Progressive Server

Matrix homeserver written in C++23 — built from scratch for the Matrix ecosystem.

Overview

Progressive Server is a high-performance Matrix homeserver implemented in modern C++23. It is built from the ground up, using Synapse as the primary architectural reference, with plans to also draw from Dendrite, Conduit, and other Matrix implementations.

Why C++?

• Zero-runtime-overhead abstractions — templates, constexpr, move semantics
• No garbage collection — deterministic memory management
• Direct kernel I/O — epoll/kqueue via Boost.Asio
• Single binary deployment — static linking, minimal dependencies

Current Status

Subsystem	Status	Notes
Types	Done	Domain-specific strings, Requester, StateMap, StreamToken
Config	Done	JSON config loading, validation, listener/database setup
Events	Done	Event model, UnsignedData, Signatures, factory
JSON	Done	Canonical JSON, nlohmann integration
Storage	Done	SQLite3 + PostgreSQL backends, connection pool, schema DDL
HTTP Server	Done	Boost.Beast TCP acceptor, session handling, keep-alive
Router	Done	Regex URL routing, path params, CORS, JSON responses
Auth	Done	SHA-256 passwords, access tokens, registration
Client/Server API	Done	/versions, /login, /register, /whoami, /createRoom, /sync
Federation	Done	/send, /event, /state, /make_join, /send_join, /query, X-Matrix auth
Key Server	Done	/_matrix/key/v2/server
State Resolution	Done	V1 (phase-ordered) + V2 (iterative auth checks, topological sort)
Room Versions	Done	v1–v11 with auth properties
Push Rules	Done	26 base rules, glob matcher, evaluator
Auth Rules	Done	auth_types_for_event, check_state_dependent_auth_rules
Ed25519	Stub	Signing infrastructure in place, real EVP signing pending
Media	Pending	Upload/download endpoints
E2EE	Pending	Key backup, device management

Building

Prerequisites

• CMake 3.22+
• C++23 compiler (GCC 14+, Clang 18+)
• Boost 1.84+ (URL, JSON)
• OpenSSL 3+
• SQLite3 or PostgreSQL

Build

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build -j$(nproc)

Run

# Generate config
./build/src/progressive-server --generate-config > homeserver.yaml

# Start server
./build/src/progressive-server -c homeserver.yaml

Tests

cmake -B build -DCMAKE_BUILD_TYPE=Release -DPROGRESSIVE_BUILD_TESTS=ON
cmake --build build -j$(nproc)
cd build && ctest --output-on-failure

Architecture

Client ──HTTP──> Beast Acceptor ──> Router ──> REST Servlets
                                                   │
                                          ┌────────┼────────┐
                                          ▼        ▼        ▼
                                        Auth    Storage   Federation
                                          │        │        │
                                          └────────┼────────┘
                                                   ▼
                                            SQLite / PostgreSQL

Stack

• I/O: Boost.Asio + Boost.Beast (HTTP/1.1)
• JSON: nlohmann/json
• Crypto: OpenSSL
• Database: SQLite3 (dev/test), PostgreSQL (production)
• Build: CMake + Ninja
• CI: GitHub Actions — Ubuntu 24.04/latest, macOS, Clang 18-20

References

Built with architectural reference from:

• Synapse — the reference Matrix homeserver (Python)
• Dendrite — second-generation Matrix homeserver (Go)
• Conduit — lightweight Matrix homeserver (Rust)

License

To be determined. Currently all rights reserved.