Matchers

expect(subject) creates an Expectation whose methods raise AssertionError when captured evidence does not satisfy the predicate. check(subject) records failures through a CheckGroup, allowing several related checks to be reported together when the plugin has a recording binding.

Use matchers for execution and trace evidence: tool names, qualified tool choices, arguments, results, status, counts, messages, and terminal outcomes. Pass a TurnResult when a check should apply to one turn rather than the whole session.

expect(result).to_have_tool_call("shipping_quote", arguments={"weight_kg": 2, "zone": "local"},
    status="success",
)

Unavailable evidence fails a predicate that requires it; it is not treated as an empty value. Matcher failures are ordinary assertion failures even when the plugin also records them as evaluation evidence.