Building Spectre: Internal Collaborative Cloud Agent Platform | Harvey

This post details the architecture and design decisions behind Spectre, Harvey's internal collaborative cloud agent platform. It introduces core technical primitives: durable runs (the primary object of collaboration) and ephemeral workers (short-lived execution units), sandboxes as execution boundaries for security and correctness, a harness component that orchestrates models and tools into a durable and observable system, and the integration of collaboration surfaces (Slack, web run page) as part of the runtime. It also highlights the importance of scheduled runs using the same runtime as interactive work and emphasizes security through explicit boundaries.