nats-extra

Core NATS extensions. The first utility is request-many, a streaming request/reply and scatter-gather pattern matching nats-extra in orbit.rs.

Install

pip install nats-extra

Usage

import nats.extra
from nats.client import connect

nc = await connect("nats://localhost:4222")

responses = await nats.extra.request_many(
    nc,
    "services.ping",
    b"ping",
    stall_wait=0.25,  # stop after 250 ms without another response
)
async for response in responses:
    print(response.data)

print(responses.termination_reason)

Request streams can terminate on max_messages, max_wait, stall_wait, a sentinel predicate, a no-responders status, or subscription closure. The reason is available as responses.termination_reason.

The orbit.rs-style builder is also available:

responses = await (
    nats.extra.RequestMany(nc)
    .max_messages(10)
    .stall_wait(0.25)
    .sentinel(lambda message: message.data == b"done")
    .send("services.work", b"start")
)

Natural termination unsubscribes automatically. When abandoning a response stream early, call await responses.aclose() or use it as an async context manager.

License

Apache 2.0