pi-loop-guard

Prevents infinite tool call loops in pi by counting tool calls and turns, then aborting the agent when a configurable threshold is exceeded.

Why?

When the LLM encounters repeated errors (database connection failures, missing API keys, etc.), it can get stuck in an infinite loop of tool calls that all return the same error. This extension detects and stops that pattern.

Installation

Via pi package (recommended)

pi install git:unraid.local:3003/pi-dev/pi-loop-guard

Manual

Place in ~/.pi/agent/extensions/ or .pi/extensions/:

cp -r pi-loop-guard ~/.pi/agent/extensions/pi-loop-guard

Configuration

Add to .pi/settings.json or ~/.pi/agent/settings.json:

{
  "loopGuard": {
    "maxToolCalls": 50,
    "maxTurns": 20
  }
}

Setting	Default	Description
maxToolCalls	50	Maximum total tool calls before abort
maxTurns	20	Maximum turns (LLM responses) before abort

Behavior

• Counts tool calls across all turns in a session
• Counts total turns (LLM responses)
• When either threshold is exceeded, calls ctx.abort() to stop the agent
• Displays an error notification with details

Example

Loop guard: stopped after 51 tool calls (threshold: 50). Possible infinite loop detected.