div result

div result run-7
div result run-7 metrics.accuracy
div result run-7 | jq '.metrics'

Every run is given DIVERGENT_RESULT_PATH. A JSON object written there before the run exits is its result: the control plane keeps it with the run, judges the run’s checks against it, and div result prints it.

import json, os

with open(os.environ["DIVERGENT_RESULT_PATH"], "w") as f:
    json.dump({"metrics": {"accuracy": 0.91, "loss": 0.42}}, f)

The file is read once the process has exited, so it can be written at any point and rewritten as often as you like; the last version is the one kept.

A path picks one value

Given a path, div result prints the value there instead of the whole object: a string as it is, anything else as JSON. It reads the path the same way a check does, a key at a time between the dots.

acc=$(div result run-7 metrics.accuracy)   # 0.91

When there is nothing to print

div result exits 1, and says why on stderr, rather than printing an empty line a script would read as a value:

When	What it says
the run has not finished	run-7 is still running; its result arrives when it finishes
it wrote nothing	run-7 has no result: it wrote nothing to DIVERGENT_RESULT_PATH
it wrote something we could not keep	run-7 has no result: the result is not JSON
the path is not in it	run-7 has nothing at metrics.f1

A result has to be one JSON object of at most 64 KiB. One that is longer is refused whole, never cut short: half an object could pass a check the whole one would fail. Any value of one of the org’s secrets is masked in it, as it is in the log.