Pi cold start: lazy-load the heaviest tools

Cut Pi's cold start by lazy-loading the heaviest tools. Pi users watching context cost.

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what to steal

Make your heaviest tools opt-in so their schema is paid for only when used.

Our takeaway from the source, not a quote.

Drawn from this card's sourced fields. Amber = older model named by the source. Rose = cut or replaced.

lws-pi-cold-start.toml

# Cut Pi's cold start by lazy-loading the heaviest tools
# source: https://lws.io/blog/pi-harness-cold-start/

[rig]
who     = "Pi users watching context cost"
author  = "Kevin Lewis"
date    = "not stated"

harness = ["Pi"]
models  = []

[keep]
  - Bash script + skill for single actions; MCP on demand for whole API surfaces
  - Most skills set disable-model-invocation: true
  - Linear MCP called through Apify's mcpc CLI client, one tool at a time
  - Self-built lazy-tools.ts extension makes fork, agent_browser and pi-codex-goal tools opt-in
[cut]
  - Heavy tools at startup
  - MCP registered at session start

thing	status	why (per source)
Heavy tools at startup	made opt-in	They made up most of the gap between Pi's 1,000-token floor and his 11,370-token cold start
MCP registered at session start	removed	Schema paid for only when used

Source: https://lws.io/blog/pi-harness-cold-start/ · checked 2026-10-14

Let the agent write its own skills instead of installing MCPs

steal → Ask your agent to write a small skill for the job before reaching for an MCP.

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by Armin Ronacher

~/rigs/mario-zechner-pi-four-tools.toml2025-11-30

Four tools. No MCP. No sub-agents. It ships.

steal → Before adding a tool, ask if read, write, edit and bash already cover it.

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~/rigs/nadimtuhin-mac-controls-pc-r….toml2026-09-01

Laptop as control room, home PC as the engine

steal → Run agents on an always-on box behind one model gateway; reach it with zero open ports.

Claude CodeCodexPi Any model behind 9Rout

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