A minimal terminal coding agent harness.

Sub-agents, hashline edits, a permission gate, and MCP without context death — in a ~12 MB binary that stays out of your way.

install.sh — zsh

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

Why phi

A harness that treats your context budget as the scarce resource it is.

Spawn isolated jobs and watch the run unfold — without stuffing every turn into the parent context.

Edit by @file#TAG and LINE#HASH anchors instead of rewriting whole files; stale anchors are rejected.

Gate or Ask before destructive tools fire. Safety is not optional when an agent can touch your tree.

Configure as many MCP servers as you want; tool schemas never enter the model prompt.

OpenAI-compatible or Anthropic — no vendor lock-in, switch models at runtime.

Package reusable procedures as SKILL.md; extend phi with Go — tools, commands, and event handlers loaded by yaegi.

Footprint

~12 MBrelease binary

~21 MBidle RSS per session

~40 mstime to first frame

6direct module deps

~22k LOCGo source, 32 packages

0Node / Electron / Python runtimes

Terminal first

phi — zsh