.windsurfrules

.windsurfrules is a project-level configuration file read by the Windsurf AI code editor to steer its Cascade assistant. Placed at the root of a repository, it carries the coding conventions, architectural constraints, and standing instructions a team wants the agent to honor every time it reads, writes, or refactors code — turning tacit team knowledge into rules the model actually follows.

• Repository-scoped context - The file travels with the codebase, so every contributor’s agent shares the same ground rules.
• Natural-language rules - Conventions are written as plain-language directives rather than lint config, so intent survives the round trip to the model.
• Persistent guidance - Rules apply across sessions and prompts without a developer restating them each time.
• One of a family of agent rule files - It sits alongside .cursorrules, CLAUDE.md, and AGENTS.md as an editor-specific way to encode the same idea.

In API work, a .windsurfrules file is where a team pins the standards an AI assistant should not drift from — which OpenAPI style to follow, how to structure handlers, which auth pattern to reuse, what naming to enforce. As agentic coding tools take on more of the day-to-day generation, these rule files become a governance surface in their own right: the place where an organization’s API design guidance and conventions get injected into the model’s working context, keeping machine-written code aligned with the same rules a human reviewer would apply.