Users who react.
Customers change their minds. Coworkers ask follow-up questions. Simulated users respond to your agent and introduce new information as the task unfolds.
Krux simulates your users, stateful tools, and business rules.
Develop capable agents, catch failures before deployment,
and improve with every iteration.
A user changes their mind. A tool times out after moving money. A policy blocks the next step.
The hard part is finishing the job correctly - even when the conditions change.
Test what happens nextConnect the agent you’re already building.
Krux simulates the world around it, from the first request to the final outcome.
From customer-facing software to your internal APIs. Model the state, responses, and failures your agent needs to navigate across an entire workflow.
A refund succeeds, but the response times out. Model the payment state your agent needs to check before trying again.
refund: issued · response: timeoutExample systems to model, including the services and internal tools in your stack.
One refund workflow. Three situations a happy-path test can miss. Explore what your agent needs to get right.
Please refund the charge on order #1042.
The payment went through. The API response didn’t.
Payment succeeds, but the tool times out.payments.refundRetries the refund without checking whether it already succeeded.
refund_count: 2Check the transaction state before retrying a timed-out payment.
payments.refund_count === 1Iterate on prompts, tools, and agent logic against repeatable scenarios. Check each change against past failures - and turn real-world surprises into the next scenario.
Let’s simulate the workflow you want to automate.