The rest of this site shows the smallest fragment that makes a point. This section shows whole programs: imports at the top, assertions at the bottom, nothing hidden. Copy one into a file and it runs.
Three of them, in the order they are worth reading:
1. Produce and consume
The smallest complete loop. Create a queue, push, consume with a group, acknowledge, and check every message arrived exactly once.
2. Ordering and deduplication
One partition per entity, so each entity keeps its own order. Then the same push twice, and the broker refusing the second.
3. Transactional pipeline
Acknowledge one stage and push the next in a single database transaction, and watch a failed message come back rather than vanish.
Each is written three times, once per language, so you can read the one you use and compare it against the one you do not.
What “run before it ships” means here
The nine programs live in examples/full/ in the repository. They are not transcribed into these
pages: the build extracts each file between its first and last line and includes it verbatim, so
what you read is the file that ran.
Every program asserts its own outcome and exits non-zero when an assertion fails. That is the part that makes this claim worth anything: a program that only printed “ok” would prove nothing.
To run all nine yourself against a broker of your own:
QUEEN_URL=http://localhost:6632 examples/full/run.shThe script checks the broker answers, installs the JavaScript dependencies on first use, and
prints a pass or fail line per program. It needs Node 22, Python 3.9 with httpx, and Go 1.24,
and it takes the clients from this repository rather than from the registries, so it exercises
the code in the tree rather than the last release.