OpenClaw Architecture

Deep dive into the open-source AI agent framework — Gateway, Agent Runtime, sessions, memory & more

Overview

OpenClaw is an operating system for AI agents. It turns large language models into persistent, tool-using assistants with real-world integrations, session management, memory, and multi-channel support.

It follows a clean hub-and-spoke architecture with two core pillars:

🛡️ Gateway

Communication & control layer. Receives inputs, routes to agents, resolves sessions, and orchestrates flows.

⚡ Agent Runtime (Pi)

Execution layer where the model runs, tools execute, and tasks complete step-by-step.

How a Message Flows Through OpenClaw

  1. Channel Plugin — Normalizes messages from Slack, WhatsApp, Discord, iMessage, etc.
  2. Gateway Routing & Agent Selection — Applies routing rules, isolates agents (workspace, state, sessions).
  3. Session Resolution — Loads or creates sessions using session store (metadata) + transcripts (append-only log).
  4. System Prompt Construction — Combines tools, history, skills, memory (Markdown files), workspace files, time, and user message.
  5. Agent Runtime Loop — Pi executes ReAct-style loop: reason → tool call → observe → repeat.
  6. Response & Persistence — Gateway saves updated state and delivers formatted reply via channel.

Triggers & Autonomy

OpenClaw feels alive because it supports multiple event types:

Messages

Direct user input from any channel

Heartbeat

Periodic checks (default: every 30 min)

Cron Jobs

Scheduled tasks

Webhooks

External events (e.g. Stripe payments)

Hooks

Internal state-change triggers

Memory System

Simple yet powerful file-based memory:

  • memory.md — Long-term knowledge
  • memory/ directory — Timestamped daily notes & running context
  • Workspace files: IDENTITY.md, USER.md, SOUL.md, etc.

Key Takeaways

  • Isolated agent sessions prevent context collisions
  • Gateway ensures one active run per session (queuing)
  • Everything is local-first and persisted to disk
  • Extensible via plugins, skills, and custom tools

Reference

This page is based on the excellent detailed breakdown by @GargEtisha on X (May 2026).View original thread