Architectural Layers
Five orthogonal concerns that compose into a complete agent
L1 Tools & Execution
What the agent CAN do. The foundation: tools give the model capabilities to interact with the world.
L2 Planning & Coordination
How work is organized. From simple todo lists to dependency-aware task boards shared across agents.
TodoWrite
Plan Before You Act
An agent without a plan drifts; list the steps first, then execute
Subagents
Clean Context Per Subtask
Subagents use independent messages[], keeping the main conversation clean
Skills
Load on Demand
Inject knowledge via tool_result when needed, not upfront in the system prompt
Tasks
Task Graph + Dependencies
A file-based task graph with ordering, parallelism, and dependencies -- the coordination backbone for multi-agent work
L3 Memory Management
Keeping context within limits. Compression strategies that let agents work infinitely without losing coherence.
L4 Concurrency
Non-blocking execution. Background threads and notification buses for parallel work.
L5 Collaboration
Multi-agent coordination. Teams, messaging, and autonomous teammates that think for themselves.
Agent Teams
Teammates + Mailboxes
When one agent can't finish, delegate to persistent teammates via async mailboxes
Team Protocols
Shared Communication Rules
One request-response pattern drives all team negotiation
Autonomous Agents
Scan Board, Claim Tasks
Teammates scan the board and claim tasks themselves; no need for the lead to assign each one
Worktree + Task Isolation
Isolate by Directory
Each works in its own directory; tasks manage goals, worktrees manage directories, bound by ID