Source: external black-box user audit of PyPI aixplain 0.2.48 (finding #42). Verified offline against development @ e9f7061; the aixplain/ package there is byte-identical to main/0.2.48, so this is present on all branches.

Problem

Using the documented type in the documented per-run field fails:

ag.run("...", tasks=[aix.Agent.Task(name="t", description="d", expected_output="o")])
# TypeError: Object of type Task is not JSON serializable

tasks=[t.to_dict()] works, and construct-time Agent(tasks=[t]) works. Only the per-run path is broken.

Evidence

aixplain/v2/agent.py:2363-2366: the catch-all kwargs forwarder puts raw kwargs into the payload; Task objects reach json.dumps. The construct path serialises them via to_dict().

Suggested fix

payload["tasks"] = [t.to_dict() if isinstance(t, Task) else t for t in tasks] in build_run_payload, plus a unit test.