction.
• IM provides business processing flows that are commonly used in the industry, with which you do not have to worry about relationship chain logic.
• IM provides professional operation processes and teams, ensuring 99.99% annual service quality stability and helping you offer services known for their stability.
• IM provides easy-to-use service APIs and easy-to-access guidelines, with premium services throughout the whole process.

A relationship chain is a set of data used to describe the relationships between one user and other users. The relationship chains supported by IM include friend lists and blocklists.

Relationship Chain Fields

The IM relationship chain system supports standard and custom relationship chain fields. Relationship chain fields have the following features:

• Relationship chain fields are displayed in key-value format.
• Key is in String format, and its name can only contain uppercase and lowercase letters, numbers, and underscores.
• Value has the following types:
   a. An integer of uint64_t type (not supported for custom relationship chain fields).
   b. A string of string type (the length of string cannot exceed 500 bytes.)
   c. A buffer of bytes type (the length of buffer cannot exceed 500 bytes.)
   d. A string array of string type (the length of each string cannot exceed 500 bytes, and this type is used only for the Tag_SNS_IM_Group field of a friend list.)

Friend Lists

Users can add up to 3,000 friends to their friend lists in IM.
Friend lists support standard friend fields and custom friend fields.

Standard friend fields

Currently, IM supports the following standard friend fields:

Custom friend fields

Custom friend fields are the friend data set by each app based on its own business needs. By using custom friend fields, an app can add additional data to friends and perform read and write operations through existing APIs.
To apply for custom friend fields, the app admin can log in to IM Console and choose App Configuration > Feature Configuration. After the application is submitted, custom friend fields will take effect in 5 minutes.

The naming requirements for custom friend fields are as follows:

• The name of a custom friend field is divided into two parts: prefix and keyword.
• The prefix of a custom friend field is: Tag_SNS_Custom.
• Keyword: The keyword must be a string of letters with a length less than 8 bytes. We recommend that you use an English word or its abbreviation as the keyword.
• Example: if the custom friend field to be applied for by an app has the keyword Test, the name of the custom friend field is: Tag_SNS_Custom_Test.

When applying for custom friend fields, you need to submit the following information for each custom friend field:

• The name of the custom friend field (Key).
• The type of the custom friend field (Value). For more information, see Relationship Chain Fields.

Adding friends

IM supports the following modes for adding friends: adding friends in batches, no approval required, and approval required.

Two-way friends: user A's friend list contains user B, and user B's friend list contains user A.
One-way friend: user A's friend list contains user B, but user B's friend list does not contain user A.
Friend request approval method: each user can choose the way in which they are added as a friend of other users.
No approval required: if the approval method for friend requests set by account A is AllowType_Type_AllowAny, then anyone who wants to add account A as a friend can directly add it. In this scenario, the friend request and acceptance process has one step.
Approval required: if the approval method for friend requests set by account A is AllowType_Type_NeedConfirm, then for anyone who wants to add account A as a friend, account A will receive a message asking it to approve the new friend request. Then, account A accepts or rejects the request to complete the process. In this scenario, the friend request and acceptance process has two steps.

Deleting friends

IM supports two modes for deleting friends: one-way deletion and two-way deletion.

IM also supports deleting friends in batches.

Pulling friends

IM supports the following three modes for pulling friends: incremental pulling without friends, full pulling by page, and pulling with friends.

Verifying friends

IM supports two friend verification modes: one-way friend verification and two-way friend verification.

Possible results of one-way friend verification are:

Possible results for two-way friend verification are:

Blocklists

Each user has a blocklist, which is used to store the accounts blocked by this user.
After user A adds user B to the blocklist, user A will unfriend user B (if they are friends), and users A and B cannot send friend requests to each other in the future.
By default, you can add up to 1,000 accounts to the IM blocklist. If you need a larger blocklist, please contact Tencent Cloud customer service.

Blocking users

IM allows you to block users in batches.

Removing users from the blocklist

IM allows you to remove users from the blocklist in batches.

Pulling blocklists

IM supports pulling a full blocklist by page.

Verifying blocklists

IM supports two blocklist verification modes: one-way verification and two-way verification.

Possible results of one-way blocklist relationship verification are:

Possible results of two-way blocklist relationship verification are: