pyomq 0.8.1

Python binding for omq.rs (Rust libzmq port). Drop-in pyzmq replacement on the common path.

pyomq

Python binding for omq.rs, a Rust libzmq port. Drop-in pyzmq replacement on the common path.

Install

uv pip install pyomq
uv pip install 'pyomq[test]'   # adds pytest, pyzmq for the interop suite

The published wheel includes optional features: plain, curve, lz4, zstd. Use pyomq.has("curve") at runtime to check availability.

Usage

import pyomq as zmq  # drop-in for `import zmq` from pyzmq

ctx = zmq.Context()
push = ctx.socket(zmq.PUSH)
push.connect("tcp://127.0.0.1:5555")
push.send(b"hello")
push.close()
ctx.term()

For asynchronous code:

import pyomq
import pyomq.asyncio as zmq_async

ctx = zmq_async.Context()
sock = ctx.socket(pyomq.PUSH)
await sock.connect("tcp://127.0.0.1:5555")
await sock.send(b"hello")
await sock.close()

Status

Sync and asyncio APIs both ship in this release. All 19 ZMTP socket types are wired:

• Standard (RFC 28 + 47): PAIR, PUB, SUB, REQ, REP, DEALER, ROUTER, PULL, PUSH, XPUB, XSUB.
• Draft: SERVER, CLIENT (RFC 41), RADIO, DISH (RFC 48), GATHER, SCATTER (RFC 49), PEER, CHANNEL (RFC 51).

Transports: tcp://, ipc://, inproc://, and udp:// (RADIO/DISH only). Optional features built into the wheel: plain, curve, lz4, zstd.

DISH groups: use socket.join(b"group") / socket.leave(b"group") to manage subscriptions; messages are sent as multipart [group, body].

Backend

pyomq is built on omq-compio (single-threaded io_uring on Linux). The runtime runs on a dedicated background thread; every Python call releases the GIL across the runtime trip. This is the only backend pyomq supports — the omq-tokio backend exists in the upstream Rust workspace for callers that need a multi-thread tokio integration, but pyomq's per-call overhead is shaped around compio's single-thread invariant.

Performance

See BENCHMARKS.md for full tables.

Loopback PUSH/PULL throughput vs pyzmq, on a Linux 6.12 (Debian 13) VM on an Intel Mac Mini 2018 (i7-8700B, 3.2 GHz), Rust 1.95.0, default features:

Size	inproc pyomq	inproc pyzmq	ratio	tcp pyomq	tcp pyzmq	ratio
8 B	1.68 M/s	602 k/s	2.79×	1.58 M/s	569 k/s	2.79×
16 B	1.47 M/s	614 k/s	2.39×	1.60 M/s	517 k/s	3.09×
32 B	1.67 M/s	618 k/s	2.70×	1.60 M/s	546 k/s	2.92×
64 B	1.66 M/s	566 k/s	2.94×	1.57 M/s	538 k/s	2.92×
128 B	1.67 M/s	526 k/s	3.18×	1.57 M/s	497 k/s	3.15×
256 B	1.67 M/s	522 k/s	3.20×	1.55 M/s	498 k/s	3.10×
512 B	1.67 M/s	503 k/s	3.31×	1.41 M/s	479 k/s	2.94×
1 KiB	1.55 M/s	465 k/s	3.34×	1.34 M/s	464 k/s	2.90×
2 KiB	1.52 M/s	460 k/s	3.31×	998 k/s	364 k/s	2.74×
4 KiB	1.49 M/s	389 k/s	3.81×	582 k/s	203 k/s	2.87×
8 KiB	1.32 M/s	361 k/s	3.67×	336 k/s	104 k/s	3.24×
16 KiB	1.02 M/s	256 k/s	3.97×	176 k/s	56 k/s	3.13×
32 KiB	748 k/s	188 k/s	3.98×	111 k/s	46 k/s	2.40×
64 KiB	541 k/s	117 k/s	4.64×	55 k/s	37 k/s	1.46×
128 KiB	304 k/s	71 k/s	4.28×	26 k/s	24 k/s	1.06×
256 KiB	131 k/s	37 k/s	3.50×	15 k/s	15 k/s	1.00×

REQ/REP latency (TCP loopback)

Serial ping-pong: 1000 warmup + 10000 measured iterations per cell. Lower is better; ratio = pyzmq / pyomq.

Size	pyomq p50	pyzmq p50	ratio	pyomq p99	pyzmq p99	ratio
8 B	63.1 µs	67.9 µs	1.08×	96.9 µs	103 µs	1.06×
16 B	63.3 µs	69.5 µs	1.10×	82.3 µs	91.6 µs	1.11×
32 B	63.7 µs	69.9 µs	1.10×	79.2 µs	90.4 µs	1.14×
64 B	64.0 µs	70.2 µs	1.10×	84.1 µs	96.9 µs	1.15×
128 B	62.8 µs	69.4 µs	1.10×	80.3 µs	92.5 µs	1.15×
256 B	62.2 µs	70.6 µs	1.14×	87.3 µs	99.0 µs	1.13×
512 B	64.0 µs	69.0 µs	1.08×	90.1 µs	103 µs	1.15×
1 KiB	64.1 µs	70.8 µs	1.10×	83.4 µs	96.8 µs	1.16×
2 KiB	66.6 µs	71.2 µs	1.07×	87.7 µs	99.7 µs	1.14×
4 KiB	66.0 µs	76.9 µs	1.16×	93.9 µs	109 µs	1.16×
8 KiB	73.6 µs	89.5 µs	1.22×	102 µs	116 µs	1.14×
16 KiB	75.6 µs	92.6 µs	1.23×	93.5 µs	115 µs	1.23×
32 KiB	81.2 µs	100 µs	1.23×	128 µs	143 µs	1.11×
64 KiB	109 µs	115 µs	1.06×	146 µs	150 µs	1.02×
128 KiB	149 µs	146 µs	0.98×	211 µs	191 µs	0.90×

zmq.proxy() forwarding (128 B, TCP)

	pyomq	pyzmq	ratio
PUSH/PULL msg/s	1.34 M/s	540 k/s	2.48×
REQ/REP rt/s	11,222/s	6,599/s	1.70×

pyomq's proxy() forwards directly between sockets on the compio thread — no rings, no Python per-message overhead. pyzmq's zmq.proxy() calls libzmq's C-level zmq_proxy. PUSH/PULL forwarding is throughput-bound and pyomq is ~2.5× faster. REQ/REP proxy is latency-bound (4 TCP hops per round-trip); pyomq is ~1.7× faster thanks to direct socket forwarding.

Run scripts/update_perf.py (after maturin develop --release) to re-measure and update the tables above.

Compression transports

OMQ.rs adds two transparent compression transports on top of TCP: lz4+tcp:// (fast, low-latency) and zstd+tcp:// (higher ratio, better for large or structured payloads). Swap the scheme in your endpoint string and everything else stays the same:

push = ctx.socket(zmq.PUSH)
push.bind("lz4+tcp://127.0.0.1:5555")   # or zstd+tcp://

pull = ctx.socket(zmq.PULL)
pull.connect("lz4+tcp://127.0.0.1:5555")

Both peers must use a matching compression endpoint. Payloads below ~512 B are sent as-is (the codec detects that compression would expand them). For realistic JSON payloads at 2 KiB, lz4 yields ~3.8× and zstd ~4.5× on a bandwidth-limited link.

zstd+tcp:// also auto-trains a dictionary: it samples the first 1000 outbound messages (or 100 KiB of plaintext, whichever comes first), builds an 8 KiB dict, and ships it to the peer once. After that the compression threshold drops from 512 B to 64 B, so small structured messages start compressing too. lz4+tcp:// does not auto-train (LZ4 has no standard dict trainer).

Virtual throughput on bandwidth-limited links (JSON payloads, compio backend):

See BENCHMARKS_COMPRESSION.md for full tables including dict-trained ratios.

CURVE authentication

CURVE encrypts traffic and authenticates the server to the client. To also authenticate clients to the server, call set_curve_auth() before bind()/connect():

server_pub, server_sec = zmq.curve_keypair()
client_pub, client_sec = zmq.curve_keypair()

pull = ctx.socket(zmq.PULL)
pull.curve_server = 1
pull.curve_publickey = server_pub
pull.curve_secretkey = server_sec

# Option 1: allow specific client keys (checked in Rust, no GIL overhead)
pull.set_curve_auth([client_pub])

# Option 2: custom callback receiving a PeerInfo with a .public_key (Z85 bytes)
pull.set_curve_auth(lambda peer: peer.public_key in allowed_keys)

# Option 3: accept any valid CURVE client (the default)
pull.set_curve_auth(None)

No ZAP, no filesystem key management. The callback runs during the CURVE handshake; returning a falsy value rejects the client.

Develop

cd bindings/pyomq
uv venv && source .venv/bin/activate
uv pip install maturin pytest pyzmq
maturin develop --release
pytest -v