~ / agents / pi-agent

Pi Agent

Ultra-minimalist coding agent slashing token costs by 70%

AgentRanks Score: 30/100 Open Source CLI Free + BYOK Updated June 2026

Overview

Pi Agent is the most token-efficient coding agent. Created by Mario Zechner (libGDX creator), it operates with just 4 tools and a 1,500 token system prompt. Each request uses ~2,600 input tokens vs Claude Code 27,000 — a 10x difference for the same task.

Specs at a Glance

Architecture

System Prompt

1.5K

Token Savings

70%

Open Source

Yes

GitHub Stars

45K

The Harness Tax

Portkey.ai benchmark (May 2026): given the same "hey" + "write a fibonacci script" prompts, Pi sent ~2,600 input tokens while Claude Code sent ~27,000 — pure harness overhead.

Recent Developments (June 2026)

Acquired by Earendil in May 2026. GitHub stars reached 45K. Community built pi-crust for session cost analytics.

Pros and Cons

Pros

70% token savings
Fully transparent
Multi-provider + local models
45K stars, post-acquisition

Cons

No MCP support
No plan mode
No sub-agents
Steeper learning curve

Verdict: Pi Agent delivers 70% token savings vs Claude Code — verified and real. No MCP, no sub-agents, but if you pay your own API bills, the savings are transformative.