pyomq 0.11.0

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.

2-process loopback throughput and latency vs pyzmq, measured on Linux 6.12 (Debian 13), Intel i7-8700B 3.2 GHz, Rust 1.95.0.

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

	pyomq	pyzmq	ratio
PUSH/PULL msg/s	986 k/s	522 k/s	1.89×
REQ/REP rt/s	11,406/s	6,221/s	1.83×

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, regenerate the chart, and update the proxy table.

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, dict 2 KiB):

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.

BLAKE3ZMQ authentication

BLAKE3ZMQ is an omq-native encryption mechanism using BLAKE3 key derivation and ChaCha20 encryption. Keys are raw 32-byte X25519 keypairs (not Z85-encoded like CURVE). Setup mirrors CURVE:

server_pub, server_sec = zmq.blake3zmq_keypair()
client_pub, client_sec = zmq.blake3zmq_keypair()

pull = ctx.socket(zmq.PULL)
pull.blake3zmq_server = 1
pull.blake3zmq_publickey = server_pub
pull.blake3zmq_secretkey = server_sec

push = ctx.socket(zmq.PUSH)
push.blake3zmq_serverkey = server_pub
push.blake3zmq_publickey = client_pub
push.blake3zmq_secretkey = client_sec

# Client authentication (same three options as CURVE)
pull.set_blake3zmq_auth([client_pub])                         # allow list
pull.set_blake3zmq_auth(lambda peer: peer.public_key in ok)   # callback
pull.set_blake3zmq_auth(None)                                 # accept all

The callback receives a PeerInfo with a .public_key attribute (raw 32-byte bytes). Requires the blake3zmq feature (pyomq.has("blake3zmq")).

[!WARNING] BLAKE3ZMQ has not been independently security audited. It's an omq-native construction (Noise XX + BLAKE3 + X25519 + ChaCha20-BLAKE3) and should not be relied on for anything that matters until it has had third-party review. Use CURVE (RFC 26) for production / regulated workloads.

Develop

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