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Waitlist open

Write a better harness by practicing.

AI engineering moved to the systems around the model. Same model for everyone. A real environment. A hidden eval. Improve the loop until the number goes up.

Leave your email. We will send a seat when the playground is up.

How it works

Read the trace. Change the loop.

  1. 01

    Start from a weak loop

    The starter is already in the editor, with traces that fail. You do not burn a run just to watch it lose. Read those, then change the loop.

  2. 02

    Read a failing trace

    System prompt, every tool call, every result, the grader verdict. This is how you debug a harness.

  3. 03

    Edit and submit

    Thirty hidden tasks. Same model. Pass is 85 percent. A careful loop lands higher, with tokens still in budget.

Get a seat when it opens.

One email. We send the link when the playground is up.

FAQ

Questions

What is a harness?

The software around the model: the loop, the tools, the context, retries, when to stop. Not the model.

Why pin the model?

If everyone picks a different model, you cannot tell who built the better loop. Same model, same environment, same hidden eval. The only variable is the harness.

What is a trace?

The full transcript of one task: system prompt, every message, every tool call and result, the final answer, the grader verdict. You debug from this, not from the score.

When do I get in?

When the eval environment is hosted. We will email you a seat.

Is it free?

Yes for the waitlist and the first problems. A cheap pinned model. Run is three tasks. Submit is capped so nobody burns the bill.