Sierra rebuilds Agent Studio around Ghostwriter, its agent-building agent

Sierra announced on November 2, 2026 that it has redesigned Agent Studio around Ghostwriter, its agent-building agent. The update brings investigation, journey editing and testing into a single conversation, according to the company.

What changed

Evidence, proposed changes and test results now stay together in the same thread, so teams can review them before anything goes live. Previously, users had to move between different parts of Agent Studio to edit journeys, run simulations and review performance.

Under the new workflow, a user can ask Ghostwriter why resolution rates changed, and the investigation starts from that question inside the conversation. The feed summary of the announcement is cut off at this point, so further details of the example are not available.

Details not provided

The announcement summary does not state pricing, availability tiers or a rollout schedule. No benchmark figures, context window size or model parameters are given, and none apply here: this is a product workflow update, not a new model release.

What this means

The change moves Agent Studio from separate tools for editing, simulation and performance review to a conversation-led workflow. Keeping evidence, proposed changes and test results in one place means a reviewer can see why a change was suggested and how it tested before it goes live. For teams that maintain customer-facing agents, that reduces the switching between parts of the product that the previous workflow required.