pipeline status coverage report

libkazv is a matrix client sdk built upon lager and the value-oriented design it enables.


libkazv support the following functionalities:

  • Logging in
  • Receiving room states
  • Receiving room messages
  • Receiving account data
  • Receiving presence
  • Sending messages
  • Send room state events
  • Create rooms
  • Room invites
  • Join rooms
  • Typing notifications
  • Receipts and fully-read markers
  • Leaving and forgetting rooms
  • Content repository
  • Send-to-device messages
  • E2EE (send and receive events only and attachments)
  • Banning and kicking

These functionalities are currently not supported:

  • Setting presence
  • Device management
  • Direct messages
  • Redactions
  • Room history visibility
  • Registering
  • VoIP
  • Room tagging
  • Searching
  • Room previews
  • Mentions

These functionalities may be implemented, but in a low priority:

  • Push notifications
  • Third-party invites
  • Guest access
  • Server administration
  • Event context
  • Ignoring users
  • Reporting content
  • Third party networks
  • Server notices
  • Moderation policy lists

libkazv is not planning to support these functionalities:

  • Single Sign On
  • Spaces
  • Stories

Build and Use

For Gentoo users

If you are using Gentoo, you can use tusooa-overlay to install libkazv. The dependency olm can be installed from src_prepare-overlay.


libkazv depends on lager, immer, zug, boost, nlohmann_json, olm, libcrypto++.

kazvjob also depends on cpr.

Tests also depend on Catch2.

Examples also depend on libhttpserver.


You can build libkazv through the standard CMake process:

mkdir -pv build && cd build
cmake .. -DCMAKE_INSTALL_PREFIX=/path/to/prefix
make install

libkazv offers the following CMake options:

  • libkazv_BUILD_TESTS: boolean value to specify whether to build tests
  • libkazv_BUILD_EXAMPLES: boolean value to specify whether to build examples
  • libkazv_OUTPUT_LEVEL: integral value from 0 to 100 to determine what kinds of logs are shown. Setting to 100 makes libkazv output the most debug information.
  • libkazv_INSTALL_HEADERS: boolean value to determine whether to install libkazv's headers. This is by default set to OFF when libkazv is built as a subproject.

libkazv can be incorporated into your project using CMake FetchContent(). It can also be used via find_package(libkazv). It has a few libraries you can link to:

  • libkazv::kazvall is the one that contains API call definitions and client logic. It does not, however, define how the jobs are fetched.
  • libkazv::kazvjob is a tiny library that provides async and network fetching functionalities. There is one class CprJobHandler that implements JobInterface in kazv. You can link your program to kazvjob or make up another job handler using what you choose as async and network libraries. To switch from one job handler to another, you only need to change one or two lines in your program.

    Note that you will need to add COMPONENTS job to the arguments of find_package() to use this.


Tutorial 0: Getting started with libkazv


The API documentation is available at . You can also use doxygen Doxyfile at the root directory of the repository to build docs locally. It will be generated in doc/.

You SHOULD use only the following APIs in your program:

  1. Kazv::makeSdk, Kazv::makeDefaultEncryptedSdk, Kazv::makeDefaultSdkWithCryptoRandom.
  2. Default constructor of Kazv::SdkModel.
  3. Constructors of Kazv::CprJobHandler, Kazv::AsioPromiseHandler.
  4. Kazv::Sdk, Kazv::Client, Kazv::Room, but not their constructors.
  5. Kazv::LagerStoreEventEmitter.
  6. The classes that are required to interact with (e.g. return type or argument of) the classes in 4 and 5 (e.g. Kazv::Event).

Anything in the kazvapi module (i.e. the namespace Kazv::Api) is not meant to be used directly.

You should not rely on the return type of a function if it is declared as auto (without trailing return type notation). If it returns auto, you should also use auto to store that the return value.

If the documented return type is a using declaration in that class, you should either use auto or the exact alias (not the aliased type) for that. For example, in Client, a lot of functions return Client::PromiseT, so you should use auto or Client::PromiseT to refer to the return type.


The following versioning strategies are used:

  1. There are two versions in this library:
    • Package version, specified by libkazv_VERSION_STRING in CMakeLists.txt , in the format of X.Y.Z. X, Y, Z are called Major, Minor, and Patch Versions respectively.
    • so version, specified by libkazv_SOVERSION in CMakeLists.txt .
  2. When there is a new release, the versions are determined by the following rules:

    1. If there are no changes to any of the public headers (headers containing public APIs) existing in the last release, keep Major and Minor Versions as the same, increase Patch Version by 1, and keep so version as the same.
    2. If 2.1 does not hold, and all possible source code invoking only public APIs in the last release according to the guidelines (e.g. always use auto when specified) that compiles under a certain GCC version will still compile under that GCC version, keep Major Version as the same, increase Minor Version by 1, let Patch Version be 0, and increase so version by 1.
    3. Otherwise, increase Major Version by 1, let Minor and Patch Versions be 0, and increase so version by 1.

    A tldr but inaccurate version of the rules: If the new release is binary-compatible with the last one, bump Patch Version; if the new release is not binary-compatible but source-compatible with the last one, bump Minor Version and so version, reset Patch Version; otherwise, bump Major Version and so version, reset Minor and Patch Versions.


libkazv uses gtad to generate the API definitions it needed. The source of the Matrix API is . The gtad configuration files and json/query serializing used in libkazv are adapted from the ones in libQuotient. libQuotient is released under GNU LGPL v2.1. The changes in said files in libkazv compared to libQuotient's are:

  • Get rid of the avoidCopy and moveOnly markers
  • Use data types from immer and std instead of Qt
  • Use nlohmann::json instead of Qt's JSON library


Copyright (C) 2020 Tusooa Zhu

libkazv is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

libkazv is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with libkazv. If not, see