Getting started

phi is a minimal terminal coding agent harness in Go — a sibling to Pi. It gives the model a small set of tools (read, write, edit, bash, …) behind a permission gate, keeps sub-agent work out of the parent context, and never lets MCP schemas pollute the prompt.

Install

macOS / Linux

curl -fsSL https://raw.githubusercontent.com/pulseaiclub/phi/main/scripts/install.sh | bash

Windows (PowerShell 5.1+)

irm https://raw.githubusercontent.com/pulseaiclub/phi/main/scripts/install.ps1 | iex

From source

Requires Go 1.26.3+ (see go.mod):

git clone git@github.com:pulseaiclub/phi.git
cd phi
make build          # produces ./phi
make install        # build and install into $GOBIN

Pick a model

First launch needs a model. Open the config editor — this creates the ~/.phi layout and writes ~/.phi/config.yaml:

phi config

Or set environment variables for a one-off run:

export PHI_MODEL=gpt-4o
export PHI_API_KEY=sk-...

Run it

phi

On first start, phi automatically creates ~/.phi/{bin,skills,extensions,session,jobs}. Search tools (fd, rg) download into ~/.phi/bin in the background when missing.

The TUI gives the model four core tools — read, write, edit, and bash — plus grep, find, and ls. The model uses these to fulfill your requests. External HTTP fetch is available via MCP when configured.

Note: a newer release available hint appears in the footer as 0.2.0 available · phi update. Run phi update to install it.

Footprint

phi aims to stay cheap to run and cheap to hack on. Numbers below are for a stripped release build (CGO_ENABLED=0, -ldflags="-s -w"), measured on macOS arm64 unless noted.

Next steps

• Configuration — config.yaml, environment overrides, workspace layout
• TUI — editor features, keyboard shortcuts, commands
• Headless mode — phi run -p "…" for one-shot agent runs
• MCP — wire up external tools without context death