AI Founder Weekly

Half of all T3 Code prompts now go to Opus 5.5

Theo says Opus 5.5 is the first model to take more than half of T3 Code's prompt traffic. Same week he shipped an overhaul that he warns will feel genuinely unstable.

Real money

Theo says Opus 5.5 now takes half of all T3 Code prompts

Theo says Opus 5.5 is the first model to break the 50% traffic threshold in T3 Code, with literally half of all prompts going to it. He gave no breakdown of what the remaining half splits into, or how the share moved over time.

Theo - t3.gg
@theo
X
Opus 5.5 is the first model we've seen break the 50% traffic threshold in T3 Code.
Oct 3, 2026 · View on X

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Stolen playbooks

Isenberg's manufacturing playbook: have a model write CAD as code

Greg Isenberg published a 13-step workflow for designing physical products with AI, from measuring with digital calipers to sending files to SendCutSend, Xometry or JLCPCB. The two steps that save money: prototype in plastic on a $300 to $600 printer first, then pay a mechanical engineer on Upwork for one hour to review the files before your first real order.

GREG ISENBERG
@gregisenberg
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Pay an engineer for 1 hour. Before your first real order, have a mechanical engineer on Upwork etc review the files. It's the cheapest insurance you'll ever buy.
Oct 3, 2026 · View on X

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What changed under us

T3 Code ships an overhaul Theo warns will break your nightly

Theo merged a release that adds Pi support, thread forking, mid-thread provider and model switching, and a `delegate_task` call that lets an agent start child agents on any provider. He cut one more stable build before merging and told daily drivers there is no shame in going back to it. He expects days of cleanup.

Theo - t3.gg
@theo
X
This release is gonna feel more "nightly" for sure.
Oct 2, 2026 · View on X

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