Cognitive / Multi-Agent AI System

Arc - AI Multi-Agent Planning System (Product Management AI)

A LangGraph multi-agent planning system that turns a goal into research, analysis, critique, and an executable plan. WebSocket streaming, checkpoints, and persisted state make long-running sessions visible and resumable.

Role
Solo builder · architecture, implementation, and operations
Period
2025 - Present
Organization
Personal Project
01 / Overview

A LangGraph multi-agent planning system that turns a goal into research, analysis, critique, and an executable plan. WebSocket streaming, checkpoints, and persisted state make long-running sessions visible and resumable.

DECISION / AThe problem

What made this system difficult?

Needed realtime visibility into multi-step agent runs, plus reliability features like checkpoint/resume and consistent persistence across reconnects.

DECISION / BThe response

How did the design respond?

Implemented StateGraph workflows and a FastAPI WebSocket endpoint that validates project ownership and streams workflow events/state sync. Added token/cost tracking backed by a pricing table and a checkpoint-driven resume flow for long-running executions.

02 / System architecture

How responsibility moves through the system.

01

Coordinator Agent

Workflow Orchestration

Responsibilities

  • — Workflow orchestration
  • — Task routing & coordination
02

Research Agents

Data Collection

Responsibilities

  • — Web research & synthesis
  • — Structured evidence gathering
03

Planner & Critic

Content Generation & QA

Responsibilities

  • — Structured plan generation
  • — Review/critique loop
03 / Technology
01Python02FastAPI03LangGraph04WebSocket05PostgreSQL
04 / Technical record

Overview

  • Solo-built LangGraph-based multi-agent planning system (Arc/PMAI).

Purpose & User Flow

Purpose

  • Automate planning: take a goal and produce structured deliverables via agent division of labor + critique loops.

User Flow

  • Input goal/context → run workflow (agent routing) → stream step-level progress and artifacts (WebSocket) → resume from checkpoints → export deliverables.

Key Components

  • StateGraph workflows with conditional routing between agent roles (backend/agents/graph.py)
  • FastAPI WebSocket streaming endpoint with state sync/resume (backend/api/websocket.py)
  • Token/cost tracking with pricing table + provider balances (backend/agents/token_tracker.py)
  • Checkpoint-based resume flow (resume_workflow)
05 / Project evidence
Arc - AI Multi-Agent Planning System (Product Management AI) project evidence
PROJECT VISUAL / CONCEPT IMAGE