Ghostwriter is Sierra's "Agents as a Service" tool, announced on March 25, 2026 by co-founders Bret Taylor and Clay Bavor. It enables the creation and deployment of production-ready AI agents purely from natural-language descriptions — without writing code, manually configuring integrations, or designing workflows.
Users provide source materials — SOPs, support call transcripts, whiteboard photos, process documentation, audio recordings — or describe their goal in plain English. Ghostwriter ingests all of it, identifies key behaviors and edge cases, and generates a production-ready agent across voice, chat, email, and 30+ languages with sophisticated guardrails built in.
Ghostwriter includes an Explorer module — a customer-conversation analysis tool analogous to ChatGPT Deep Research, but applied to a company's own interaction data. Explorer identifies trends and improvement opportunities; Ghostwriter then validates proposed changes in a sandboxed environment and prepares them for deployment. This creates a continuous loop of analysis, improvement, testing, and shipping — with no manual operator intervention.
Ghostwriter has been generally available since March 2026 as part of the Sierra Agent OS platform, offered exclusively to enterprise customers.