@gotgenes/pi-nocd

Pi extension that adds an instruction to the system prompt forbidding the agent from cd-prefixing the current working directory.

Requires Pi 1.0.0 or later.

Why

Pi already tells the agent the resolved CWD: its system prompt carries a <cwd> section naming the path, and that section survives downstream shaping (for example pi-anthropic-auth, which only rewrites Pi's own tools, rules, and docs sections).

What Pi ships nowhere — default or shaped — is any instruction against cd-prefixing the CWD. The <cwd> section is a bare statement of fact, not a rule, so the habit of prefixing commands with cd $(pwd) && survives.

This extension hooks before_agent_start and adds a prompt section that supplies the missing prohibition — forbidding both the literal cd <path> && form and the generic cd $(pwd) && form. It repeats the literal resolved path (from ctx.cwd) only to make the forbidden cd <path> && example concrete, not because the path is otherwise unavailable to the agent.

Because the section names a literal path, each session writes its own. A subagent session runs its own copy of this extension, which writes a section naming the child's directory, so a child given an isolated workspace (for example a git worktree from @gotgenes/pi-subagents-worktrees) is told where its own shell commands execute. @gotgenes/pi-subagents drops everything from the parent's <cwd> section onward when it builds a child's prompt, so the parent's section is not carried along.

Install

pi install npm:@gotgenes/pi-nocd

Or add it to your Pi settings (~/.pi/agent/settings.json):

{
  "packages": ["npm:@gotgenes/pi-nocd"]
}

What it injects

For a session whose working directory resolves to /Users/you/project, Pi renders the following section right after its own <cwd> section (the instruction is one line in the prompt, split here at its sentences):

<working_directory>
Shell commands already execute in `/Users/you/project`.
Never prefix a command with `cd` into the current working directory — neither `cd /Users/you/project &&` nor `cd $(pwd) &&`.
Just run the command directly.
</working_directory>

The extension writes the section through systemPromptOptions.sections and never returns a replacement system prompt. A returned prompt would become Pi's forced prompt, which drops every section a later handler adds, such as the <mcp_servers> section Pi's built-in MCP support writes.

The converse also holds: when another extension returns a systemPrompt from before_agent_start before this one runs, Pi ignores every later section edit, and this section is dropped with them.

How it works

Scope and non-goals

Purpose. Pi tells the agent its working directory but never forbids cd-prefixing it. This extension supplies the missing prohibition — and nothing else.

In scope. The wording of the section, and naming the right directory when a child session runs in an isolated workspace.

Non-goals.

• Enforcing the rule. This extension instructs; it does not gate a command at execution time.
• Editing prompt text it did not write. The extension reads no prompt text, so another source's working-directory guidance is neither rewritten nor deduplicated.
• Telling the agent what its working directory is. Pi's own <cwd> section already does that; the literal path appears here only to make the forbidden example concrete.
• Registering tools or commands. The entire surface is one before_agent_start hook, with no configuration.

License

MIT