🌀 pi-context-optimizer

Plan → Review → Execute → Walkthrough — a structured, gate-driven workflow loop for the pi coding agent.

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✨ What is it?

pi-context-optimizer brings a structured human-in-the-loop workflow to the pi coding agent. Instead of letting the agent code freely from the start, this extension enforces a disciplined five-phase cycle to optimize context, prevent runaway file writes, and align on goals before execution:

┌─────────────────────────────────────────────────────────────┐
│                      5-PHASE LOOP                          │
│                                                             │
│   INERT ──/plan──▶ RESEARCHING ──write_plan──▶ PLAN_DRAFTING │
│                                                   │         │
│                                                   ▼         │
│   EXECUTING ◀───/approve─────────────── REVIEW_PENDING      │
│       │                                                     │
│       └── all done ──write_walkthrough──▶ INERT              │
└─────────────────────────────────────────────────────────────┘

During RESEARCHING / PLAN_DRAFTING / REVIEW_PENDING, the agent is blocked from editing code — it can only read, explore, and reason. Once a plan is written and you approve it, the gates open and the agent executes step-by-step, reporting progress after each step.

Perfect for:

• 🎯 Complex, multi-step refactors where you want a plan before any code changes
• 🧪 Code reviews with an AI — see the plan, approve or reject, then watch it execute
• 📚 Knowledge capture — the walkthrough artifact persists what changed and why
• 🤝 Collaborative sessions — /grill mode to interview the agent before it drafts

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📋 Prerequisites

To use pi-context-optimizer, ensure you have the following:

1. Node.js: node >= 18
2. Pi Coding Agent: pi >= 0.78.0 installed globally or locally.
3. Sub-agent Infrastructure:
   • kmmuntasir/pi-nested-subagents:src (or configured sub-agent tools on the agent system) for executing nested agent sessions.
   • tsedr-runtime (T-SEDR) configured globally or locally to hook into agent sessions.
4. VS Code Extension (Optional): tufaan42.pi-context-optimizer for human-in-the-loop plan reviews and approval controls directly in the IDE.
5. Peer Dependencies:
   • @earendil-works/pi-coding-agent >= 0.78.0
   • @earendil-works/pi-tui >= 0.78.0
   • typebox >= 1.1.0

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🚀 Step-by-Step Integration Guide

Step 1: Install the Extension

Install pi-context-optimizer in your project or globally alongside pi:

npm install pi-context-optimizer

Step 2: Configure pi to Load the Extension

Add the extension name to your configuration. You can do this at the project level or globally.

Option A: Project-Level Configuration (Recommended)

Create a .pirc.json file in the root of your workspace:

{
  "extensions": [
    "pi-context-optimizer"
  ]
}

Option B: Global Configuration

Add the extension to ~/.pi/config.json:

{
  "extensions": [
    "pi-context-optimizer"
  ]
}

Step 3: Run the pi Agent

Launch pi in your workspace. You should see an initialization message confirming the optimizer is loaded:

[CONTEXT OPTIMIZER] pi-context-optimizer is loaded. Use /plan to start a structured plan→review→execute→walkthrough workflow, or just start coding normally.

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🧑‍💻 Using the Workflow

Interactive Slash Commands

The extension registers the following commands to control the workflow:

Command	Phase	Description
/plan	INERT → RESEARCHING	Enter read-only research mode to draft a plan.
/grill	RESEARCHING / PLAN_DRAFTING	Open an interactive grill/interview session to align details.
/done	PLAN_DRAFTING	Exit grill mode and indicate readiness to finalize the plan.
/approve	REVIEW_PENDING → EXECUTING	Approve the plan, opening write permissions.
/reject	REVIEW_PENDING → PLAN_DRAFTING	Reject the plan and provide feedback for a revision.

CLI Flag

You can also start a session auto-booted in planning mode:

pi --ag-plan "Refactor the database layer to use Drizzle ORM"

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📁 Artifact Structure

During the session, pi-context-optimizer creates structured artifacts under .pi/context-optimizer/<session-id>/:

• plan.md: The human-reviewable implementation plan.
• tasks.md: A live checklist representing step progress.
• walkthrough.md: A summary of changes and verification results.
• status.json: Machine-readable state representing phase/approval.
• knowledge/: Directory containing cross-session knowledge items.

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🔗 Host Integration (Bridge)

pi-context-optimizer is host-agnostic: any tool built on pi — the original pithings/pi-vscode extension, PiLot Studio, a JetBrains plugin, or a custom web UI — can integrate the plan→review→execute→walkthrough flow without HTTP, tokens, or in-process embedding.

The primary contract is the filesystem artifact protocol: the plan/tasks/ walkthrough/status files are always written to disk, and a stable active.json pointer lets a host discover the active session by watching one file. The approval gate is file-based — approve/reject by writing status.json, which the extension reconciles via fs.watch.

The original pi-vscode HTTP bridge (openFile / setPlanStatus) still works but is now a cosmetic, auto-detected enhancement, not a dependency. A host that provides nothing still gets a fully functional workflow.

👉 Full contract, schemas, and a minimal integration recipe: see BRIDGE.md.

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🧠 Context Optimization & Parallel Sub-agents

Context Window Optimization

To prevent context window bloat and keep sub-agents running fast and cost-effectively, pi-context-optimizer implements strict context isolation:

• Strict Context Isolation: Sub-agents are spawned with inherit_context: false so they do not inherit the massive main session chat history.
• Targeted Context Propagation: The dispatcher constructs a minimal, highly-focused prompt for each sub-agent containing only:
  • The high-level plan summary.
  • The specific step description to execute.
  • The precise outputs of its direct and transitive prerequisite steps (predecessors in the dependency DAG).

Parallel Sub-agent Spawning

When a plan is approved, the engine compiles the steps into a Directed Acyclic Graph (DAG) and executes independent branches concurrently:

• DAG Resolution: Steps that have all prerequisites completed are marked as ready.
• Concurrent Dispatching: Ready steps are dispatched in parallel using the Agent tool, adhering to a defined concurrency limit (concurrencyLimit).

Framework & Registry Integration

pi-context-optimizer is designed to run in environments utilizing:

• kmmuntasir/pi-nested-subagents: The core execution engine relies on the nested sub-agent spawning API (Agent tool) exposed by the kmmuntasir/pi-nested-subagents:src package to spawn child tasks.
• T-SEDR (tsedr-runtime): Fully integrates with tsedr-runtime. When a sub-agent session starts, T-SEDR's global before_agent_start hook executes within the sub-agent session to provide runtime validation and environment setup.

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🔧 API Reference

Programmatic Integration

If you are developing a custom extension wrapper for pi, you can import and register pi-context-optimizer programmatically:

import contextOptimizer from "pi-context-optimizer";
import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";

export default function myExtension(pi: ExtensionAPI): void {
  // Register the optimizer extension
  contextOptimizer(pi);
}

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🧪 Development & Testing

If you are contributing to this extension:

1. Clone the repository:

   git clone https://github.com/tufaan42/pi-context-optimizer.git
   cd pi-context-optimizer
   

2. Install dependencies:

   npm install
   

3. Run the development/build pipeline:

   npm run build      # Compile TypeScript (dist/)
   npm run typecheck  # Run type checking without emit
   npm test           # Execute unit and E2E tests
   

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📄 License

MIT © 2026 Tufaan