Bang Don't Ghost

Most of this extension was written with the pi agent CLI.

Automatically starts an agent follow-up after a user-entered single-! shell command finishes, instead of leaving the recorded result waiting for another prompt.

Back to the extension workspace

Runtime requirement

Bang Don't Ghost requires Pi to emit a post-execution user_bash_result extension event after recording the matching bashExecution message. Stock Pi does not currently provide this event in its published extension API. The local patcher supports only the installed Pi 0.87.0 bundled runtime and fails closed for every other version or layout.

The expected runtime payload is:

interface UserBashResultEvent {
  type: "user_bash_result";
  command: string;
  excludeFromContext: boolean;
  result: {
    output: string;
    exitCode: number | undefined;
    cancelled: boolean;
    truncated: boolean;
    fullOutputPath?: string;
  };
}

Without that runtime patch, the event never fires and the extension does nothing. There is no polling fallback.

Patch command

This source checkout includes an idempotent patcher at scripts/patch-pi-user-bash-result.mjs. On this development machine, a command shim is installed at ~/.pi/agent/bin/pi-patch-user-bash-result and invokes the versioned repository script.

Run it after pi update, after changing the active FNM Node installation, or whenever the patch may have been replaced:

pi-patch-user-bash-result

The command:

• requires Pi 0.87.0 and its bundled dist/bundle/cli.js layout
• resolves the active pi executable from PATH, including the current pnpm command shim
• locates the single bundled runtime chunk containing AgentSession
• accepts the exact current patch without rewriting the file
• patches both direct recording and deferred-result flushing after context refresh
• writes through a same-directory temporary file and runs node --check before an atomic rename
• leaves Pi unchanged, prints diagnostics, shows a macOS notification, and exits nonzero when the version, layout, or exact anchors differ

Run this command manually. Pi startup does not run it. Rerun it after reinstalling Pi 0.87.0. A newer Pi release requires a patcher update, and the patcher will not apply an older patch. The patcher and command shim are development tools and are not included in the published npm package.

For an explicit Pi 0.87.0 bundled runtime test target, the repository script also accepts --target <runtime.js>.

Usage

Run a normal single-bang command:

!npm test

Pi records the command and output in model context, then emits user_bash_result. Bang Don't Ghost responds by submitting an empty, non-displayed custom message that starts the next agent turn. It does not copy the command or output into a second message.

Behavior:

• successful and nonzero command results start a follow-up
• user-cancelled commands do not start a follow-up
• !!command results do not start a follow-up
• Pi's follow-up queue delivers commands completed while the agent is busy
• LLM-initiated bash tool calls are unaffected
• the extension uses no timer, session-entry scan, command tracker, or command-text correlation

The extension has no slash command or configuration; installing it enables the behavior. Every eligible command starts a model-provider request, which may incur usage charges.

Installation

Install the standalone package:

pi install npm:@stagefright5/pi-bang-dont-ghost

For source development and tests, see the source README and workspace development guide.

Event flow

user enters !command
        │
        ▼
Pi executes through its selected local/custom backend
        │
        ▼
Pi records bashExecution with command and output
        │
        ▼
Pi emits user_bash_result
        │
        ▼
Bang Don't Ghost skips !! and cancelled results
        │
        ▼
empty hidden message, deliverAs: followUp, triggerTurn: true
        │
        ▼
next agent turn

The local event type and one isolated pi.on cast can be removed when Pi publishes user_bash_result in its TypeScript declarations.