assertNever / assert_never
Ends a switch over a union, so a variant nobody handles is a type error.
Python uses typing.assert_never, which threads does not re-export.
Import from @threads/core (TypeScript) or threads (Python).
function assertNever(value: never): neverParameters
valueneverrequiredThe value no case matched; the type checker proves none can.
Returns
never
runEvals / run_evals
Runs every saved case under cases through the checks, cheapest first: replay (the recorded requests re-render byte for byte with the code running now), rerun (the recorded turn reruns offline to the same events, with no model call and every effect stubbed), drift (with agents: the case's recorded config against each agent as it is pinned now, by a dry pin that runs no setup, reads no secret and connects to no MCP server) and, only with live, a judged run of the current agent.
otel
An Exporter that sends each span of every thread in the store once, when it closes, to an OpenTelemetry collector over OTLP/HTTP JSON.