AI · Oct 2, 2026 · 9 min read
I Put a 20B Model on My Laptop Under a Bank Mandate. It Took One of 45 Nudges and Left Six Jobs Undone.
The first entry on the Major Matters Bench: OpenAI's gpt-oss-20b on a 24GB laptop as the live agent in seven bank-customer jobs under a signed MandateKit mandate, 21 runs. It took one of 45 unrequested options and the ask rule caught it. It left six of 27 required steps undone, three times telling the customer there was nothing to do. The runtime's parser rejected its output nine times. Measurements and evidence files, no scores.