Pi Adapter — AOS Harness

This is the Pi CLI adapter for the AOS Harness. It runs both deliberation sessions and execution workflows inside Pi's terminal UI, wiring the harness runtime, event bus, workflow engine, and UI layer into Pi's interactive session model.

Prerequisites

• Pi CLI installed and on your PATH
• Bun runtime
• An Anthropic API key set as ANTHROPIC_API_KEY

Quick Start

cd aos-harness/adapters/pi && bun install
pi -e src/index.ts
# In the TUI, run:
/aos-run

Configuration

Model tier mapping is controlled via environment variables. Each tier corresponds to an agent class used during deliberation and workflow execution.

| Variable | Default | Purpose | |---------------------|----------------------|---------------------------------| | AOS_MODEL_ECONOMY | claude-haiku-... | Lightweight / high-volume calls | | AOS_MODEL_STANDARD | claude-sonnet-... | Standard deliberation agents | | AOS_MODEL_PREMIUM | claude-opus-... | High-stakes reasoning agents |

Set any of these in your shell or a .env file before launching Pi.

Pi differs from the other adapters: it keeps explicit tier models by default instead of deferring to the vendor CLI.

User Controls During Deliberation

Once a session is running, the following inputs are recognised in the TUI:

| Input | Effect | |------------|--------------------------------------------------------------| | /aos-run | Start a new deliberation | | halt | Hard-stop the session immediately | | wrap | End early — triggers final statements and memo synthesis |

When aos run launches Pi with an execution profile, the adapter skips arbiter kickoff and runs the workflow directly.

Architecture

The adapter is organised into four layers, each implemented as a dedicated module:

| Layer | File | Responsibility | |-----------------|---------------------|-----------------------------------------------------| | Agent Runtime | agent-runtime.ts | Instantiates and drives individual agent turns | | Event Bus | event-bus.ts | Routes messages between agents and the host shell | | UI | ui.ts | Renders deliberation output inside the Pi TUI | | Workflow | workflow.ts | Orchestrates phases: open, debate, synthesis, memo |

The adapter entry point (src/index.ts) implements the AOSAdapter contract defined in the framework runtime, ensuring consistent behaviour across any platform adapter.