abus

A D-Bus implementation in Rust, built specifically for Tokio.

Most of the existing Rust D-Bus work supports multiple async runtimes. That flexibility is useful if you need it, but it comes with a real cost: a larger dependency surface, extra abstraction layers, and a library that doesn't quite fit anywhere. abus skips all of that. Tokio only, nothing else.

Note: abus is under active development. The roadmap below describes what this project is working toward, not what is necessarily implemented today.

Why

The difference is most obvious in the dependency trees. Here are the non-dev, default-feature trees for both:

abus 0.0.1

abus v0.0.1
├── bytes v1.11.1
├── getrandom v0.4.2
│   ├── cfg-if v1.0.4
│   └── libc v0.2.183
├── itoa v1.0.17
├── rustix v1.1.4
│   ├── bitflags v2.11.0
│   └── linux-raw-sys v0.12.1
├── serde_core v1.0.228
├── tokio v1.50.0
│   ├── bytes v1.11.1
│   ├── libc v0.2.183
│   ├── mio v1.1.1
│   │   └── libc v0.2.183
│   ├── pin-project-lite v0.2.17
│   └── socket2 v0.6.3
│       └── libc v0.2.183
└── tracing v0.1.44
    ├── pin-project-lite v0.2.17
    ├── tracing-attributes v0.1.31 (proc-macro)
    │   ├── proc-macro2 v1.0.106
    │   │   └── unicode-ident v1.0.24
    │   ├── quote v1.0.45
    │   │   └── proc-macro2 v1.0.106 (*)
    │   └── syn v2.0.117
    │       ├── proc-macro2 v1.0.106 (*)
    │       ├── quote v1.0.45 (*)
    │       └── unicode-ident v1.0.24
    └── tracing-core v0.1.36
        └── once_cell v1.21.4

zbus 5.14.0

zbus v5.14.0
├── async-broadcast v0.7.2
│   ├── event-listener v5.4.1
│   │   ├── concurrent-queue v2.5.0
│   │   │   └── crossbeam-utils v0.8.21
│   │   ├── parking v2.2.1
│   │   └── pin-project-lite v0.2.16
│   ├── event-listener-strategy v0.5.4
│   │   ├── event-listener v5.4.1 (*)
│   │   └── pin-project-lite v0.2.16
│   ├── futures-core v0.3.32
│   └── pin-project-lite v0.2.16
├── async-executor v1.14.0
│   ├── async-task v4.7.1
│   ├── concurrent-queue v2.5.0 (*)
│   ├── fastrand v2.3.0
│   ├── futures-lite v2.6.1
│   │   ├── fastrand v2.3.0
│   │   ├── futures-core v0.3.32
│   │   ├── futures-io v0.3.32
│   │   ├── parking v2.2.1
│   │   └── pin-project-lite v0.2.16
│   ├── pin-project-lite v0.2.16
│   └── slab v0.4.11
├── async-io v2.6.0
│   ├── cfg-if v1.0.4
│   ├── concurrent-queue v2.5.0 (*)
│   ├── futures-io v0.3.32
│   ├── futures-lite v2.6.1 (*)
│   ├── parking v2.2.1
│   ├── polling v3.11.0
│   │   ├── cfg-if v1.0.4
│   │   └── rustix v1.1.4
│   │       ├── bitflags v2.10.0
│   │       └── linux-raw-sys v0.12.1
│   ├── rustix v1.1.4 (*)
│   └── slab v0.4.11
├── async-lock v3.4.2
│   ├── event-listener v5.4.1 (*)
│   ├── event-listener-strategy v0.5.4 (*)
│   └── pin-project-lite v0.2.16
├── async-process v2.5.0
│   ├── async-channel v2.5.0
│   │   ├── concurrent-queue v2.5.0 (*)
│   │   ├── event-listener-strategy v0.5.4 (*)
│   │   ├── futures-core v0.3.32
│   │   └── pin-project-lite v0.2.16
│   ├── async-io v2.6.0 (*)
│   ├── async-lock v3.4.2 (*)
│   ├── async-signal v0.2.13
│   │   ├── async-io v2.6.0 (*)
│   │   ├── cfg-if v1.0.4
│   │   ├── futures-core v0.3.32
│   │   ├── futures-io v0.3.32
│   │   ├── rustix v1.1.4 (*)
│   │   └── signal-hook-registry v1.4.7
│   │       └── libc v0.2.183
│   ├── async-task v4.7.1
│   ├── cfg-if v1.0.4
│   ├── event-listener v5.4.1 (*)
│   ├── futures-lite v2.6.1 (*)
│   └── rustix v1.1.4 (*)
├── async-recursion v1.1.1 (proc-macro)
│   ├── proc-macro2 v1.0.106
│   │   └── unicode-ident v1.0.22
│   ├── quote v1.0.45
│   │   └── proc-macro2 v1.0.106 (*)
│   └── syn v2.0.117
│       ├── proc-macro2 v1.0.106 (*)
│       ├── quote v1.0.45 (*)
│       └── unicode-ident v1.0.22
├── async-task v4.7.1
├── async-trait v0.1.89 (proc-macro)
│   ├── proc-macro2 v1.0.106 (*)
│   ├── quote v1.0.45 (*)
│   └── syn v2.0.117 (*)
├── blocking v1.6.2
│   ├── async-channel v2.5.0 (*)
│   ├── async-task v4.7.1
│   ├── futures-io v0.3.32
│   ├── futures-lite v2.6.1 (*)
│   └── piper v0.2.4
│       ├── atomic-waker v1.1.2
│       ├── fastrand v2.3.0
│       └── futures-io v0.3.32
├── enumflags2 v0.7.12
│   ├── enumflags2_derive v0.7.12 (proc-macro)
│   │   ├── proc-macro2 v1.0.106 (*)
│   │   ├── quote v1.0.45 (*)
│   │   └── syn v2.0.117 (*)
│   └── serde v1.0.228
│       ├── serde_core v1.0.228
│       └── serde_derive v1.0.228 (proc-macro)
│           ├── proc-macro2 v1.0.106 (*)
│           ├── quote v1.0.45 (*)
│           └── syn v2.0.117 (*)
├── event-listener v5.4.1 (*)
├── futures-core v0.3.32
├── futures-lite v2.6.1 (*)
├── hex v0.4.3
├── libc v0.2.183
├── ordered-stream v0.2.0
│   ├── futures-core v0.3.32
│   └── pin-project-lite v0.2.16
├── rustix v1.1.4 (*)
├── serde v1.0.228 (*)
├── serde_repr v0.1.20 (proc-macro)
│   ├── proc-macro2 v1.0.106 (*)
│   ├── quote v1.0.45 (*)
│   └── syn v2.0.117 (*)
├── tracing v0.1.44
│   ├── pin-project-lite v0.2.16
│   ├── tracing-attributes v0.1.31 (proc-macro)
│   │   ├── proc-macro2 v1.0.106 (*)
│   │   ├── quote v1.0.45 (*)
│   │   └── syn v2.0.117 (*)
│   └── tracing-core v0.1.36
│       └── once_cell v1.21.3
├── uuid v1.22.0
│   └── serde_core v1.0.228
├── winnow v1.0.0
├── zbus_macros v5.14.0 (proc-macro)
│   ├── proc-macro-crate v3.5.0
│   │   └── toml_edit v0.25.3+spec-1.1.0
│   │       ├── indexmap v2.12.1
│   │       │   ├── equivalent v1.0.2
│   │       │   └── hashbrown v0.16.1
│   │       ├── toml_datetime v1.0.0+spec-1.1.0
│   │       ├── toml_parser v1.0.9+spec-1.1.0
│   │       │   └── winnow v0.7.15
│   │       └── winnow v0.7.15
│   ├── proc-macro2 v1.0.106 (*)
│   ├── quote v1.0.45 (*)
│   ├── syn v2.0.117 (*)
│   ├── zbus_names v4.3.1
│   │   ├── serde v1.0.228 (*)
│   │   ├── winnow v1.0.0
│   │   └── zvariant v5.10.0
│   │       ├── endi v1.1.1
│   │       ├── enumflags2 v0.7.12 (*)
│   │       ├── serde v1.0.228 (*)
│   │       ├── winnow v1.0.0
│   │       ├── zvariant_derive v5.10.0 (proc-macro)
│   │       │   ├── proc-macro-crate v3.5.0 (*)
│   │       │   ├── proc-macro2 v1.0.106 (*)
│   │       │   ├── quote v1.0.45 (*)
│   │       │   ├── syn v2.0.117 (*)
│   │       │   └── zvariant_utils v3.3.0
│   │       │       ├── proc-macro2 v1.0.106 (*)
│   │       │       ├── quote v1.0.45 (*)
│   │       │       ├── serde v1.0.228 (*)
│   │       │       ├── syn v2.0.117 (*)
│   │       │       └── winnow v1.0.0
│   │       └── zvariant_utils v3.3.0 (*)
│   ├── zvariant v5.10.0 (*)
│   └── zvariant_utils v3.3.0 (*)
├── zbus_names v4.3.1 (*)
└── zvariant v5.10.0 (*)

zbus supports multiple async runtimes. That's a reasonable thing to want, and the dependency count is what it costs. abus doesn't need the flexibility, so it skips it: Tokio only, written from scratch.

The same thinking applies to third-party crates generally. A few examples:

• Hex encoding shows up in exactly two places, so there's no hex crate. A dozen lines of code don't justify pulling in a library.
• D-Bus UUID is explicitly not standard UUID v4, so instead of reaching for the uuid crate, abus implements it directly. The approach is adapted from nanoid: 16 random bytes from getrandom, hex-encoded to 32 characters as the spec requires.

Roadmap

In progress

Core abus library: authentication, connection handling, message marshalling and unmarshalling, and the full client-side D-Bus protocol. A rough abusctl companion ships alongside to exercise the protocol and validate it against a real bus.

Planned

Public API, code generation from D-Bus XML introspection so you don't hand-write bindings, and a fully featured abusctl for inspecting services, calling methods, and monitoring signals.

Future

abusd: a session and system bus broker daemon. Anything that works with dbus-daemon or dbus-broker should work with abusd as a drop-in.

Experimental

Once the core is stable, abus will be a testbed for an alternative IPC protocol. The idea is full wire compatibility: existing software keeps working, new software can opt into something better. This is experimental and a long way off.

License

This project is licensed under the Apache-2.0 License. For more information, please see the LICENSE file.